centre suisse d électronique et de microtechnique Scientific and Technical Report 2007

centre suisse d électronique et de microtechnique Scientific and Technical Report 2007

CSEM Centre Suisse d Electronique et de Microtechnique SA CSEM is a privately held research and development company active in: Applied Research Product Development Prototype and Low-volume Production Technology Consulting Its main fields of activity are micro- and nanotechnologies, microelectronics, systems engineering, microrobotics, photonics, information and communication technologies. In providing its high-tech know-how and technological expertise, CSEM strives to anticipate the future needs of different markets in terms of new technologies and offers its services to industrial customers. It also develops its own commercial activities either together with existing companies or through the creation of spin-offs and start-up companies and actively contributes to developing Switzerland as a hightech industrial location. In July 2007, a major of the Neuchâtel Observatory was integrated into CSEM to continue to develop space-related technologies. CSEM microsystems and miniaturization competences will be a clear advantage in terms of new developments in this area. Furthermore, CSEM opened in August a new research center in Landquart aimed at developing new technologies and competences in nanomedicine. CSEM operates from its headquarters in Neuchatel and also has centers in Zurich, in Landquart and at Alpnach, near Lucerne. It is also internationally active, in many European countries as well as overseas. CSEM is pursuing its geographical expansion strategy on a national as well as an international level. This growth offers medium- and long-term stability, essential in an R&D environment. At the end of 2007, the total number of employees at CSEM was 348 of which 26 were Ph.D candidates. Additionally, approximately 500 people are employed by the 26 spin-offs and start-ups created to date. In 2007, CSEM earned 58.1 million Swiss francs and presented a positive balance sheet.

CONTENTS PREFACE 5 RESEARCH ACTIVITIES IN 2007 7 ThruCOS From Biosensor Chip to Robust Analytical System 9 Counterfeit Machine Readable Covert Security Feature 10 MicroMec Microtechnology for Silicon Compliant Structures 11 ArrayFM An Atomic Force Microscope Using 2-Dimensional Probe Arrays 12 MicroStruc Integrated Optical Polymer Platform, Low Cost Assembly and Packaging 13 Encoder Nanometric Optical Absolute Position Encoder 14 RISE The Rich Sensing Concept 15 PackTime Zero-Level Packaging of Silicon Time-base 16 TissueOptics Portable SpO2 Monitor: a Fast Response Approach Tested in an Altitude Chamber 18 TUGON Compact MEMS-based Spectrometers for Infra-Red Spectroscopy 19 Solar Islands A Novel Approach to Cost Efficient Solar Power Plants 21 MICROELECTRONICS 23 Data Fusion for Wireless Distributed Tracking Systems 24 High Dynamic Range Versatile Front-End for Vision Systems 25 A High-Performance 2.4 GHz RF Front-End in a 90 nm Process 26 Direct Modulation RF Transmitter and Super- Heterodyne Low-IF Receiver Development Platform for 868 MHz and 915 MHz ISM Bands 27 Quasi-Harmonic Quadrature CMOS Relaxation Oscillator 28 Silicon Resonators: Thermal Compensation and Q Factor Optimization 29 icycam, a System-On Chip (SoC) for Vision Applications 30 Programmable Multi-Processor Engine for Ultra-Low- Power Single-Chip DVB Receiver 31 PHOTONICS 33 Miniaturized 360 -Camera Module for Collision Avoidance 34 Optoelectronic Test Equipment for Image Sensors and Systems Qualification 35 Highly Integrated Optical Linear Encoder 36 Compact Illumination Modules Based on High-Power VCSEL Arrays 37 Generic Framework for Feature Extraction in Vision 38 Efficient Screening and Formulation Optimization for Polymer LEDs 39 Polymer LEDs Patterned by Ink-Jet Printing 40 Optical Fill Factor Enhancement for Smart Pixels 41 MICRO AND NANOTECHNOLOGY 43 Dissolved Oxygen Sensor with Self-Cleaning and Self- Calibration 44 Microfabricated Membranes for Cell Layer Culture and Analysis 45 Metal Micro-Parts Fabrication 46 Scintillating Fiber Probes for Neurophysiology 47 Towards an Optical Switch with J-aggregates Monolayers 48 Colour Filters Using Polystyrene Microspheres 49 Towards Plasmon Enhanced Detectors 50 Unique Marking for Traceability and Anti-Counterfeiting Applications 51 Sol-Gel based Nanoporous Layers as New Sensing Interfaces 52 High Aspect Ratio Nanopores in MEMS Compatible Substrates 53 Nanoporous Membranes for Medical Diagnostics and Drug Discovery 54 Stimuli-Responsive Surfaces and Smart Coatings 55 Parallel Nanoscale Dispensing of Liquids for Biological Analysis 56 Electrospun Scaffolds for Tissue Engineering 57 Detection Methods for Nanotoxicology 58 Using Microtopography to Study Cell Elasticity 59 Composite Materials for Bone Implants 60 Simultaneous Detection of Four Antibiotic Families in Milk for Customer Safety 61 Smart Wound Dressing with Integrated Biosensors 62 Biosensors for Drug Prevention 63 Food Safety with the Help of a Miniaturized Laboratory 64 Wearable Biosensors in Protective Clothing 65 3

NANOMEDICINE 67 Robust Label-Free Biosensor using BRIGHT Technology 68 X-Ray Microscopy and Micrometer-Resolution Computer Tomography 69 SYSTEMS ENGINEERING 71 Micro-Vibration Analysis Setup for MEMS and MOEMS Characterization 72 Clinical Validation Results of the Long-Term Medical Survey System 73 ActiSmile A Portable Biofeedback Device on Physical Activity 75 Prediction of Neurocardiovascular Events 76 Reaction Sphere for Attitude Control 77 Continuous Arterial Blood Pressure Monitoring: Can the Cuff Be Got Rid of? 78 WISE Wireless Solutions for the Aeronautics Industry 79 UWB Antenna with Improved Bandwidth and Spatial Diversity using RF-MEMS Switches 80 FM-UWB A Low Data Rate (LDR) UWB Approach with Short Synchronization Time and Robustness to Interference and Frequency-Selective Multipath 81 A Wireless Sensor Network for Fire and Flood Detection at the Wild and-urban Interface 82 Exploiting Directive Antennas for Wireless Sensor Networks 83 A MAC Protocol for UWB-IR Wireless Sensor Networks 84 Optimum Operating Regimes for Wireless Sensor Networks 85 Wireless Sensor Networks for Monitoring Cliffs in the Alps 86 Control Electronics for Bio-Sensing Textiles to Support Health Management 87 Wearable Systems to Protect Rescuers and Firefighters during Operations 88 MEMS Based Miniature Catheter Probe for Ultrasound Imaging 89 Flip Chip Bonding on Polymers Die Attach and Leak- Tight Sealing 99 Optical / Fluidic Integration of Silicon-Based Hollow Waveguides 100 Novel Injection-Free Method for Intraepidermal Delivery of Large Molecular Weight Drugs 101 TIME AND FREQUENCY 103 PRN-cw Backscatter Lidar Prototype 104 Space Hydrogen Active Maser 105 COMLAB 107 Quality Control 108 ANNEXES 109 Publications 109 Proceedings 110 Conferences and Workshops 113 Competence Centre for Materials Science and Technology (CCMX) and National Center of Competence in Research (NCCR) Projects 121 Swiss Commission for Technology and Innovation (CTI) 121 European Community Projects 122 European Space Agency (ESA), European Southern Observatory (ESO) and Astrophysical Instrument Projects 123 Industrial Property 124 Collaboration with Research Institutes and Universities 124 Teaching 126 Theses 129 Commissions and Committees 130 Prizes and Awards 132 MICROROBOTICS 91 NanoHand A System for Automated Nano-Handling An Integrated EU Project 92 Microfactory A Flexible Assembly Platform 93 Isolation and Reversible Immobilization of Single Cells 94 Bonding of Glass or Silicon Chips with a Self-Sealing Photostructurable Elastomer 95 Sensor and Connector Integration into Microfluidic Systems using Biocompatible Tape Gaskets 96 Pressure Sensing Strip for Rapid Aerodynamic Testing 97 Pressure Sensing Strip Packaging Aspects 98 4

PREFACE Dear Reader, In this report, CSEM presents the main results of its research activities during the year 2007. Our research is aimed at commercial innovation and is very much orientated towards product applications. Using the know-how resulting from this special research, we maintain and increase our technology know-how, in order to create and develop our so-called technology platforms. We have defined seven priority domains for CSEM: Integrated Systems for Information Technology Photonics Micro- and Nanotechnology Nanomedicine Systems Engineering Micro robotics and Packaging Time and Frequency It should be noted that the research activities, as described in the following pages, are financed by federal (80%) and cantonal funds (20%). We would like to thank all public authorities, federal and cantonal, who made this report possible! We use our technology platforms for three main strategic goals: 1. To guarantee the sustainability of our technology competences and to be able to remain at the forefront of micro- and nanotechnology and related system engineering technology. 2. To make these competences available to our industrial customers, thus bringing new technologies to new markets. 3. To create start-ups in cases where new product ideas are not taken up by industry in Switzerland. As underlined above, CSEM research activities have mainly a commercial goal. Our measure of success is therefore the number of commercial applications and of patentable ideas. We would like to thank all our partners (EPFL, IMT, ETHZ, CEA / Léti-Liten, Fraunhofer Group Microelectronics VµE, and many others). And, most of all, we would like to thank all who have contributed to this report. I hope you will like it! Thomas Hinderling CEO, CSEM 5

6

RESEARCH ACTIVITIES IN 2007 Alex Dommann Today, industries are looking for complete solutions. In particular, innovative products exhibit a technological complexity, which can seldom be handled by a single technology provider. One of CSEM strengths is to offer this wide spectrum of technologies under one roof. CSEM is proud to offer its industrial clients a rich portfolio of technologies and a sound know-how of how to apply and realize innovative products based on Micro and Nanotechnologies. To maintain this portfolio in a healthy state the Swiss Federal and Cantonal Governments provide the necessary funding to run an applied research program. In the frame of the applied research nine multidisciplinary integrated projects (MIPs) built on several existing CSEM technologies were launched. MIPs are planned on a tight time-schedule of typically 2 years from the beginning to the realization of the demonstrator. Based on the market-oriented research strategy of CSEM ten MIPs were selected. A larger interdisciplinary demonstrator project is Solar Island (see below) fully financed externally but also dwelling on many different resources of CSEM, including industrialization. Further details on the nine MIP activities can also be found in this Scientific and Technical Report. ThruCOS From Biosensor Chip to Robust Analytical System In order to accurately control a biomolecular reaction, it is necessary to control the fluidic flow as well as the temperature of the reaction. Therefore, the wavelength interrogated optical sensing system (WIOS), previously developed at CSEM, has been updated with a fluidic cartridge and a temperature stabilized measurement chamber. In the future, this system will be industrialized by the start-up company Dynetix. Counterfeit Machine Readable Covert Security Feature By combining Micro and Nano technologies CSEM developed a security system to directly mark products and verify their authenticity. Due to forged products various industry sectors experience huge damages accounting to several hundred billion US Dollars a year. The development and implementation of new security systems opens a huge market to be exploited. In order to meet these requirements, CSEM designed a new system showing two main characteristics: A random pattern which is difficult to be copied was developed as a main security feature. In order to read those random patterns an instrument was developed which is able to read those features only by authorized persons. MicroMec Microtechnology for Silicon Compliant Structures The target of this project is the development of a microfabricated silicon compliant structure for mechanical applications and its understanding of the aging behaviour. MEMS can be made highly reliable, but it must however be noted that the failure modes of MEMS can be different from those of solid-state electronics. Therefore testing techniques are developed to accelerate MEMS-specific failures. Monocrystalline material and, especially, silicon is preferentially used due to its potential resistance against aging. ArrayFM An Atomic Force Microscope Using 2-Dimensional Probe Arrays In this multidisciplinary integrated project, an atomic force microscope able to investigate large sample surfaces with nanometric resolution was developed. Instead of a single probe, this novel microscope uses a 2-dimensional array of probes operating in parallel. Applications of this microscope include the biology domain, quality control, as well as material and surface characterization. MicroStruc Integrated Optical Polymer Platform, Low Cost Assembly and Packaging An integrated optics platform based on polymers as a low-cost alternative to glass and semiconductor waveguides has been developed from the design to the complete assembly and packaging of the devices. Although silica-on-silicon PLCs are well established they are still rather expensive as the processing and packaging is costly. Therefore, polymer PLCs potentially provide a promising alternative if low cost over the whole manufacturing process can be obtained. First demonstrators were already built. Encoder Nanometric Optical Absolute Position Encoder An optical absolute position encoder principle is presented which can combine many attractive features such as 24 bit resolution per 100 mm, compact design, optic-less shadow imaging, sampling rate exceeding 1 MHz and robustness. The detectable displacement is several hundred times smaller than the wavelength of the light and only 10 times larger than the diameter of the silicon atom. RISE the Rich Sensing Concept Within the RISE project a camera-based wireless sensor network for people detection and tracking purposes has been implemented. This sensor network, which is based on three vision sensors and two 3D time-of-flight cameras, is an ideal test-bed for long-term operational tests and the development of advanced algorithms. Furthermore, the installation is well suited for life demonstration purposes. PackTime Zero-Level Packaging of Silicon Time-base The development of a thermally compensated silicon timebase and the associated packaging to yield a miniature vacuum-sealed cavity around the resonator requires multidisciplinary competences in the fields of IC, MEMS design/fabrication, packaging, finite element modeling and metrology. This is the goal of the PackTime MIP. 7

TissueOptics Portable SpO2 Monitor: A Fast Response Approach, Tested in an Altitude Chamber Altitude is hazardous for the human body, with the oxygen delivery to the cells being jeopardized. The prototype of an advanced oxygen saturation monitoring sensor, embedded in a commercial earphone, was successfully tested in an altitude chamber. TUGON Compact MEMS-based Spectrometers for Infra- Red Spectroscopy Deformable MEMS diffraction gratings have great promise as tuning elements for external cavity lasers and for compact spectrometers. The challenge is to make high efficiency tunable MEMS gratings and incorporate them into practical devices. CSEM successfully designed, fabricated and tested MEMS gratings. Their spectral response was tested and the potential to design ultra-compact spectrometers based around this technology was shown. Solar Islands A Novel Approach to Cost Efficient Solar Power Plants Existing Solar Power Plants are too small, need complex constructions and drive systems to follow the altitude of the sun and have a limited use factor of the area. Therefore the generated energy is too expensive. The target of the new concept Solar Islands is to improve all these cost factors and to end up with a cost per kwh which is competitive with the energy costs of today. Furthermore the design as a floating island allows not only the application on land, but also on lakes, lagoons or on high sea. The vision is to build very large islands, floating on the pacific, that could contribute 1/4th of the estimated global energy demand in 2030. In 2007 the CSEM filed 23 new patent applications, 34 invention reports were submitted for examination and extension of 21 patents on prior patent applications in different countries were filed in. From the collaboration agreement between CEA / Léti and the Fraunhofer Group Microelectronics (VµE) three working groups emerged: the polymer platform, the joint design team and the joint reliability team. It is also important to note the creation of two new divisions at CSEM: Time and Frequency in Neuchatel and Nanomedicine in Landquart. 8

ThruCOS From Biosensor Chip to Robust Analytical System G. Voirin, R. Ischer, E. Bernard, G. Suarez, J. Auerswald, L. Davoine, M. Wiki, S. Berchtold, N. Schmid In order to accurately control a biomolecular reaction, it is necessary to control the fluidic flow and the temperature of the reaction. Therefore, the wavelength interrogated optical sensing system (WIOS), previously developed at CSEM, has been updated with a fluidic cartridge and a temperature stabilized measurement chamber. In the future, this system will be industrialized by the start-up company Dynetix. In recent years, CSEM has developed a biosensor platform based on glass chips. It is a general platform that has been used to demonstrate the potential of the wavelength interrogated optical sensing system (WIOS). However, this platform must be adapted to fit new applications, for example, an analytical laboratory system or a specific detection system for antibiotics [1]. Therefore, a specific fluidic system which allows several re-configurations has been developed. In addition, a temperature controller has also been integrated into the fluidic chip system to improve the reliability of the measurements. The glass chip consists of a glass substrate covered by a high refractive index waveguide layer, and several grating regions which form a matrix of sensing pads on the chip. Specific recognition molecules can be attached to each grating pad as a means of detecting different molecular targets. The specific binding of molecules translates into a change of the refractive index of the sensing layer. The refractive index is measured by determining the resonance wavelength of the waveguide grating pads using a wavelength tunable laser. To this end, the laser wavelength is periodically swept while the coupled light intensity is recorded. The laser illuminates eight grating pads simultaneously which are independently analysed. The designed fluidic cartridge is divided in two parts: the first part is a support for the glass chip that defines the microfluidic channels over each of the grating pads using a thickness controlled double sided tape; the the second part defines the fluidic channels for addressing each individual sensing pad. Two different fluidic circuits have been designed for a multipurpose laboratory analytical system. In one design, each pad is addressed individually; there is one fluidic inlet and one fluidic outlet per grating pad. In the other design, the grating pads are serially addressed and the cartridge has only one inlet and one outlet (Figure 1). The first design will be used for the functionalization of the grating pads with different capture molecules, while the second design will be used to test a fluid sample for different target molecules in a single measurement. IN OUT Cross section 4cm Cartridge thinned down ca. 0.5mm for temperature stabilization of flow-cell region Size ca. 8mm x 14mm with replication technologies in plastic substrates was also performed; however, the performances are not yet sufficient and the fabrication will be optimized. For analytical applications in the laboratory, the temperature of the biomolecular reaction must be controlled and reproducible. In order to maintain a fixed temperature on the chip and in the measurement fluid, the cartridge is enclosed in a temperature stabilized measurement chamber. The temperature of the chamber is then set using a Peltier element controlled with a feedback-loop system. Inlet Outlet Figure 2: View of the fluidic cartridge with one inlet and one outlet The system depicted in Figure 3 was used successfully in a set-up phase to implement the immunoassay protocol for antibiotic detection on the WIOS instrument in the frame of the CCMX project Lab-On-A-Chip [1]. The temperature control system is able to stabilize the temperature to within 0.01 C in the range of 15 to 40 C. Figure 3: Temperature stabilization system including the cartridge WIOS and supporting development have lead to the creation of the start-up company Dynetix [2], which will take over the industrialization and the commercialization of the analytical system for laboratory applications. This work was funded by the OFFT, the cantons of Central Switzerland, the Micro Center Central Switzerland (MCCS), and European Projects FP6-NMP-STRP-032131 & NMP3-CT- 2007-026549. CSEM thanks them for their support. Fluidic Gasket - double side adhesive tape - patterned by laser cutting WIOS Chip Figure 1: Schematic of one of the fluidic circuitries in the cartridge Fluidic cartridges were fabricated using micromilling technology in PMMA (Figure 2). Fabrication of the WIOS chips [1] G. Voirin, et al., Simultaneous Detection of Four Antibiotic Families in Milk for Customer Safety, in this report, page 61 [2] www.dynetix.ch 9

Counterfeit Machine Readable Covert Security Feature J. Pierer, U. Gubler, N. Blondiaux, R. Pugin, C. Keck, H. Walter By combining Micro and Nano technologies CSEM has developed a security system to directly mark products and verify their authenticity. Due to forged products various industry sectors experience huge damages accounting to several hundred billion US Dollars a year [1]. Consequently, extensive efforts are made to increase protection of products at risk. The development and implementation of new security systems opens a huge market to be exploited. However, to understand this market, one has to understand the characteristics of security features. Most safety features and safety equipment are safe only for a short period of time, depending on how long it takes for forgers to counterfeit the technique. Extending the secure period of a safety device is therefore one of the most important requirements when developing new security systems. In order to meet these requirements, CSEM designed a new system showing two main characteristics: A random pattern [2] which is difficult to be copied was developed as a main security feature In order to read those random patterns an instrument was developed which is able to read those features, but is no use to somebody who does not know what to look for. By process control these patterns can be designed to meet certain specifications with regard to the features of average size and consequently average period. Their organization, however, remains completely random. The coherent light of a laser is used to illuminate the pattern. The light is scattered on each element of the structure. Every single element can then be seen as a new source of light. Investigating the intensity of the scattered light at any point in space will result in a value given by the superposition of the light of all these sources. Depending on incidence angle, structure period and wavelength of the light one gets a particular intensity distribution. However, since the features are randomly aligned the image shows a so called speckle pattern (Figure 1). Analyzing characteristic parameters of the speckle pattern or the smooth distribution identifies uniquely either a particular security item (e.g. credit card) or the technology with which the pattern was created. We have built a small electronic prototype to demonstrate the feasibility and ruggedness of this new technique. A small laser diode with an integrated focusing lens was used as source, a silicon photodiode array as detector to build the prototype. All components, including a micro controller, were assembled on a printed circuit board. The micro controller compares the sample under investigation with an inbuilt reference and communicates the result via a green/red LED to the human observer. For obvious reasons credit cards were chosen to demonstrate the new security feature. The credit card is inserted into the device through a standard smartcard holder. The cardholder holds the credit card in place with a repeatable accuracy exceeding 40 µm, which is sufficient for these purposes. As can be seen in Figure 2 the entire setup fits into a small box leaving plenty of space. Figure 2: Demonstrator The results of this project have proven that the implementation of these newly developed security features is possible with very simple low cost components. CSEM security system is difficult to counterfeit and is mass producible. The developed authentication device is easy to use, compact and can be built in into other devices, such as automatic teller machines. CSEM new security features offer a promising way to prevent counterfeiting for an extended period of time. [1] G. W. Abbot, L. S. Sporn, Trademark Counterfeiting 1.03[A] Figure 1: Image of a speckle pattern on a paper target, left: small spot illuminated, right: large spot illuminated [2] Patents pending When illuminating a small spot of the security feature (about 30 µm) a well distinguishable speckle pattern becomes visible. By enlarging this area up to a few millimetres, the speckles are averaged and a smooth distribution is visible. 10

MicroMec Microtechnology for Silicon Compliant Structures C. Verjus, J.-M. Major, T. Overstolz, A. Hoogerwerf, A. Ibzazene, A. Neels, A. Schifferle, A. Dommann The target of this project is the development of a microfabricated silicon compliant structure for mechanical applications and its understanding of the aging behaviour. MEMS can be made highly reliable, but it must however be noted that the failure modes of MEMS can be different from those of solid-state electronics. Therefore testing techniques must be developed to accelerate MEMS-specific failures [1]. of the thin Silicon beam. The appearance of diffused scattering in the RSM (Figure 2) is related to the beam bending strain. Elastic deformation in the test structure was observed. Monocrystalline material and, especially, silicon is preferentially used due to its potential resistance against aging. However, quantified results of this fact are rarely published. The reasons are manifold; however they are also related to the surface roughness as well as to the defect concentration of the etched surfaces due to the ion bombardment [2]. Deep reactive ion etching (DRIE) of silicon-on-insulator (SOI) substrates allows the fabrication of structures with arbitrary shapes (2D) that are vertically extruded by removing excess silicon. Test structures can be built from single crystalline silicon by DRIE processes. Mechanical tests on these structures in relation with simulations of stresses and the experimental determination of the strain / stress behavior and defect analysis by High Resolution Diffraction Methods (HRXRD) give very important information about the device and its long term stability. A silicon beam structure processed by DRIE (Figure 1) has been studied. Simulations have been done related to mechanical shifts applied to the entire silicon structure which results in the generation of strain in the small silicon beams having a thickness of 50 µm. In dependance of the position of the beam in the structure, stresses ranging from about 60 to 1100 MPA are calculated by simulations. Figure 2: Diffused scattering in the RSM of compliant structure The study of mechanical tests combined with simulations and related HRXRD measurements results in a better understanding of the material properties. The generation of defects in the material and their increase related to mechanical stresses or other environemental influences is an important issue as it is directly related to the device performance and its long term stability. [1] A. Dommann, G. Kotrotsios, A. Neels, MEMS Reliability and Testing, MST News, (2007) [2] E. Mazza and J. Dual, Mechanical behavior of a µm-sized single crystal silicon structure with sharp notches. J. Mechanics and Physics of Solids 47 (1999) 1795-1821 Figure 1: Silicon beam structure processed by DRIE High resolution x-ray diffractometry (HRXRD) measures the strain of a crystal. This is an accurate, non destructive method applied in the field of MEMS to obtain quantified results on the crystalline disorder. CSEM therefore applies an X-ray rocking curve method, which measures the strain of a crystal as well as the defect concentrations. Applying a mechanical force to a perfect silicon single crystal results in a deformation which is directly related to a change of the crystal strain profile. In addition, reciprocal space mapping (RSM) visualizes the strain generation related to the bending 11

ArrayFM An Atomic Force Microscope Using 2-Dimensional Probe Arrays A. Meister, J. Polesel-Maris, S. Dasen, G. Gruener, M. Schnieper, T. Overstolz, A. Vuillemin, C. Gimkiewicz, R. Ischer, P. Vettiger, H. Heinzelmann In this multidisciplinary integrated project, an atomic force microscope able to investigate large sample surfaces with nanometric resolution was developed. Instead of a single probe, this novel microscope uses a 2-dimensional array of probes operating in parallel. Applications of this microscope include the biology domain, quality control, as well as material and surface characterization. Since the emergence of the atomic force microscopy (AFM) in the eighties, the topographic investigation of a sample surface at a nanometric scale has become a standard technique. AFM techniques can also be used to measure various kinds of local interactions, such as magnetic, electrostatic, or binding forces, electrical conductivity, or to determine mechanical properties such as elasticity or friction. Standard AFMs use a single probe, and, due to the scanning process, are rather slow in terms of data acquisition. The aim of this project is to develop an AFM functioning with a large probe-array instead of a single probe, increasing thus the throughput of the instrument. The realized instrument is shown in Figure 1. The implementation of arrays instead of a single probe requires new functionalities compared to a standard AFM instrument, such as the parallel read-out of each probe, the spatial alignment of the probe-array above the sample surface, and a dedicated software to drive the instrument and for the user interface. The correct positioning of the probe-array above the surface is realized using a micropositioning stage with 6 axis of freedom (Hexapod) with micrometric accuracy. The sample is mounted on a piezoelectric nanopositioning stage, and is scanned with a nanometric precision while the array probes the sample surface. not today commercially available, and have therefore also been developed within this project. Since the cantilever deflection detection is not integrated in the probe array, this latter can be passive, and thus be produced in a cheap way. Two different processes leading to two different and complementary kinds of probes were developed. The first process relies on a sol-gel replication of the probe arrays in a polymeric structure, which are foreseen as disposable probe arrays to be used for parallel force spectroscopy in biology. The second process is based on micromachining of silicon wafer, and enables the production of cantilever with sharp tips dedicated to high resolution imaging. Examples of realized probe arrays are shown in Figure 2. Figure 2: Left: Optical micrograph of a probe array fabricated by solgel replication process (scale bar: 500 µm). Right: Scanning electron microscope micrograph of a silicon probe array fabricated by micromachining. The ability of this instrument to operate AFM cantilever arrays opens new application domains, such as multi-parameter surface investigation using a probe array with different cantilever functionalities, parallel force spectroscopy with improved statistics, or large scale topographic imaging. The application field covers: Figure 1: Developed AFM instrument that is able to operate with an array of probes in parallel In contrast to standard AFMs, where the read-out of the cantilever deflection is detected using a reflected laser beam, in this instrument the parallel read-out of the cantilever-array is based on optical interferometry using a Linnik interferometer. The interferogram, which arises from the combination of both reference and measuring optical beams, is detected by a CMOS camera and analyzed by the software. The characterization of the optical set-up showed an ability to measure cantilever deflections as small as 1 nanometer. The development and fabrication of the probe arrays made of micro-cantilevers is another important issue. Such arrays are Quality control: metrology, surface roughness, defect analysis. Biological and medical applications: parallel cell indentation (determination of the cell elasticity), parallel force spectroscopy to measure cell-cell interaction or antibody-antigen binding (to detect the presence of the target molecule on the receptor molecule in affinity assays). Large scale imaging: topographic characterization at a nanometric range, large scale surface studies such as friction or elasticity with piconewton resolution. The partial support of the Swiss Federal Office for Education and Science (OFES) in the framework of the EC-funded project NaPa (Contract no. NMP4-CT-2003-500120) is gratefully acknowledged. 12

MicroStruc Integrated Optical Polymer Platform, Low Cost Assembly and Packaging A. Stump, P. Schüepp, T. Overstolz, C. Bosshard, U.Gubler An integrated optics platform based on polymers as a low-cost alternative to glass and semiconductor waveguides has been developed from the design to the complete assembly and packaging of the devices. Planar lightwave circuits (PLCs) are replacing optical modules with single elements assembled together more and more. The integration of optical functionalities in a planar design with batch processing can be seen analogous to the shift from single electronic components to integrated microelectronics. and the fiber boots molded from silicone fit exactly into these U-holes. At the end of the boots a small hole allows threading of the fibers (Figure 1). Due to this design the insertion of the assembled PLC into the preform is straightforward. The boots are put on the fibers and then pushed into the preform. Unlike in microelectronics no standard material exists like silicon. Although silica-on-silicon PLCs are well established they are still rather expensive as the processing and packaging is costly. Therefore, polymer PLCs potentially provide a promising alternative if low cost over the whole manufacturing process can be obtained. The polymer PLC technology platform developed in the past years at CSEM addresses these issues: The waveguide material can be produced inexpensively in volumes. The structuring of the PLC is based on direct UVpatterning, which saves cost compared to the traditional dry-etch process (as e.g. silica-on silicon technology) The assembly is carried out passively in a pick-and-place process without cost and work intensive active alignment The encapsulation of the assembly is done by a molding process similar to the electronics and IC industry. Figure 2: Sketch of the approach to package PLCs with electrodes. As the PLC is wider than the carrier, the electrodes on the PLC are still accessible. In the case of thermo-optic devices the electrodes on the PLC have to be contacted after the flip-chip step. In this approach the PLC is designed wider than the carrier underneath so that the electrodes are still accessible after the flip-chip step (Figure 2). The overall process is simple and low cost. Before molding the assembly into the package, electrical legs can be connected to the PLC (Figure 3). Figure 3: Model of a thermo-optic PLC with electronic contacts in the encapsulated module built up as described above. Figure 1: Sketch of encapsulation approach: the assembly is inserted in the pre-form and filled with a sealant polymer. To reduce stress on fibers boots are provided on both ends. The encapsulation of PLC assemblies is an important part of the process. Special preforms were designed and injection molded. The trough is a LCP (liquid crystal polymer), which acts as a barrier for gas or humidity to diffuse through the package wall. The feedthroughs for the fibers are U-shaped Although the main application area is the telecom market, a low-cost integrated optics platform with an adequate packaging technology is also interesting for other fields. Various special applications in the area of sensing are possible such as integrated spectrometers or interferometers, hybrids with micro-fluidics in life sciences, or layouts for gas sensing. This work has been supported by the Micro Center Central Switzerland MCCS. 13

Encoder Nanometric Optical Absolute Position Encoder P. Masa, E. Franzi, J. Pierer, P. Glocker, J.-M. Mayor, D. Fengels An optical absolute position encoder principle is presented which can combine many attractive features such as 24 bit resolution per 100 mm, compact design, optic-less shadow imaging, sampling rate exceeding 1MHz and robustness. The detectable displacement is several hundred times smaller than the wavelength of the light and only 10 times larger than the diameter of the silicon atom. Combining all the attractive features in a position encoder such as high-resolution, absolute, compact, high-speed is a real challenge today. Such an encoder clearly has a great potential in various fields like robotics, automation, machine tools, automotive, aerospace; just to mention a few. An optical absolute position encoder technology developed at CSEM has the potential to combine all these attractive features. Nanometric resolution has been established using ultra-compact USB camera, linear glass scale, LED illumination, without the need for optics, as shown in Figure 1. Note that the detectable displacement is several hundred times smaller than the wavelength of the light and only 10 times larger than the diameter of the silicon atom. Highspeed opto-asic implementation by CSEM proved that sampling frequency of such an encoder may exceed 1MHz [1]. Optic-less shadow-imaging permits compact design and major cost reduction. A flexible, customizable experimental/demonstrator platform is under development, which is based on the icycam chip [2]. The image captured by a 320 x 240 high dynamic range pixel array is processed in real-time on the same chip by the 32-bit icyflex processor. Prototyping of rotary, linear and even 2D position encoders can be supported by this platform. One of CSEM goals is to demonstrate the potential in robotics, to combine the technologies of the absolute encoder and the PreciAmp servo-drive to build the CSEM next generation direct-drive MicroDelta robot. Figure 2: Image of a double-track linear scale consisting of a 12 bit Manchester code and 100 µm regular grating. Image obtained by ultra-compact USB camera and shadow imaging. Figure 1: Shadow imaging experimental setup consisting of a compact USB camera, transparent scale and LED illumination (LED not shown here) Coarse absolute position measurement is obtained by decoding the subsection of the Manchester code (typically 8-16 bits), which is seen at a given position by the sensor. Fine relative position measurement is attained by Fourier analysis of the regular grating at the fundamental frequency. Robustness, precision and very high resolution is guaranteed by heavily oversampling the pattern (typically 8-16 pixels per pattern period) and relying on the phase information which is distributed in the entire image among hundreds or thousands of pixels. The fine measurement principle is shown in Figure 3. One possible interpretation of the method is that each pixel represents one point in the cloud of measurements and the center of gravity gives the final result. The combination of the coarse and the fine measurements yields very high-resolution absolute position, typically 24 bits for a Ø 32 mm rotary or 100 mm linear encoder. The maximum attainable resolution scales linearly with the diameter of the rotary or with the length of the linear encoder. Figure 3: Robust, high-precision position measurement principle [1] A. Mortara, et al., An Opto-Electronic, 18-bit/revolution Absolute Angle and Torque Sensor, ISSCC 2000 Digest [2] C. Arm, et al., icycam, a System-On Chip (SOC) for Vision Applications, in this report, page 30 14

RISE The Rich Sensing Concept A. Hutter, D. Beyeler, A. Brenzikofer, E. Grenet, F. Rampogna, L. von Allmen, C. Urban, P. Nussbaum Within the RISE project a camera-based wireless sensor network for people detection and tracking purposes has been implemented. This sensor network, which is based on three vision sensors and two 3D time-of-flight cameras, is an ideal test-bed for long-term operational tests and the development of advanced algorithms. Furthermore, the installation is well suited for life demonstration purposes. The multi-disciplinary project RISE targets the elaboration of a heterogeneous sensor network for the purpose of people detection and tracking within home and building areas. As a result of the first project phase, which ended in 2007, a demonstrator has been implemented in the CSEM entrance hall. The demonstrator is based on two different camera types: low power vision sensors [1] and 3D time-of-flight cameras [2]. Vision sensors exploit the contrast information of the observed scene and are distinguished by their huge dynamic range of 100 db as well as the low power consumption of 80 mw. 3D time-of-flight cameras, on the other hand, provide a three-dimensional representation of the observed scene. Within the RISE project the vision sensors are used to detect and track persons and objects whereas the 3D time-of-flight cameras are utilized in order to provide additional height information of the detected objects. Further essential components of the system are the wireless communication link together with the data fusion entity. In this article the basic concept together with the implemented interworking of the cameras and the wireless system is described. The data fusion algorithm and the related issues are subject to a separate article [3]. The demonstration test-bed covers an area of approximately 150 m 2. The vision sensors operate with a 2.6 mm fish-eye objective, which in turn provides a relatively large field of vision, e.g. the area that is observed by one particular camera. As such, the vision sensors have overlapping fields of vision and cover the entire entrance area ranging from the entrance over the two entrance side areas to the reception desk. The field of vision of the 3D time-of-flight cameras, which require active illumination, is limited to an area with a diameter of approximately 2 meters. One 3D camera is positioned close to the entrance whereas the second 3D camera is located right in front of the reception desk. The network coordinator, which acts as wireless data concentrator, is located in a closed box with wooden shielding right under the central monitor in the reception hall. An illustration of the disposition of the different vision sensors and the 3D cameras is presented in Figure 1. A new sensor platform that is capable of hosting both, the vision sensor as well as the 3D camera, and that provides the required processing and communication resources has been designed. The sensor platform includes a Blackfin 533 digital signal processor running at 500 MHz, 2 MB Flash and 32 MB SDRAM memory, an Ethernet connection for test and debugging purposes and a hardware socket that connects different wireless modules. For the purpose of the RISE project the use of the 2.4 GHz ZorgWave module [4] was selected, since the communication characteristics of the module together with the associated protocol stack respond ideally to the throughput and delay requirements of the system. The communication concept foresees that each sensor node communicates the position data of each detected object together with a time stamp and some additional object information in total around 100 Bytes to the network coordinator. Transmission at regular intervals (about every 100 ms) is mandatory in order to guarantee tracking consistency. In addition to this regular traffic, specific data requests (as for instance the transmission of the currently observed image) should be possible. This results in a required data rate of approximately 8 kbps for the regular traffic of each sensor node plus some additional bandwidth for the irregular data request traffic. In order to comply with these requirements the IEEE standard 802.15.4 (which is identical to the basic protocol layers of the ZigBee system) was selected. The network operates in beacon-enabled mode with a beacon interval of 123 ms and the guaranteed time slot (GTS) option of the standard is used to transmit the regular traffic of up to seven sensor nodes. The GTS option allows contention-free channel access meaning that data packets are transmitted with guaranteed throughput and delay. It should be noted that the GTS feature, which is not a mandatory option in the standard, was implemented in the CSEM K15 stack. The GTS portion requires approximately 44% of the available transmission time between network beacons so that approximately 67 ms remain available to accommodate irregular data requests. This corresponds to a sustainable data rate of approximately 15 kbps in situations with multiple simultaneous data requests. The RISE project demonstrator is fully operational and can be visited at CSEM upon request. Figure 1: Disposition of the vision sensors and 3D cameras in the CSEM entrance hall [1] S. Gyger, et al., Low-power Vision Sensors, CSEM Scientific and Technical Report 2004, page 17 [2] T. Oggier, et al., Miniaturized 3D time-of-flight Camera with USB Interface, CSEM Scientific and Technical Report 2002, page 37 [3] E. Franzi, et al., Data Fusion for Wireless Distributed Tracking Systems, in this report, page 24 [4] CSEM Wireless Sensor Networks, www.csem.ch/wsn 15

PackTime Zero-Level Packaging of Silicon Time-base D. Ruffieux, J. Baborowski, M. Fretz, S. Grossmann, C. Henzelin, I. Kjelberg, T.C. Le, J.-M. Mayor, A. Pezous, A.-C. Pliska, A. Schifferle, G. Spinola Durante, Y. Welte The development of a thermally compensated silicon time-base and the associated packaging to yield a miniature vacuum-sealed cavity around the resonator requires multidisciplinary competences in the fields of IC, MEMS design/fabrication, packaging, finite element modeling and metrology. The low power frequency and timing market relies almost exclusively on quartz resonators to derive precise and low aging references thanks to the availability of crystal cuts with null first order temperature coefficient on frequency (TCF). Silicon on the other hand appears quite attractive from a miniaturization perspective but suffers from a severe drawback with a TCF close to -30 ppm/ C whatever the crystal orientation. Consequently, electronic compensation that can possibly be combined with structural compensation [1, 2] appears as one of the most promising workarounds to reach performances similar or better than that of AT-cut quartz crystal achieving null first and second TCF. The development of such a high performance, miniature and low power real time silicon clock (RTC) together with the associated packaging technology entails multidisciplinary competences in IC and MEMS design/fabrication, packaging, FEM and metrology. The activities ongoing in each of these fields are described in the following sections after an overview of the system is presented. Figure 1 shows a cross-section of the envisioned miniature whole silicon time-base that consists of a rear side packaged silicon resonator integrated on a SOI substrate that is assembled and interconnected by a flip-chip and reflow process to an IC capping die generating the thermally compensated clock. The reflow process is performed under vacuum and should ensure hermeticity of the cavity that is formed around the resonator to take advantage of the high quality factor of the latter and minimize any aging of the time-base. Figure 1: Cross-section of the miniature zero-level packaged silicon timebase with a vacuum-sealed cavity around the resonator A FEM CAD model of the complete resonator including its package has been developed to help determine the sensitive parameters that affect the resonator frequency during and following the assembly process and could then be responsible for excessive aging. Thermo-mechanical simulations are also very valuable to predict the performance of the compensated time base that relies on a good matching of the resonator and sensor temperature and that may be affected during thermal transients. The lack of availability of precise data for the stiffness of the materials involved in the fabrication of the resonators and their temperature dependency has motivated the development of an optical metrology bank [3] and dedicated test structures that should help future resonator design and allow more precise FEM analysis once measurement and extraction is completed. The resonator exploits a high-q in-plane, longitudinal, extensional mode and is formed of a T-shaped silicon beam, typically 1000 x 250 µm 2, anchored at its base end, with an inertial mass at each extremity. Figure 2 shows some extensional resonators after processing. The driving voltage is applied on the piezoelectric layer only in the central part of the beam. The resonators are built from a (100) oriented Silicon on Insulator (SOI) substrate. Structure of the resonator consists mainly of single crystal silicon that is oxidized on both sides, and that is topped by AlN and its electrodes. Polycrystalline piezoelectric (002) AlN films are deposited by magnetron sputtering on Pt (111) electrode. A metal ring is patterned around the resonators for subsequent assembly with the capping wafer. Figure 2: Microphotograph of fabricated resonators Si resonators in extensional mode, oriented along <110> with a thickness of 105 microns, and activated by 2 micrometers of AlN, exhibit a Q factor under vacuum of 140000 and k 2 eff around 0.05%. Q factor at atmospheric pressure is up to 20000, and increases linearly when the pressure decreases. In order to obtain the maximum Q factor the pressure must be below 0.1 mbar. The measured impedance in air and under vacuum is plotted in Figure 3. The resonance frequency of these resonators is close to 960 khz, the motional resistance is in the range of 200 Ohm and the linear TCF is -28 ppm/ C. Figure 3: Impedance plot of high Q resonator in air and vacuum 16

In order to optimize the performances of the resonator and guarantee long-term frequency stability, one needs to perform hermetic packaging under reduced pressure. The rear side of the resonators is closed hermetically by low temperature fusion bonding (with Si wafer) or by anodic bonding (with Pyrex). Both methods require an extremely smooth surface of the wafer. The resonator chips are then vacuum encapsulated using silicon caps (ultimately working ICs) and AuSn (80% wt Au) soldering technology. Metallic alloy materials provide both low-permeability sealing characteristics as well as electrical conduction for the resonator driving interconnects. The AuSn electroplating process was carried out at the Fraunhofer Institute for Reliability and Microintegration (IZM FhG). Vacuum sealing of the resonator chips is done through a twostep process: Tacking of the sealing cap on the resonator chip at a temperature below the AuSn melting point using flip-chip Reflow under vacuum in a dedicated oven The tacking methodology proved to be successful. Taguchi runs using thermo-compression parameters (temperature, force, dwelling time) as variable experimental factors were carried out. Figure 4: Photograph showing a chip on board assembly of a miniature time-base [1] J. Baborowski, et al., Piezoelectrically Activated Silicon Resonators, IEEE Frequency Control Symposium, 1210-1213 (June 2007) [2] B. Kim, et al., Si-SiO2 Composite MEMS Resonators in CMOS Compatible Wafer-Scale Thin-Film Encapsulation, IEEE Frequency Control Symposium, 1214-1219 (June 2007) [3] J.M. Mayor, et al., Micro-Vibration Analysis Setup for MEMS and MOEMS Characterization, in this report, page 72 Reflow process development, where resulting vacuum level is monitored through Q factor measurements, is on-going. A differential oscillator structure has been chosen to minimize the circuit power dissipation despite the large shunt capacitance of the resonator (~10 pf). A programmable fractional divider is used to generate a thermally compensated 32768 Hz clock from the 960 khz oscillator signal that drifts by -28 ppm/ C. The output of a high resolution temperature sensor integrated on the same die is used by a sequencer to implement an open-loop compensation algorithm that requires initial calibration of the resonator absolute frequency and thermal drift. The state machine has been implemented on an external FPGA to yield greater flexibility. Communication with the IC to read the thermal sensor indication and update the fractional divider ratio is ensured via a serial bus interface. Figure 4 shows a photograph of a miniature packaged resonator that has been glued above the IC mounted over a printed circuit board. The close vicinity of the resonator and the thermal sensor located within the IC minimize any thermal gradient that would affect the compensation accuracy. Extensive testing of the IC with the miniature packaged resonators will be initiated once satisfactory vacuum levels are reached within the micro-cavity to assess the performance of the thermo-compensated time-base. 17

TissueOptics Portable SpO2 Monitor: a Fast Response Approach Tested in an Altitude Chamber C. Verjus, V. Neuman, J. Solà I Caros, O. Grossenbacher, S. Dasen, O. Chételat Altitude is hazardous for the human body, with the oxygen delivery to the cells being jeopardized. The prototype of an advanced oxygen saturation monitoring sensor, embedded in a commercial earphone, has been successfully tested in an altitude chamber. Oxygen is vital to maintain the basic metabolism of cells in the human body: in the absence of oxygen for a prolonged amount of time, cells would die. In critical situations like aviation, severe hypoxia periods reduce oxygen delivery, leading subjects to unconsciousness and compromising the security of the crew. Thus, continuous monitoring of oxygen delivery to cells is a relevant indicator of the health of a person. including a servo-controlled loop and an offset correction to improve the dynamic range of pulse oximetry sensors. For healthy people under normal oxygen delivery situations, about 98% of haemoglobin (Hb) in the blood combines with oxygen to form oxy-haemoglobin (HbO2). The so-called arterial oxygen saturation (SaO2) is calculated as the ratio of HbO2 to total haemoglobin (Hb + HbO2). When this saturation parameter is assessed by means of optical non-invasive techniques it is commonly known as SpO2. Pulse oximetry is a widespread, non-invasive method used in clinical environments to determine arterial oxygen saturation. Two light beams of different wavelengths are injected into the skin surface and transmitted or backscattered parts of them are retrieved. The technique is then based on the photoplethysmographic effect (measurement of a change of volume by optical means) and on the local characteristics of the absorption curves of hemoglobin and oxy-hemoglobin at two different wavelengths. SpO2 sensor products are available today, but they are incompatible with comfortable and non-obtrusive long-term monitoring. CSEM has launched a strategic activity to develop oximeter probes for different body positions (finger ring, ear cartilage, sternum, etc.). Figure 2: Test subject in the cockpit mock-up and computer logging of the reference blood oxygen saturation value from the Biopac and the value measured with the CSEM sensor. The measurements were conducted during the cockpit ventilation assessment tests of SolarImpulse [1] in the altitude chamber of the Fliegerärztliches Institut der Luftwaffe FAI/AMC Schweiz in Dübendorf. Two tests were performed on this occasion with two different test subjects. The tests aimed at obtaining in the shortest time possible the cockpit air composition for oxygen and carbon dioxide, as it will change at high altitude. Each test lasted about 4 hours. The time for a climb to 3000 m was around 20-30 minutes. The altitude chamber is internally ventilated, in order to provide normal atmosphere conditions in the environment of the cockpit mock up. Figure 1: Comparison between the blood oxygen saturation given by the reference sensor from Biopac and calculated by the CSEM sensor during the whole test. TissueOptics is a CSEM Multidisciplinary Integrated Project aiming at improving its expertise of non-invasive optical measurements in human tissue. One of the innovations already developed in this project is a dedicated electronic A Biopac Sensor, using a fingertip probe, connected to a laptop computer logging the measured values acts as a reference for the CSEM SpO2 sensor. The CSEM SpO2 sensor uses an earlobe probe integrated into an earphone. The results calculated in real time by the CSEM sensor are fully in agreement with the reference values from the Biopac. [1] www.solarimpulse.com 18

TUGON Compact MEMS-based Spectrometers for Infra-Red Spectroscopy M. Tormen, R. Lockhart, J-M, Mayor, R. P. Stanley Deformable MEMS diffraction gratings have great promise as tuning elements for external cavity lasers and for compact spectrometers. The challenge is to make high efficiency tunable MEMS gratings and incorporate them into practical devices. CSEM has successfully designed, fabricated and tested MEMS gratings. Their spectral response has been tested and the potential to design ultra-compact spectrometers based around this technology has been shown. In Optical MEMS, the family of diffractive MEMS is interesting for a wide range of applications because they can be compact, fast and their narrow spectra response can be used in spectrometers and for tunable lasers [1]. Commercially available diffractive MEMS are used in displays, in spectroscopy and optical telecommunications [2, 3]. KOH etching. This technique is widely used to make V-grooves. It yields smooth angled surfaces while maintaining the mechanical properties of the grating beams. Extending this technology to a MEMS device has been a challenge. The MEMS grating shown in Figure 1 is actually a blazed grating. Optical grating 5 mm Figure 2 : A minature monochromator in the lab. The light is coupled into and out of the grating (bottom centre) using a pair of fibres and collimating lenses. For scale the MEMS chip is 12 x 6 mm. Comb drives Figure 1: Overview of a tunable MEMS grating. The white dotted region denotes the optical grating which is actuated by four sets of electrostatic comb drives. CSEM has been developing a tunable MEMS grating technology, and this report demonstrates how it could be incorporated into a compact spectrometer. In the spectrometer, the MEMS grating is stretched like an accordion. The change in the size of the grating changes directly the period of the grating and hence the wavelength tuning of the grating. This method of tuning is completely different from normal spectrometers where the grating is rotated. The advantage of MEMS grating is that the complex mechanics for controlling the rotation of the grating in the standard configuration is replaced by simple electrostatic comb drives which stretch the MEMS grating. Figure 1 shows a processed MEMS device [4] which comprises the tunable optical grating and the electrostatic comb drives which stretch the grating. The device has been fabricated using standard MEMS manufacturing techniques. The complete die measures 6 x 3 mm, with a 1 mm x 1 mm grating. The grating itself is formed from free-standing beams with a 12 µm period and a 50% duty-cycle. The beams are attached to each other using leaf springs. So that it can be stretched in its plane, the grating is free standing. One of the challenges is to make a MEMS grating that has a high diffraction efficiency. A grating with a square profile is the easiest structure to manufacture but has only about 40% diffraction efficiency in the first order. In contrast, blazed gratings can have efficiencies close to unity. In order to achieve this, the gratings have been blazed using anisotropic The spectral response of the MEMS grating was measured using an optical spectrum analyser and a collimated white light source in a configuration shown in Figure 2. The optical system is extremely compact. The resulting spectra are shown for different drive voltages in Figure 3. A tuning range of 3% and subnanometer linewidths have been achieved. Potentially 10% is achievable with the improved mechanical design. The spectral response can be better appreciated in Figure 4 taken for a 1.5 mm long fixed grating made with the same MEMS process technology. A 25 db rejection has been achieved experimentally. Efficiency (Normalized) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 1505 1510 1515 1520 1525 1530 1535 Wavelength (nm) Figure 3: The spectral response of the MEMS grating shown in Figure 1 for several different drive voltages ranging from 0 to 55 volts. A unique property of these MEMS gratings is that the efficiency of the gratings is high at all wavelengths. Although, the efficiency is strongly angular dependence, as the angle is never varied, in contrast to standard scanning monochromator, it remains constant. This means that the same device can be used for a wide range of spectral regions from the UV to the mid-ir. This versatility is very promising for 0V 5V 10V 15V 20V 25V 30V 35V 40V 45V 50V 55V 19

spectrometer applications so CSEM has targeted to miniature monochromators as a demonstrator of this technology. The next stage of this work will be to move towards a fully packaged compact spectrometer. The near-ir has been chosen to demonstrate the technology, although main potential applications are excepted to be in the mid IR. Several challenges remain, such as increasing the tuning range, control of stray light, etc. In addition all the system related issues such as drive electronics and the mechanical housing need to be finalized. 1.0 Measured (Normalized) 0.8 Theory NA = 0.0011 0.6 0.4 0.2 0.0 810 812 814 816 818 820 822 824 Wavelength (nm) Figure 4: Optical characterization and simulation. Optical characterization has proven the expected high optical performance: a linewidth of 0.4 nm at 800 nm has been demonstrated for a 1.5 mm long blazed grating. The MEMS gratings can also be used as the tuning element for external cavity lasers. They have many advantages over standard gratings because the mechanics to tune the grating is built-in so the total module can be compact, rapid and eventually low cost. The gratings are currently being tested with external cavity tunable Quantum Cascade Lasers [5]. A success here will lead to the very compact tunable Mid-IR source. CSEM thanks NCCR Quantum Photonics that partly funded this work. [1] H. Schenk, et al., Photonic microsystems: an enabling technology for light deflection and modulation, SPIE, vol.5348, Nr 1, (2004), 7-21 [2] www.siliconlight.com [3] www.polychromix.com/html/products.htm [4] M. Tormen, et al., Deformable MEMS grating for wide tunability and high operating speed, SPIE, vol. 6114, (2006), 61140C [5] C. Sirtori, J. Faist, F. Capasso, The quantum cascade laser. A device based on two-dimensional electronic subbands, Pure and Applied Optics, vol. 7, Nr. 2, (March 1998), 373-81 20

Solar Islands A Novel Approach to Cost Efficient Solar Power Plants T. Hinderling, Y. Allani, M. Wannemacher, U. Elsasser Existing Solar Power Plants are too small, need complex constructions and drive systems to follow the sun s altitude and have a limited use factor of the area. Therefore the generated energy is too expensive. The target of the new concept Solar Islands is to improve all these cost factors and to end up with a cost per kwh which is competitive with today s energy costs. Furthermore the design as a floating island allows not only the application on land, but also on lakes, lagoons or on high seas. The vision is to build very large islands, floating on the pacific, that could contribute 1/4 th of the estimated global energy demand in 2030. electrical energy in a conventional steam turbine generator. The heat can be stored by using latent storage materials like liquid salt in order to extend delivery of electric energy in the evening hours. The generation of sustainable energy will become one of the main challenges of our civilization for the coming decades. Worldwide energy demand is expected to grow from about 10 GTep (Giga Ton Equivalent Petrol) in the beginning of the century to 15-20 GTep by 2050. Among the many renewable energy sources, the potential of solar energy is at least one hundred times larger than any other renewable energy source. Today, there are four main classes of solar energy systems in operation or in development: Photovoltaic panels (PV) Low temperature solar panels (collectors) Thermo-solar high temperature panels and systems (100-350 C) also known as Concentrated Solar Power (CSP) and higher temperature (800-1000 C), e.g. solar tower As costs for PV panels are still quite high, efficiency of the energy conversion is quite low, and storage of produced energy has not been solved, this technology is not appropriate for bulk energy supply. Low temperature panels are only useful for warm water supply for domestic and industrial use. Therefore only CSP is a promising candidate for large scale application. As a lower cost alternative, Solar Islands will use extra flat concentrators, built out of flat mirror glass blades which form a Fresnel reflector, see Figure 1. The concentrators will not follow the elevation of the sun, but its azimuth. To this end, the concentrators are mounted flat on the platform. Thus all elements of the platform will be passive, only the platform itself will rotate in order to follow the azimuth. Figure 2: Floating Platform The platform will consist of an outer torus (e.g. steel ring). The inner part is covered with a low-cost surface sheet (e.g. plastic foil). An overpressure is applied below this membrane, thus exerting a vertical force equal to the weight of the solar thermal modules placed on the membrane, as depicted in Figure 2. Only about 5 mbar overpressure is needed to carry a load of 50 kg/m 2. This novel design enables a simple turning of the platform by using electric hydrodynamic motors. Figure 3: Large Islands on open sea (computer graphic) The same principle can be applied for land based platforms, where the outer ring is simply swimming in a circular water trench. In that case, drive wheels will be used for the island s propulsion. Figure 1: Extra-Flat Concentrator (EFC) Most of the currently build and planned CSP power plants [1] make use of parabolic trough-shaped mirror reflectors, that concentrate sunlight to receiver tubes placed in the trough s focal line. The tube contains a heat exchange fluid or direct steam generation (DSG) is used. The steam is converted to Figure 4: Cross-section of land based Solar Island (computer graphic) 21

As a first step, CSEM is building such a land based prototype in the emirate Ras Al-Khaimah (RAK) with a diameter of 86 m, see Figure 5. This island will be equipped with 68 solar thermal modules, each of size 8 m x 8 m. The modules and the entire thermal loop is designed and manufactured by the CSEM startup Nolaris. At the centre of the island the feeding water will be supplied by a pivotable joint. From there, the water will be distributed to the modules. All modules of a row form one branch of this network. The branches are in fact the absorber tubes, which are mounted 4 m above the mirror blades. In a coaxial manner, the feeding water floats through an inner pipe to the end of the branch. Figure 8 shows the basic principles of the absorber tube. Figure 5: Prototype of diameter 86m (CAD Model) The outer ring is designed as a torus of 2 m height, made out of 6 mm thick steel. Figure 6 shows the first produced segments. Figure 8: Design of absorber tube The water will arrive preheated at the end of the branch and will flow at this point to the outer pipe (Figure 9). On its way back to the central tube, the water will heat up further and will be transformed into steam. The steam will leave the island through a pivotable joint and will drive a steam turbine which is placed next to the island. Figure 6: Steel torus elements A simple polyolefin foil of 2 mm thickness, enforced with some polyester fibers, will be clamped to the torus and span the entire inner part of the island. Spacing elements will be arranged in linear rows in order to distribute the load of the modules to the foils. Additionally, steel cables will be spanned over the island in a 4 m x 4 m grid to stabilize the modules and transmit horizontal wind forces to the torus. Intensive FEM and wind simulations have been made to assure the utmost stable orientation of the modules, see Figure 7. Figure 9: Water and steam network The generated peak power of the prototype will amount to approx. 1 MW, with an average power of 250 kw. The annual energy production is expected to reach 2.2 GWh. Nolaris SA, a CSEM Start-up Independent mechanical designer, consultant to CSEM [1] F. Trieb, H. Müller-Steinhagen, Sustainable Electricity and Water for Europe, Middle East and North Africa, DESERTEC, Whitebook of TREC and Club of Rome (2007). Figure 7: Part of the CAD model (absorber tubes not shown) 22

MICROELECTRONICS Christian Enz The research activities conducted in the field of Integrated Systems for Information Technology (ISIT) are focused on the design of highly integrated systems targeting low-power and low-voltage applications. The latter systems typically include complex microelectronics Systems-on-Chip (SoCs), embedding many functionalities on a single chip, together with other heterogeneous devices such as RF passives, resonators and filters, silicon time basis and sensors into advanced Systems-in-Package (SiPs). The research is organized around four different generic technology platforms: Digital SoC platform Sensory Information Processing platform Integrated RF Circuits and Systems platform RF and Piezoelectric Components platform. The achievements made during 2007 in these different platforms are discussed in more detail below. The Digital SoC platform aims at developing all the key digital components required in a SoC, including low-leakage memories and highly energy-efficient processors. The latter include the Macgic, a 4 MAC digital signal processor (DSP) developed for intensive digital signal processing and the icyflex, a 32-bit microcontroller core with additional DSP capabilities, for simple signal processing. These processors have now reached a certain degree of maturity and have started to be integrated in several industrial SoCs. As an example, four Macgic DSPs have successfully been used in a programmable multi-processor engine for an ultra low-power mobile digital TV. The icyflex has now become the heart of all CSEM SoCs replacing the long-time used 8-bits CoolRISC microcontroller. It is also used in the new generation of digital vision sensors SoC called icycam. The Sensory Information Processing platform implements powerful vision systems that are able to extract essential image features in real-time and at low-power. These features include the three most important information categories that are used by the basic operation of the human vision, namely, the contrast (intensity variation), the direction of contrast (feature orientation) and the motion (spatio-temporal contrast variation). The new vision sensor platform has been migrated from the former 0.5 µm CMOS process towards a 0.18 µm process. In the former version, the contrast extraction and calculation was fully done in the analog domain, making it difficult to migrate. In order to take full advantage of technology scaling, the core of the vision sensor architecture has been profoundly modified and is now essentially digital. This also allows taking advantage of the icyflex processor in the newly designed icycam vision sensor SoC. The ability of vision sensors to process the image feature locally enables it to be used together with other vision sensors connected together with a rather low data rate wireless channel. Such a network allows performing data fusion of signals provided by several vision sensors and 3D cameras in order to track persons in buildings. Another SoC including the icyflex is used for nanometric absolute position encoding. Such miniaturized optical encoders have a great potential for applications in robotics, automation and machine tools. The Integrated RF Circuits and Systems platform mainly targets ultra low-power short-range and low data rate applications. A new development platform has been engineered for the design of narrow-band RF transceivers operating in the 868 MHz and 915 MHz ISM bands. It includes an integrated front-end IC with a low-if super-heterodyne receiver architecture and a newly designed direct modulation RF transmitter. The on-chip analog baseband uses a phaseto-digital converter and is followed by a digital baseband implemented in a FPGA in order to keep a maximum of flexibility. This platform allows experimenting on different modulation schemes. The efficient combination of MEMS such as BAW resonators and ICs has always been a strong research topic in the field of ultra low-power radio design. After having realized a BAW RF front-end, the BAW is also used in the frequency synthesizer. A new architecture is proposed to take advantage of the low-phase noise but circumvent the limited frequency tuning range of the BAW VCO. It uses a quasi-harmonic relaxation oscillator featuring a large tuning range compensating the limited one of the RF VCO. This architecture is similar to the one used in the radio that will be used within the PackTime MIP. The new radio and synthesizer architectures mentioned above rely heavily on the BAW and silicon resonators developed in the RF and Piezoelectric Components platform. These devices take advantage of the AlN thin film piezo-electric technology available at CSEM. Silicon MEMS resonators can potentially achieve similar performance to crystal quartz with a smaller size. However, they suffer from the high temperature coefficient of silicon and imperatively have to be compensated in temperature. This can be done electronically by using an on-chip temperature sensor or by depositing an additional layer of proper thickness made of SiO2 having a positive temperature coefficient. Two families of Si-resonators have been developed: temperature compensated 20 to 140 KHz flexural resonators and high-q 1 MHz extensional resonators. These MEMS are activated thanks to an AlN piezoelectric layer, making them compatible with the voltages used in SoCs. The four technology platforms are evolving towards ever more complex systems combining the different technologies. In this sense there is clearly a convergence of the overall research activity in this field. This concentration should help to solve the important challenges that lie ahead. Among those we can mention the migration towards ultra deep sub-micron CMOS process, with its inherent leakage and parameter variability issues. Also, the packaging remains the main issue for combining MEMS and SoC together for new low-power and ultra miniaturized systems. It is the believe of CSEM that the Integrated Systems for Information Technology platform is well armed to face and solve these important challenges! 23

Data Fusion for Wireless Distributed Tracking Systems F. Rampogna, P.-A. Beuchat, A. Brenzikofer, D. Beyeler, E. Franzi, E. Grenet, A. Hutter, P. Nussbaum, L. Von Allmen The objective of this work is to perform the fusion of data gathered from distributed movement tracking 2D/3D camera nodes and to provide the user with a unified and synthetic view of the activity in the area being monitored. The data communication between the various embedded slave tracking nodes and the master node is performed either through a low-power, low-data-rate, 2.4 GHz RF ad-hoc network, using a portion of the IEEE8102.15.4 TDMA protocol, or through an emulation of the radio network over a wired ethernet link, for test and debug purposes. The work in this project has been done within the RISE multidisciplinary project framework [1]. Both the 2D/3D tracking camera node, and the master node are implemented using CSEM DEVISE cameras [2]. They are based on a 500 MHz BF533 DSP/MCU, and implement 32 MiBytes SDRAM, 2 MiBytes FLASH memory, a 2.4 GHz RF transceiver, a 100 Mbit/s ethernet interface, and a TCP/IP protocol stack developed in-house. The 2D camera nodes use CSEM vision sensors [3], and the 3D camera nodes, MESA s 3D imagers [4]. the feet of the tracked object, first to a local metric coordinates space, and then, to a unified metric room coordinates space. In order to cover a large floor-level area, very wide angle lenses are typically used in 2D camera nodes. These lenses greatly distort the image and therefore a geometric correction is required in order to perform an accurate floor-level projection of the positions of tracked objects. Once the coordinates of all the objects being tracked by all the nodes have been unified, a data fusion algorithm groups together the objects which are spatially close-enough, and associates to them extended properties, such as their kind: U, H, G1 to Gn. If 3D camera nodes are used for the monitoring, the height of tracked objects will also be displayed. Camera node #1 (2D) Camera node #2 (2D) Camera node #3 (2D) Camera node #4 (3D) 1 2 3 4 Figure 1: Principles of data fusion using three 2D camera nodes Figure 1 shows an example of a room being monitored. Various people are present in the room, some are seated, others are walking, and others are discussing while standing still. Three 2D tracking nodes are installed at the ceiling level and are looking down. They have three different orientations: node 1 is oriented towards the west, node 2 towards the north and node 3 towards the east. They all have the same fish-eye optical characteristics. Each camera node detects the presence and tracks the movement of objects in its own field of view (FOV). For each tracked object in the FOV, the following nature of each object is extracted: Unknown (U): the object characteristics are such that it is impossible to determine what kind of object is detected Human (H): the presence of a person has been detected Group (GN): the presence of two or more people has been detected By knowing both the spatial location, optical characteristics, orientation and height of each camera node, it is possible to project the pixel coordinates corresponding to the position of Unified coordinates view of detected objects Synthetic view after data fusion Figure 2: Example of monitored room (CSEM main entrance) Figure 2 illustrates an example of data fusion obtained from the monitoring of the CSEM s main building entrance, where one person is currently leaving the building. The contrast edge images as seen by the three 2D vision sensor nodes and the image heights seen by the 3D camera node are displayed. The unified coordinates representation of the objects seen by the various camera nodes is shown at the bottom left, together with their respective trajectories and the representation of the cameras FOV. The synthetic representation of the objects tracked by the cameras after data fusion is shown at the bottom right, together with the location and orientation of the various camera nodes. [1] A. Hutter, et al., RISE The Rich Sensing Concept, in this report, page 15 [2] www.csem-devise.com [3] www.csem-devise.com/vision-md535v2a1-413-09-06.pdf [4] www.mesa-imaging.ch 24

High Dynamic Range Versatile Front-End for Vision Systems P. Heim, F. Kaess, P.-F. Rüedi A 128 by 152 pixel array with very high intra-scene dynamic range has been integrated in a 0.18 µm optical process. It features a data representation which encodes nearly 7 decades of illumination with a 10 bit data word. Furthermore, the data representation used facilitates subsequent data processing such as contrast computation. There is an increasing need for optical sensors optimally suited for systems whose purpose is not to restitute an image to a final user, but to analyze the content of a visual scene and make a decision. The main requirements for such a sensor are a wide intra-scene dynamic range and a data representation facilitating processing. Standard image sensors have a too narrow dynamic range to cope with the tremendous change of illumination occurring in natural visual scenes. Logarithmic imagers offer a wide dynamic range and a data representation which easily discard illumination changes in an image. However, up to now, the logarithmic compression has been performed in the analog domain, bringing a high pixel-to-pixel fixed pattern noise, which makes them unusable for commercial applications. The visual front-end developed at CSEM circumvents this issue. It incorporates a high dynamic range pixel array with logarithmic compression in the digital domain to avoid the large fixed pattern noise associated with analog compression. Figure 1 shows a block diagram of a pixel and the logarithmic time generator. Each pixel integrates the photocurrent delivered by a photodiode on a capacitor. The resulting voltage is continuously compared to a reference voltage (VREF). Once VREF is reached, the content of a 10-bit digital word distributed to all pixels in parallel is stored in the pixel memory. This digital word evolves over time to code the logarithm of the time elapsed since the beginning of the integration. Once photo-current integration is terminated, the 10-bit words stored in the pixel array are read-out. Figure 2: Micrograph of the circuit The left of Figure 3 shows an image acquired with the sensor. Notice that the face of the person and the outside background are simultaneously visible, illustrating the high dynamic range. The right of Figure 3 shows the contrast representation obtained by simply computing the difference between neighboring pixels. Notice the independence on the illumination level. Figure 3: High dynamic range visual scene Figure 1: Block diagram of the pixel and logarithmic time generator The data representation delivered by the sensor enables to easily discard illumination and compute the contrast between neighbouring pixels. The circuit encompasses an array of 128 by 152 pixels, with a pixel pitch of 14 µm and a fill factor of 20% in a 0.18 µm optical process. Figure 2 shows a microphotograph of the circuit. A system-on-chip [1] incorporating a 320 by 240 (QVGA) pixel array based on this principle, an icyflex [2] processor, RAM and communication interfaces is now in the process of being integrated. It will enable vision applications (image capture and processing) to be performed on a single chip. [1] C. Arm, et al., icycam, a System-On-Chip (SoC) for Vision Applications, in this report, page 30 [2] M. Morgan, et al., icyflex, a Low Power 32-bit Microcontroller Core, CSEM Scientific and Technical Report 2006, page 20 25

A High-Performance 2.4 GHz RF Front-End in a 90 nm Process M. Kucera, N. Scolari, F. Pengg, P. Persechini, D. Ruffieux, A. Vouilloz, E. Vardarli, P. Ferrat, J. Chabloz, R. Caseiro, C. Monneron The ever ongoing advances in semiconductor manufacturing and the continuous shrink of the integrated transistors pose new challenges and require innovative solutions for the design of high-performance and low-power RF circuits in the ultra-deep submicron range. This paper provides insight in the design of a high performance 2.4 GHz RF front-end in 90 nm CMOS. The well known Moore s Law has been valid for nearly 40 years, confirming that integrated circuit (IC) technology evolves every 18 months with a new process generation that enables higher circuit integration and reduced IC size and cost. While the main driving forces are large digital ICs, analog and RF circuits can also benefit from these technology advances, in particular system-on-chip (SoC) realizations where they are embedded jointly with large digital sections (e.g. mobile telephony ICs). Concerning radio SoCs, the co-integration of highperformance low-power RF circuits together with digital blocks has been proven using submicron CMOS (0.5µm - 0.18µm) [1]. RF-platforms of the next generation, such as Software Defined Radios (SDR), rely heavily on large digital processing blocks [2], which pleads for using ultra-deep submicron (UDSM) CMOS (90 nm and beyond). The challenge today thus consists of the design of highperformance RF circuits with competitive sizes of the RF blocks (UDSM CMOS being expensive) and with low power consumption, which is critical for portable, battery operated applications targeted by CSEM. Within this context, CSEM has designed a 90 nm CMOS RF front-end circuit with the following goals: To achieve high-performance specifications with lowest possible power consumption while minimizing the required silicon area. To design in a standard digital 90 nm CMOS process, without relying on costly RF/analog processing options: this is mandatory for enabling seamless co-integration with digital circuits. To establish a library of optimized RF passive devices: the generic RF passive devices (inductors, capacitors, varicaps, etc) provided by silicon foundries usually have inadequate performance and prohibitive sizes, or require additional processing options. The design of optimized passives on the standard digital technology is crucial for achieving best-in-class RF performance. The RF front-end targets the 2.4 GHz ISM band, and includes a receiver front-end (LNA, down-conversion mixers), a transmitter front-end (PA, up-conversion mixers), and the critical blocks of the frequency synthesizer (RF VCO, LO buffers, pre-scalers and multi-modulus dividers). The target specifications are a noise figure of 2 db for the receiver frontend with high linearity (IIP3 up to -13 dbm for an entire receiver), and a current consumption of 8 ma from a 1.6 V supply. The transmitter targets +27 dbm of output power which requires the handling of about 1 W and 500 ma on-chip. The layout of the RF front-end IC is shown in Figure 1. Figure 1: Layout of the 2.4 GHz RF front end in 90nm CMOS As mentioned above, special care was taken in the design and modelling of dedicated passives using the methodology developed at CSEM [3]. A close-up view of one of the RF inductors together with its RF test-fixture is given in Figure 2. An inductance value of 12 nh and a quality factor Q better than 10 at 2.4 GHz are expected. It occupies a surface of 200x200 µm 2 (in the foundry design kit, no inductances were available without using RF options and limited metal layers). Figure 2: Layout of an inductor in 90nm (right) with the pad structure for the device measurement on the RF prober (left) The 2.4GHz RF front-end presented in this paper is currently in fabrication and samples for characterization are expected shortly. [1] V. Peiris, et al., A 1V 433/868MHz 25kb/s-FSK 2kb/s-OOK RF Transceiver SoC in Standard Digital 0.18 μm CMOS, in Int. Solid-State Circ. Conf. Dig. of Tech. Papers, Feb. 2005, 258 259. [2] E. Le Roux, Low Power Flexible Digital Demodulator for Integrated RF Transceiver, CSEM Scientific and Technical Report 2006, page 27 [3] F. Giroud, et al., Integrated Inductors in 0.18 μm CMOS and Model-Fitting Approach for Low-power 2.45GHz RF blocks, CSEM Scientific and Technical Report 2005, page 23 26

Direct Modulation RF Transmitter and Super-Heterodyne Low-IF Receiver Development Platform for 868 MHz and 915 MHz ISM Bands M. Contaldo, E. Le Roux, D. Ruffieux, P. Volet, M. Kucera, N. Raemy, F. Giroud, F. Pengg, S. Gyger, C. Arm, P. Heim, F. Kaess, V. Peiris This paper presents the design of a radio development platform suited for developing ultra low-power high-performance narrow-band RF transceivers. In particular, this platform will be used for validating an 868 MHz/915 MHz RF IC featuring up to ±200kHz modulation bandwidth for different constant-envelope modulation schemes, and consuming below 3 ma current in receive mode under a very-low 1 V supply. For wireless sensor networks or body-area networks for biomedical and lifestyle applications, the need of a miniature and ultra-low power radio transceiver is mandatory to achieve multi-year autonomy with un-obtrusive embodiment. Ultra low-power consumption (below 3 ma under 1 V supply in receive mode) has been demonstrated for radios operating in sub-ghz bands and using simple FSK/OOK modulation schemes [1]. On the other hand, the requirements in terms of modulation schemes and bandwidths happen to differ significantly depending on the targeted applications. The design of an optimal radio architecture remains thus a complex task as the impact and the added value of various modulation strategies must be quantified carefully before final integration, in particular for low-power radios. Although high- and low-level simulations help for preliminary validation, a given radio architecture may be fully validated only with real-world measurements including complex channel and interference situations which are difficult to simulate. To address this issue, this paper presents an intermediate approach, in the form of a microelectronics-oriented hardware development platform, as depicted in Figure 1. analog sub-block bias settings, the configuration is done through serial link (I2C). For fast digital signal, i.e. the RF synthesizer settings, the configuration is done through a parallel bus. The FPGA clock signal is generated on the RF front-end IC, therefore their association does not need any additional circuit. Within the RF front-end IC, the transmitter is based on a direct modulation architecture. The frequency synthesizer is implemented by means of a fractional-n PLL employing a 3 rd order MASH sigma delta modulator, taking advantage of its beneficial noise shaping effect. The external loop filter and the programmable charge pump permit a good customizability of the synthesizer performances. The synthesized signal is then directly coupled to the power amplifier and directed to a SAW filter, before reaching the antenna. The receiver is based on a heterodyne low-if architecture that down-converts the RF signal into at 96-103 MHz intermediate frequency and then to 75-150 khz, where it can be filtered. The signal is then converted in the digital domain using an integrated phase-adc whose output drives the FPGA to allow the design and measurement of different demodulations [2] The main specifications of the radio are up to ±200 khz modulation bandwidth, with a 3 ma current consumption in Rx for -105 dbm sensitivity, and 40 ma in Tx for a 10 dbm output power, under 1V supply. A photograph of the RF front-end IC, integrated in 0.18um CMOS, is given in Figure 2. Figure 1: Development platform block diagram This approach with a programmable FPGA-based back-end enables the development and validation of various modulation schemes with a high degree of flexibility, by programming baseband processing algorithms into the FPGA, and characterizing the link performance before full integration. Because the front-end is a low-power RF IC, the architecture of the platform is very close to that of an integrated circuit. Hence the design of a complete transceiver combining both sections on a single die will be enabled with a low risk level. The RF front-end IC includes the transmitter (Tx), receiver (Rx) and frequency synthesizer (PLL) circuitry, from the antenna input towards the analog baseband, without relying on any other external active components. The Rx/Tx is designed for operation in the 868/915 MHz bands. The FPGA embeds the digital parts such as the modulation/demodulation section of the radio, the control for the RF front-end IC and the interfaces. For the slow digital configuration signals, e.g. Figure 2: Microphotograph of the RF front-end IC [1] V. Peiris, et al., A 1V 433/868MHz 25kb/s-FSK 2kb/s-OOK RF Transceiver SoC in Standard Digital 0.18 μm CMOS, in Int. Solid-State Circ. Conf. Dig. of Tech. Papers, Feb. 2005, 258-259 [2] E. Le Roux, Low Power Flexible Digital Demodulator for Integrated RF Transceiver, CSEM Scientific and Technical Report 2006, page 27 27

Quasi-Harmonic Quadrature CMOS Relaxation Oscillator J. Chabloz, D. Ruffieux In this paper, a solution to realize a local oscillator (LO) for a low power super-heterodyne receiver is presented. The complete local frequency synthesis solution comprises a fixed-frequency bulk-acoustic wave (BAW) RF oscillator with low phase noise and low tuning range. A quasi-harmonic quadrature relaxation oscillator with a large tuning range is realized and can be used to compensate for variations in the RF oscillator as well as to cover the entire bandwidth for multiple channel selection. The receiver for which the presented oscillator is specifically designed is based on a super-heterodyne architecture and its block schematic is described in Figure 1. The receiver frontend and baseband parts have already been integrated and characterized with external oscillators [1]. A BAW oscillator embedded within a digital frequency synthesis [2] is used as a first local source (BAW RF LO) and runs at a fixed frequency, determined by the physical dimensions of the BAW resonator. The second downconversion uses a quadrature relaxation oscillator (IF LO) with a large tuning range [3] that is presented below. The presented circuit has been fabricated in a standard 0.18 µm CMOS process. Figure 3 shows the actual receiver test chip photograph. The BAW resonator is bonded together with the chip. On-chip Passband Balun BAW Filter IF Amplifier LNA 2400.0-2483.5 MHz 2330.0 MHz fixed BAW LO Quadrature IF Oscill. Frequency Synthesis Figure 1: Super-heterodyne receiver architecture 70.0-153.5 MHz tunable Since the second downconversion is direct, the selected channel frequency is determined by the sum or the difference of both oscillator frequencies. Therefore the allowed frequency excursion on the second oscillator allows to compensate entirely for the lack of tunability of the first one. The proposed quasi-harmonic quadrature relaxation oscillator architecture is described in Figure 2. Coupling transistors are used to couple two classical relaxation oscillator cores. M3 Figure 3: Receiver test chip photograph The oscillation frequency has been measured with different amplitude settings and the results are shown in Figure 4. It can be seen that the tuning range covers the wanted frequencies which range from 70 MHz to 150 MHz. Oscillation frequency [MHz] 150 140 130 120 110 100 90 80 70 60 0 120 140 1 160 2 180 3 200 Relaxation oscillator current consumption (wo buffer) [μa] 4 220 5 240 6 K = 1.35 K = 1.2 Figure 4: Measured oscillator frequency tuning range with two different amplitude settings 260 7 280 Coupling transistors M1 M2 The quadrature coupling principle is verified by measuring an average phase difference of 89 between the I and Q signals. Spot phase noises of -104 dbc/hz at 1 MHz offset and -111 dbc/hz at 3 MHz offset have been measured. Figure 2: Quadrature oscillator architecture The wide variation of bias current needed to tune the oscillation frequency over the required range also creates wide variations in the oscillator operating point, more specifically in the steady-state oscillation amplitude. In order to increase the tuning range, linearize the current-to-frequency characteristic and allow the oscillator to stay in the quasiharmonic mode over the entire range, an amplitude control has been designed. [1] J. Chabloz, et al., A Low-Power 2.4GHz CMOS Front-End using BAW Resonators, ISSCC 06 proceedings, 1244-1253 [2] D. Ruffieux, et al., An Agile 2.4GHz MEMS-Based Digital Frequency Synthesizer, CSEM Scientific and Technical Report 2006, page 24 [3] J. Chabloz, et al., Frequency Synthesis for a Low-Power 2.4GHz Receiver using a BAW Oscillator and a Relaxation Oscillator, ESSCIRC 07 proceedings, 492-495 28

Silicon Resonators: Thermal Compensation and Q Factor Optimization J. Baborowski, A.Pezous, C. Muller, Y. Welte, M.-A. Dubois The feasibility of two families of AlN/Si resonators has been demonstrated. The resonating structure is obtained with silicon suspended beams driven by an AlN piezoelectric layer. The flexural resonators exhibit extremely low thermal drift of resonance frequency (α close to zero). The thermal compensation has been obtained at device-level by using SiO2 with an appropriate thickness. The extensional resonators exhibit a Q factor larger than 140 000 below 1 mbar and a coupling coefficient of 0.05%. High Q silicon MEMS resonators have great potential for onchip high frequency synthesis, integrated circuit clock generation, and other applications based on a stable frequency reference signal. The thermal compensation of the silicon resonators as well as the development of miniature inexpensive lead-free packaging solutions, represent however real technical and scientific challenges. vacuum as high as 140000, a coupling factor k 2 eff of 0.05%, a motional resistance below 200 Ohm and a mainly linear TCf of -28.5 ppm/ C. The tolerance of the resonance frequency over 100 mm wafer is lower than 0.1%. CSEM SA has demonstrated the feasibility of two types of AlN/Si resonators [1] : Thermally compensated, 20 khz to 140 khz flexural outof-plane mode resonator, High Q, 1 MHz extensional in-plane mode resonator. Both types of resonators are currently being implemented in the 2.4 GHz MEMS-based ULP transceiver. Figure 2: FEM simulation of the energy distribution in tuning fork Hermetic packaging at low pressure is one of the largest barriers to commercialisation of MEMS timing reference. In this project the solutions for packaging the backside of the resonator have been demonstrated. The first solution consists in the fabrication of buried cavities within the SOI wafer, followed by the building of the piezoelectric resonator directly on the membrane. The second solution uses a capping wafer (thin silicon or Pyrex) sealed by low temperature fusion bonding or by anodic bonding [2]. Figure 1: Top view of 32kHz silicon resonator with AlN actuation The triple tuning fork out-of-plane resonator (Figure 1) presents a zero first order Thermal Coefficient of frequency (α TCf) that has been obtained at the device level by balancing the negative Thermal Coefficient of Elasticity (TCE) of Si and AlN with the positive TCE of SiO2. The frequency stability over a temperature range from 0 to +60 C is better than 20 ppm at 70 khz. The possibility of fine tuning the TCf by trimming the thickness of SiO2 has been shown, as well as the ability to adjust the resonance frequency by applying a DC bias, with a sensitivity of 0.3 ppm/v. Finite element modelling has been used to analyze the distribution of energy in the tuning fork. It has been shown that the clamping conditions between the vibrating arms and bulk substrate are the major source of energy loss (Figure 2). A new design has been realized to reduce this energy leakage and hence increase the Q factor. In the case of the 1MHz extensional mode resonators, the effect of air pressure has been measured. In order to obtain stable values of Q factors higher than 100000 it is mandatory to maintain the resonator at a pressure below 1 mbar (Figure 3). This type of resonator exhibits a Q factor in Figure 3: Variation of Q factor as function of pressure for 1MHz extensional resonator [1] J. Baborowski, C. Bourgeois, A. Pezous, C. Muller, M.-A. Dubois, Piezoelectrically Activated Silicon Resonators, Proceedings of the Joint 2007 European Frequency and Time Forum & 2007 IEEE Frequency Control Symposium, 1210-1213 [2] D. Ruffieux, et al., PackTime Zero-Level Packaging of Silicon Time-base, in this report, page 16 29

icycam, a System-On Chip (SoC) for Vision Applications C. Arm, R. Caseiro, S. Gyger, P. Heim, F. Kaess, J.-L. Nagel, P.-F. Rüedi, S. Todeschini Icycam is a circuit combining on the same chip a 32-bit icyflex [1] processor operated at 50 MIPS, and a high dynamic range versatile pixel array, integrated on a 0.18 μm optical process. It enables the implementation on a single chip of image capture and processing, thus bringing considerable advantages in terms of cost, size and power consumption. There is a high demand for low cost and low power vision systems able to perform real-time analysis of a visual scene. Merging on a single chip a pixel array to capture an image and a processor to analyze it offers interesting perspectives in terms of cost and power consumption reduction. Icycam has been developed to address vision tasks in fields such as surveillance, automotive, optical character recognition and industrial control. It incorporates a high dynamic range pixel array [2], an icyflex [1] processor, RAM and digital peripherals to enable a maximum of flexibility. It can be programmed in assembler or C code to implement vision algorithms and controlling tasks. The icycam chip architecture is illustrated on Figure 1 and detailed in the following sections. RAM 128 KiBytes SPI1 SPI2 320 x 240 (QVGA) high dynamic range versatile pixel array Sensor interface GPIO 64 PPI Figure 1: icycam chip architecture SDRAM GPU icyflex UART JTAG The heart of the system is the 32-bit icyflex processor clocked at a 50 MHz frequency. It communicates with the pixel array, the on-chip SRAM and peripherals via a 64-bit internal data bus. The pixel array has a resolution of 320 by 240 pixels (QVGA), with a pixel pitch of 14 µm. Its digital-domain pixel-level logarithmic compression makes it a low noise logarithmic sensor with close to 7 decades of intra-scene dynamic range encoded on a 10-bit data word. Two special purpose interfaces are implemented to pre-process the data flow coming out from the pixel array. The first one is a column-level 16-bit accumulator allowing to sum a row of pixels in one clock cycle, for example to average a group of rows for 1-D applications. The second one is able to extract on the fly the local contrast direction and magnitude (relative change of illumination between neighbouring pixels) when data is transferred from the pixel array to the memory. Thus it offers a data representation facilitating image analysis, without the overhead in terms of processing time. Data transfer between the pixel array and memory or peripherals is performed by a group of 4 (10 bits per pixel) or a 8 (8 bits per pixel) pixels in parallel at system clock rate. This image data can be processed with the icyflex s Data Processing Unit (DPU) which has been complemented with a Graphical Processing Unit (GPU) tailored for vision algorithms, able to perform simple arithmetical operations on 8- or 16-bit data grouped in a 64-bit word. Internal SRAM being size consuming, the internal data and program memory space is limited to 128 KiBytes. This memory range can be extended with an external SDRAM up to 32 MiBytes. The whole memory space is unified which means it is accessible via the data, program and DMA busses. An internal DMA working on 8/16/32 and 64 bits enables transfers from/to the vision sensor, memories and peripherals with data packing and unpacking features. The DMA has a 2 dimensional transfer mode for the source as well as the destination addresses which is a prerequisite for vision applications. A parallel peripheral interface (PPI) is incorporated to enable data transfer to an external DSP for vision applications requiring more processing power than that available on-chip. This PPI port also enables the coupling of an external sensor, such as a high resolution colour imager, to icycam. To further improve flexibility and ease of use, SPI, UART, GPIO and JTAG interfaces are also implemented on icycam. This wide range of interfaces makes icycam a truly versatile circuit. When the limited amount of on-chip memory and processing power is sufficient, it can be used as a single chip solution. When a high amount of data has to be processed it can be used with an external memory. Finally, if a high processing power is required, it can be used as a sensor connected to an external DSP. The chip is in the process of being integrated in a 0.18 µm optical technology. It incorporates all the necessary test hardware in order to be easily testable in production. [1] M. Morgan, et al., icyflex A Low Power 32-bit Microcontroller Core, CSEM Scientific and Technical Report 2006, page 20 [2] P. Heim, et al., High dynamic range versatile front-end for vision systems, in this report, page 25 30

Programmable Multi-Processor Engine for Ultra-Low-Power Single-Chip DVB Receiver C. Arm, P.-D. Pfister, F. Rampogna, Ch. Ruppert, A. Duret A family of System-On-Chip (SoC) circuits implementing terrestrial mobile digital TV (DVB-T/H) receivers as single-die solutions requiring very few external components has been developed and is being produced by the industrial partner of this project. The use of ultra-low-power programmable DSPs for the implementation of the Orthogonal Frequency Division Multiplex (OFDM) demodulation and adaptive channel estimation/correction allows an automatic adaptation of the receiver to the fast-changing reception conditions encountered in mobile receivers CSEM is participating in a CTI/KTI project whose goal is to develop modem core intellectual property (IP) supporting multiple broadband wireless OFDM modulations (DAB, DVB, T-DMB, MediaFlo, etc.). The core is architectured as a software defined radio implementing a multiprocessor architecture based on CSEM Macgic DSP core [1]. The final goal for the industrial partner [2] of this project is the production of a family of low-cost, low voltage, ultra-low power single-die digital television receivers in advanced CMOS technologies (90 nm and smaller geometries). The first member of this family is the AS-101, which targets the following ETSI [3] standards: DVB-T, Digital Video Broadcasting for low-power terrestrial digital television receivers DVB-H, for mobile ultra-low-power multimedia receivers. The low power consumption, of less than 325 mw for DVB-T reception, together with the small footprint, less than 100 mm 2 for a complete module, a very short bill of material, and a choice of standard host interfaces (USB2.0, SDIO, SPI) make them ideal for a very wide range of mobile consumer applications. The structure of the AS-101 DVB receiver chip is shown in Figure 1. The circuit implements a multiband zero intermediate frequency RF-tuner, the reprogrammable OFDM engine made of multiple Macgic DSP cores and hardware accelerators, the channel decoding and the link layer data stream extraction using a standard 32-bit processor core together with error correction hardware accelerators. OFDM demodulation and channel estimation/correction algorithms. New instructions and specific operations have been added; some others, irrelevant to the targeted application, removed from the instruction set, so as to optimise its speed and energy consumption. The software defined radio technology (SDR) architecture, based on the Macgic cores, is a key element of ensuring quality of service. In addition, the flexibility of CSEM programmable technology allows adaptive data processing to therefore guarantee the best performance in all reception conditions. Our innovative DSP based approach provides the flexibility to select the most appropriate algorithm in many circumstances and conditions, and in particular to recover weak signals in a noisy environment or compensate for the Doppler effect. Adaptive channel correction algorithms have been devised and implemented. These algorithms improve the demodulation signal-to-noise ratio and therefore reduce the bit error rate under the most common adverse mobile reception conditions: Multipath: Single-frequency networks where more than one transmitter broadcasts the same stream, and/or multiple electromagnetic obstacles/mirrors such as buildings (and walls/windows when used indoors) that scatter and/or reflect the broadcast signal, may lead to potentially destructive interferences, depending on the spatial location of the receiver. Such interferences can be countered through antenna diversity. Fast changing reception conditions caused by moving receiver or obstacles, which are typical in urban areas. Doppler effect that is caused by fast-moving objects: typically a mobile receiver located in a car/train. Prototypes and demonstrators have been developed and have been available for more than one year. The AS-101 circuit has entered the production stage and has already been licensed to a few customers of the industrial partner. The project partners are Abilis Systems and HEIG-VD [4]. This work was partly funded by the CTI/KTI which CSEM thanks. Figure 1: AS-101 Single-die 90 nm DVB-T/H receiver structure Two other circuits are members of this family of low-power OFDM receivers: the AS-102 limited to the support of the DVB-T standard, and the AS-103 which improves the reception in difficult conditions by allowing antenna (spatial) diversity (use of multiple reception antennas). The CSEM has developed the Macgic DSP architecture. The DSP has been specially tailored and optimized to best suit Abilis Systems [1] F. Rampogna, et al., FPGA Prototyping Platform for the Macgic DSP Cores, CSEM Scientific and Technical Report 2003, page 27 [2] www.abiliss.com [3] www.etsi.org/website/technologies/dvb.aspx [4] www.heig-vd.ch 31

32

PHOTONICS Nicolas Blanc The Photonics Division has over the last few years enjoyed a steady growth in terms of income, number of employees and technologies. To further sustain and reinforce CSEM activity in this domain, major decisions were taken at the end of 2006 with a strong impact on key changes in the Photonics Division. Firstly, the two sections Image Sensing and Optoelectronics Systems moved in September 2007 from the Badenerstrasse to its new site in Technopark Zürich, where CSEM Zurich rents 1 1000 m 2. The completely new and modern infrastructure includes several hundred m 2 of lab space, mostly optical labs with conditioned and filtered air. CSEM Zurich benefits now from a very central location with excellent public transport: Zurich main railway station is within 10 minutes and Zurich airport can be reached within 20 minutes by train. Moreover the new location offers many potential synergies with nearby small- and medium-size companies, including numerous start-ups and high-tech corporations. Secondly, the two sections Micro-optical Systems and Polymer Optoelectronics moved in January 2008 to Basel to build-up a new Division entitled Functional Coatings. This Division is located in the Areal Rosental and will further develop technologies related to passive (e.g. micro-optical elements and optical security devices) as well as active (e.g. polymer light-emitting devices, PLEDs) opto-electronics components and systems, with a focus on organic materials and moulding, embossing, as well as various printing processes. The Functional Coatings Division benefits from important investments including 500 m 2 of fully equipped clean rooms. CSEM presence in Basel is also expected to significantly reinforce its R&D activity, in particular for applications in the domain of Life Science, Chemistry and Pharmaceutics. On the scientific and technical side, the Photonics Division in 2007 kept its focus on the development of optoelectronic components, including PLEDs, micro-optical elements and image sensors, as well as their combination in highly integrated and compact systems. One strategic axis remains with the development of novel devices on the basis of polymer materials which can be very advantageous in terms of costs and for applications requiring large area devices. This is notably achieved thanks to the use of low cost manufacturing processes derived from the printing industry. In this field the material properties and formulation are key to the development and optimization of state-of-the art polymer based optoelectronics components. In order to speed up the screening and formulation of solvent processed organic LEDs, a modified pipetting-robot together with an automated optoelectrical characterization system have been developed. This high-throughput apparatus allows the fabrication and characterization of batches of 49 PLED samples in one experimental run, enabling thus the systematic study of the influence of parameter variations to the overall device performances and providing extensive datasets for material testing, device optimization and device modelling. A concentration sweep of individual blend components can for example quickly reveal the ideal blend ratio for optimum composition. 3D-cameras based on the Time-of-Flight principle are able to provide depth maps of their environment in real-time. Different modulation schemes from continuous wave modulation, pulsed mode and more complex modulations schemes can be used as well. In all cases the 3D camera relies on an active illumination that can be intensity modulated at high frequency. Alternatively the detailed imaging of fast moving objects (> 100 m/s) also calls for flash light illumination. For such applications a new illumination unit has been realized based on multi-mode vertical-cavity surface-emitting laser arrays. This approach reaches modulation frequencies of up to 80 MHz and an optical peak output power of 1.3 Watt. Miniaturization and low-power are two key characteristics of CSEM heritage and these characteristics are reflected in many projects. As an example within the European project MuFly, CSEM has developed a miniaturized and light weight 360 camera module for autonomous micro aerial vehicles. The camera fulfils stringent requirements: a power consumption of less than 1 mw, a weight of less than 5 g and small dimensions of ~2 cm 3, while providing a high dynamic range in excess of 140 db for reliable indoor and outdoor operations under various illumination conditions. A further example of miniaturization is provided in the development of a highly integrated optical linear. The latter is designed to fit in a volume of only 50 mm 3 while providing spatial resolution in the 100 nm range at a speed of up to 5 m/s. This is achieved thanks to a dedicated custom image sensor, a folded telecentric optics manufactured by injection moulding and further SMD components including a LED illumination and passive elements, all components being mounted on one single flexible print. Last but not least CSEM has built up its capability in the testing and qualification of integrated circuits and optical sensors for small volume series. The testing of a circuit is an essential but also quite an expensive step in the production flow of semiconductor devices. Frequently CSEM customers are looking for small volume production of components with very high expectations with respect to quality. A testing environment has thus been set up to support such production verification and qualification in-house ensuring very short qualification time after prototype evaluation. This is part of the new offering of CSEM and in particular the Photonics Division to its partners and customers. 33

Miniaturized 360 -Camera Module for Collision Avoidance P. Ferrat, C. Gimkiewicz, S. Neukom, Y. Zha, A. Brenzikofer, T. Baechler Omni-view cameras for autonomous micro aerial vehicles have to fulfil stringent requirements: low power consumption (< 1 mw), low weight (< 5 g), small dimensions (~ 2 cm 3 ), and a high dynamic range (> 140 db) for reliable indoor and outdoor operations under various illumination conditions. The presented 360 -vision ultra-miniature camera platform (Figure 1) is based on two components: a catadioptric lens system and a dedicated image sensor. The optical system consists of a hyperbolic mirror and an imaging lens (Figure 2). The vertical field of view is +10 to -35. Figure 1: Picture of the complete camera module The CMOS image sensor (Figure 3) provides a polar pixel field with 128 (polar) by 64 (radial) pixels. Since the number of pixels for each circle is constant, the unwrapped panoramic image achieves a constant resolution for all image regions. The whole camera module delivers 40 frames per second and includes an optical image preprocessing for an effortless remapping of the acquired image into undistorted cylindrical coordinates. power the pixel has a linear response, whereas for high optical input power the pixel shows a logarithmic behaviour. The kneepoint between linear and logarithmic behaviour can be set by applying an external voltage to the pin VLOG. Triangulation with omni-view cameras Especially for flying robots, fast object recognition and collision avoidance has to be ensured. Here, the application of an active triangulation system is proposed (Figure 2). A laser module is mounted on top of the omni-view camera. The laser emits a 360 laser plane. The reflections of the laser plane on objects in a room form a distorted circle, where the distortion is a measure for the object distance. Figure 4 shows the calculated distance resolution for objects closer than 3 m. The resolution can be increased by various means if required. The plot in Figure 4 is computed for a distance of the laser to the 0 axis of 150 mm and a laser beam angle of 8 (Figure 4). Figure 4: Distance resolution of the optical sub-system shown in Figure 2. Figure 2: Schematics drawing of the optical sub-system when used for triangulation Figure 3: Layout of the image sensor The very high dynamic range is achieved by the ProgLog pixel implemented on the image sensor. For low optical input Stereo vision omni-view camera system Placing one camera up-side-down onto another one increases the vertical field of view to -35 to + 35. The overlapping area (-10 to +10 ) allows a stereo view of the captured objects. To calculate the distance D to the objects, the object ray angles of both cameras (α1 and α2) are combined with the distance Dcam between the optical axes of the two cameras: D cam D = tan (α 1) + tan(α 2 ) Conclusion The presented camera module can be used in many different areas, but ideally in applications needing instantaneous omnidirectional view including distance information. Possible application fields are: Automotive, Surveillance and Security, Robotics, Navigation and Collision Avoidance. The Mufly project has been supported by the 6 th Framework Program of the European Commission contract number FP6- IST-034120, Action line: Cognitive Systems. 34

Optoelectronic Test Equipment for Image Sensors and Systems Qualification A. Baumgartner The testing of a circuit is an essential but quite expensive step in the production flow of semiconductor devices. Frequently CSEM customers are looking for small volume production with a high quality level. Therefore a testing environment has been set up to support production verification and qualification in-house with moderate investments and in a very short time after prototype evaluation. This is achieved thanks to the development of very similar routines for both evaluation measurements at the prototype level and for production verification. Following the evaluation of the first prototypes, the set-up of a fully automatic test system for production testing typically requires a large effort and high investments. Quite often for products resulting from leading edge research projects, the standard industry levels of quality are expected but for significantly lower quantities. Furthermore the development of test plans for automatic test equipments (ATE) can be quite costly due to the high time pressure for rapid development cycles and a quick ramp up of the production. Prototype evaluation is a key phase in the development of novel image sensors. This evaluation can be very timeconsuming and needs to be repeated for each new sensor circuit. The measurements done during evaluation are similar to the testing cycles for the production verification. For largevolume production, testing is normally done on dedicated test systems. In this project, a cost-effective evaluation system for production testing was investigated and implemented for low volume production. To be able to verify a device in a short time, special testing features and design for test (DfT) generally have to be implemented: Insertion of structural testing for digital design (blocks) such as the exchange of flip-flops with scan flip-flops Insertion of special dedicated test registers to guarantee the control- and observability of analogue blocks This work has to be done during the design phase and the fault coverage of these tests has to be checked before the end of the design phase. Therefore, a test concept for production testing needs to be done and elaborated before the project design phase starts. For manufactured optical semiconductors, the following procedure is used: Manufacture wafers with PCM structures (=dedicated test structures), verify PCM structures in wafer fabrication site Samples are first tested using a (wafer) prober and a needlecard (probecard) to contact the pads. The failing samples are marked. This first measurement is done in a clean atmosphere (open wafers) in the pre-test site, e.g. in a clean room at CSEM in Zurich. To guarantee correct operation over the full temperature range, this first test is done at one temperature within the specified limits (e.g. hot) The good samples are packaged in single-die packages,on multi-die chip-carriers like Multi-Chip- Packages/Multi-Chip-Modules (MCP/MCM) or bonded directly on circuit boards (e.g. on flexprints ) The packaged samples are tested a second time at a different temperature. An automatic test system for evaluation and small-volume production testing using a National Instruments LabVIEW - based system was chosen as a solution for CSEM. For cost reasons the measurement hardware is based on PC components. It consists of a PC with 19 PXI cards (in 2 external racks), a semiautomatic prober in a dark cabinet and an Ulbricht sphere. With the above described hardware the main challenge is the capability to test semiconductors very fast. Therefore, additional external equipment consisting of a logic analyzer and a pattern generator were integrated into the system. The complete testing set-up is controlled from LabVIEW with the TestStand add-on LabVIEW tool. The test equipment looks as displayed in Figure 1. PXI link Logic Analyzer PXI System Ulbricht sphere RS232 GPIB PC1: LabVIEW 8.5 XP DUT Prober RS232 PC2: Proberbech NT4.0 Figure 1: Schematics of the test equipement. Dark Room Clean Room With this setup, small volume production testing can be performed and an automatic system evaluation flow (system qualification) can/will be easily implemented. CSEM has now the possibility to test optical circuits on wafer as well as on packaged samples. Due to the high flexibility of this system, circuits with high frequency requirements and/or with a high pin count can be tested. Moreover new equipment can be easily integrated in the future. This system implementation was possible thanks to the support of the Wilsdorf foundation which CSEM would like to acknowledge. 35

Highly Integrated Optical Linear Encoder C. Gimkiewicz, E. Innerhofer, A. Perkins, C. Lotto, B. Schaffer, S. Schneiter, D. Beyeler, S. Beer, A. Baumgartner, C. Urban, S. Neukom Optical linear encoders on moving rail systems have to fulfill stringent size and electrical power requirements with distance resolution capacities in the 100 nm range. However, cost related issues like packaging tolerances, ruler quality etc. have also to be taken into account. An optical encoder measures the signal modulation by a light beam reflected or transmitted by a ruler. By interpolation a resolution 100 1000 times below the grating period of the ruler is achieved. Ruler inaccuracies like fabrication errors, degradation effects and dust are partially compensated by imaging (or shadowing) several tens of grid lines onto the encoder sensor. The system development is challenging when a rigorous size reduction is wanted. In the current system under development, the image sensor, the light source, the electronic PCB and the optical module are designed to fit in a total system volume of 50 mm 3. To achieve this compactness the optical paths have to be folded. Figure 1 shows the layout of the optical system. (a) Optical frontend Analog path Analog quadrature signals A/D converter(s) Digital processing Digital quadrature signals (b) Figure 2: (a) Principle of the signal generation A0, A1, A2, A3 in the optical frontend of the image sensor; the yellow squares symbolize the impinging grating pattern, (b) principle blocks of the sensor. Figure 1: Folded telecentric system and illumination system for the miniature linear encoder. A light source illuminates the ruler under a certain angle. The laser written grooves are imaged onto an image sensor with telecentric lens system to achieve high tolerances versus the vertical position of the grating in the order of +/- 0.1 mm. The bright and dark areas detected by the sensor are used to interpolate the travelled distance. Connecting a set of four pixels, sine- and a cosine-wave like signals are generated, yielding the analog quadrature signals shown in Figure 2. Because of the limited lens size, only a few grid lines can be imaged onto the sensor. The ruler can be fabricated in steel, thus stray light has to be taken into account, when designing the stop. This and the specified system speed of up to 5 m/s reduce the overall optical power on the sensor for a measurement cycle. The signal to noise ratio is however dominated by the shot noise (Figure 3). In the designed first amplification stage, the noise level is increased only by 3 db electronic noise to a total SNR of 47dB. The resolution of 0.1 µm or 0.5 µm can be programmed. The signal amplification has to be controlled to optimize the ADC usage and ensure the accuracy in the complete life-cycle. The aging of the light source or the degradation of the laser written grooves due to mechanical abrasion, for example, decrease the signal amplitude. Therefore, in the digital signal processing part of the sensor, a calibration routine has been implemented, which configures the amplification. Figure 3: Spectral noise at the output of the first amplifier stage. The shot noise level reduces the maximum SNR to 50 db, the electronic noise level increases the level over the frequency range by only 3 db. Because of cost the total system assembly will result in alignment errors in the range of +/- 2 concerning the pixel to grid line orientation. This rotational error changes the slope of the analogue quadrature signals. For this reason, a programmable look-up table has been implemented to correct such signal slope deviations and to make the system a good candidate for mass production. This work has been partly financed by the CTI under contract number 8452.1 NMPP-NM. CSEM thanks them for their support. 36

Compact Illumination Modules Based on High-Power VCSEL Arrays C. Gimkiewicz, M. Columbus, S. Schneiter Multi-mode VCSEL (vertical-cavity surface-emitting laser) arrays are candidates for compact illumination modules with applications as flash light illumination for the detailed imaging of fast moving objects (> 100 m/s) or for time-of-flight cameras with modulation frequency in the > 10 MHz domain. CSEM has realized an illumination unit with modulation frequencies of up to 80 MHz and an optical peak output power of 1.3 Watt. VCSELs are prominent light sources in the area of in sensing applications and communication, allowing data rates up to 10 GBit/s. Here, they are proposed for illumination applications, offering a circular beam profile, low fabrication cost and long life-time. Especially for the imaging of fast moving objects they are of interest, since rise and fall times as short as a few nanoseconds are feasible. The optical output power per VCSEL diode is in the order of 10 mw; for a 23 VSCEL array it is in the order of 100 mw and for a complete module it can be in the order of one Watt at a wavelength of 850 nm. An illumination unit with modulation frequencies of up to 80 MHz and an optical output peak power of 1.3 Watt has been realized (Figure 1). In a set-up with 10 VCSEL arrays of this kind, an optical DC power of 565 mw has been demonstrated. Since the signal has a sinusoidal shape, the peak power output is 1.33 W at 80 MHz modulation frequency (Figure 3). It has been achieved with fan cooling, only. (a) (b) Figure 1: Photography of (a) a VCSEL array with 23 diodes (Avalon Photonics), (b) the test board. One may note that for thermal and eye-safety reasons and for the shadow free illumination of the field of view it is of advantage to distribute the laser diode arrays. The developed test board on a thermally conductive substrate has a size of 45 mm x 45 mm and can support at maximum 16 arrays with 23 devices per array (Figure 1). A high power transistor driving circuit provides driving currents up to 1 Ampere. However, in this current range the self-heating of the VCSELs decreases the optical power. In cw mode for a single array with 23 devices, this thermal roll-over occurs at around 380 ma at room temperature. In pulsed mode, the self-heating effect is reduced and peak powers above 130 mw per array can be achieved (Figure 2). Figure 3: Ten VCSEL arrays are modulated at 80 MHz modulation frequency. The red line corresponds to the optical power curve, violet line to the driving current, green line to the voltage and blue line to the fast Fourier transform signal generated over the sampled interval. A draw-back of multi-mode VCSELs is their varying far-field intensity, which is not only dependent on the radiation angle but also on the driving current: marginal areas of an illuminated area suffer from a lower, non-linear illumination intensity at low driving currents, since the higher order modes appear only at higher driving currents (Figure 4a). With the help of a diffusing element, the current dependency of the farfield pattern can be reduced (Figure 4b). The power variation at a far-field angle of 10 is only +/- 10 % compared to over +/- 50 % for a laser diode array without diffuser. (a) (b) Figure 4: Angular intensity distribution in the far-field of a multi-mode VCSEL array for different driving currents; (a) with a glass plate in front of the array only; (b) with a diffusing element at 5.5 mm. CSEM would like to thank Michael Moser from Avalon Photonics. This work has been partly financed by the European Commission under contract number IST-34107. CSEM thanks them for their support. Figure 2: Optical DC power output of a VCSEL array with 23 diodes (Avalon Photonics). 37

Generic Framework for Feature Extraction in Vision T. Zamofing, P. Seitz A vision system that classifies objects in complex, natural scenes has been realized. This software project tries to map structures of the cerebral cortex into a hierarchical binary matched filter [1] implemented on a computer. One of the most ambitious goals in digital image processing is the development of universal classification algorithms, capable of understanding natural scenes with robustness and reliability similar to those demonstrated by natural vision systems, especially by the human visual system. In particular, the functionality of such natural vision systems under very adverse conditions is a highly desirable property for practical applications in machine vision. This robustness can encompass translation invariance, rotation invariance, as well as a high tolerance to distortion (e.g. perspective), to partial occlusion, to reflections and shadows, to unsharp images (focus, movement). It should moreover be independent of local contrast and illumination variations, independent of the background and independent of object texture (surface texture, dirt, etc.). All classification algorithms are faced, from the outset, with the problem that the given continuous-tone images contain a vast amount of information that must be substantially reduced in order to label the different image areas ( the objects ) correctly, according to the class to which they belong. This feature-matching process is realized as a binary matched filter following three assumptions (see Figure 1). (1) Local orientation is a central source of relevant image information. This assertion is corroborated by neurobiologists findings on how natural vision systems work, using directionally selective filter banks. The process employs local orientations as the fundamental picture primitives, rather than the more usual edge locations. (2) The procedures are based on retaining and exploiting the local arrangement of features of different complexity in an image. The technique is based on the accumulation of evidence in binary channels, followed by a weighted, non-linear sum of the evidence accumulators. (3) The algorithm proceeds in a hierarchical fashion, starting at low feature complexity, and raising the level of abstraction at each successive processing step. and file handling) can be written using 60 70 lines of a highlevel language (e.g. Pascal, Fortran or C). Because of the homogeneity and the simple, reusable characteristics of the feature-matcher, it should be possible, with reasonable effort, to develop a hardware implementation running at low power in real time. The current implementation uses a black and white firewire camera with a resolution of 640x480 pixels and is implemented on a PC using SSE (single instruction multiple data) for speedup. With this setup a frame rate of 5 to 25 frames per second (depending on the complexity of the templates) could be achieved. The sample below shows an example (Figure 2) with its templates to detect traffic signs that runs at about 20 fps. Figure 2: Application example: Identification of traffic signs Future work could use the ViSe (www.csem-devise.com) sensor. The advantage of the ViSe sensor is that it directly delivers orientation images with a high dynamic range. Furthermore a FPGA implementation will lead to a smart, low power and portable vision system. [1] G. Lang, P. Seitz, Robust classification of arbitrary object classes based on hierarchical spatial feature-matching, MVA, 1997 Figure 1: The feature matching process is based on a successive hierarchical approach This algorithm can be implemented very easily in a computer program. The essence of the algorithm (i.e. without graphics 38

Efficient Screening and Formulation Optimization for Polymer LEDs R. Kern, T. A. Beierlein, T. Offermans, C. J. Winnewisser A modified pipetting-robot together with an automated opto-electrical characterization system allows speeding up material screening and formulation optimization [1] of solvent processed organic LEDs. This high-throughput apparatus (HTA-7) allows the fabrication and characterization of batches of 49 PLED samples in one experimental run. A concentration sweep of individual blend components can quickly reveal the ideal blend ratio for optimum Polymer LED (PLEDs) composition. PLEDs may consist of multi-component mixtures of dedicated materials in order to adjust the desired properties. Most common goals of formulation optimization include: maximizing efficiency, minimizing driving voltage, maximizing device lifetime, and adjusting the emitting color of the PLED. A promising approach is a host/guest-system, which consists of the matrix material (host) and an emitter material (guest) in small concentrations [2, 3]. Further functional materials can be used to improve the performance. In the following of this report, a four component system is described: i) host (matrix) material, ii) guest (emitter) material, iii) hole transporter (TPD [4] ), and iv) electron transporter (PBD [5] ). Figure 1 shows efficiency values of devices with a fixed yellowish/green emitter concentration of 5%. For this material system PBD concentrations above 20% improve the efficiency but only if at the same time the TPD concentration is in the range of 5-10%. The next step is to check whether the chosen emitter concentration of 5% is optimal. Efficiency / cd/a @100 cd/m 2 50 40 30 20 10 PBD / % 10 20 40 0 0 2 4 6 8 10 12 14 16 18 20 TPD concentration / wt % Figure 1: Dependence of PLED efficiency in dependence of holetransporter (TPD) and electron-transporter (PBD) concentration In Figure 2a the efficiency is plotted as a function of the emitter concentration. The TPD and PBD concentrations were fixed to 5% and 30%, respectively. The emitter concentrations have been varied up to 10%. A steep increase in device efficiency is observed below 2% emitter concentration whereas it starts to saturate at about 10% with values of ~40 cd/a. If the TPD, PBD concentrations will be optimized again for such emitter concentrations even higher efficiencies seem to be possible. Figure 2b shows that the emission spectra exhibit a small shift towards longer wavelengths, when the emitter concentration changes from 0.5% to 10%. The high-throughput fabrication tool (HTF-7) uses the robust spin-coating technique in order to allow forming homogenous thin films of the various blends with different viscosities. However, the ultimate goal is the formulation of high performance electroluminescent inks for applications in the novel market domain of Printed Electronics. a) b) Efficiency / cd/a @100 cd/m 2 EL intensity / a.u. 50 40 30 20 10 0 0 2 4 6 8 10 12 Emitter concentration / wt % 1.0 Emitter concentration / % 0.8 0.5 1 0.6 1.5 2 0.4 7.5 10 0.2 0.0 500 550 600 650 700 Wavelength / nm Figure 2: a) Efficiency as a function of emitter concentration (dotted line to guide the eye). b) Influence of emitter concentration on emission spectrum. Printing will require other additives improving printability. Such additives in turn need to be characterized in terms of electrical influence on the device performance, since small changes in composition of one component might drastically affect the performance of the complete device. This is an ideal task for an automated robot system. CSEM thanks our project partners at Ciba Specialty Chemicals for their valued cooperation and support. [1] M. Kiy, et al. Systematic studies of polymer LEDs based on a combinatorial approach, Proc. SPIE vol. 6333, Organic Light Emitting Materials and Devices X, Z. H. Kafafi, F. So; Eds. (2006) [2] G. E. Johnson, et al., "Electro-luminescence from single layer molecularly doped polymer films", Pure & Appl. Chem., Vol. 67, 175-182 (1995). [3] X. H. Yang, et al., Polymer electrophosphorescence devices with high power conversion efficiencies, Appl. Phys. Lett. 84, pp. 2476-8 (2004). [4] TPD = N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine [5] PBD = 2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole 39

Polymer LEDs Patterned by Ink-Jet Printing M. Ramuz, T. A. Beierlein, C. Winnewisser Electroluminescent polymeric LEDs (PLEDs) have been patterned by an ink-jet printing technology. Ink-jet printing process offers significant advantages for self-emissive pictograms, since it allows adapting with ease the self-emissive area to various layout patterns. A strong market potential is expected for instance in the domain of custom-designed self-emissive man-machine-interfaces and advertising signage applications at retailers. In contrast to inorganic LEDs, organic light-emitting diodes (OLEDs) are surface emitters that moreover provide wide viewing angles. These technological advantages amongst others have allowed OLEDs to enter the market in the form of flat panel displays for applications in PDAs and mp3-players. However, other potential applications are attracting industrial interest as well. Especially in the domain of advertisement, self-emissive custom-designed OLEDs have become an attractive alternative. Low-weight OLED pictograms for example can be produced with thicknesses below 3 mm, allowing completely new applications like incorporating selfemissive logos into showcases and windows. A typical PLED consists of several layers namely the anode, usually indium tin oxide (ITO), one or two polymer layers and the cathode, usually a low work function metal. The total multilayer thickness of such an OLED device is typically less than one micrometer [1]. In principle, every layer can be patterned. Several different patterning steps can be applied in the fabrication process, namely: patterning of the electrodes, patterning of the electroluminescent material, patterning of the charge carrier injection layer, and insertion of a patterned insulating layer. Usually a photo resist layer on the ITO anode layer is patterned by photolithography. However, this process is time consuming and not flexible with respect to the pattern. Consequently such a process is not favorable for customdesigned low volume productions. As ink-jet printer a dedicated commercial ink-jet printer from Microdrop has been used. The lateral resolution of the pictogram is better than 100 µm. This resolution can further be improved by optimizing the print process parameters, like nozzle diameter, ink-formulation, ink droplet formation, surface energies, to resolutions better than 50 µm. Figure 2: Two examples of ink-jet patterned electroluminescent pictograms. Figure 3 shows two different designs of electroluminescent pictograms. The electroluminescent cross has been characterized in terms of its electroluminescent performance, its current voltage characteristic I(V) and its brightness B(V). The device shows an efficacy of 5 cd/a. The power consumption per unit area is 19 mw/cm 2 at a brightness of 100 cd/m 2. Cathode evaporation (70 nm) Spin-coat polymer light-emitting material (70 nm) Spin-coat PEDOT: PSS (50 nm) Pattern logo by printing 100 nm thin PMMA layer as an inverted image ITO (75 nm) Glass substrate Figure 1: Cross section of an electroluminescent pictogram based on organic materials. In order to manufacture arbitrary shapes, an inverted insulating thin film is ink-jet printed onto the ITO layer, as shown in Figures 1 and 2. Charge carriers can be injected only in the insulator-free areas where light emission will then take place [2]. Polymethyl methacrylate (PMMA) can for example be used as printable insulator material. Figure 3: Electrical and optical characterization of a pictogram This ink-jet printing process will allow low-volume fabrication of custom tailored signage applications. [1] Excluding encapsulation layers [2] M. Kiy, et al., Polytronic 2003 IEEE conference proceedings, p.111, 21-23 Oct. 2003 ; WO2004068584 40

Optical Fill Factor Enhancement for Smart Pixels M. Schnieper, C. Zschokke, F. Kaess and A. Stuck The fill factor of CMOS vision chips is significantly enhanced using a one-step replication process of micro-lenses with a custom made replication tool and UV curable ORMOCER material. The use of CMOS technology in imaging devices and vision chips is today well established. The capability of on-chip signal processing directly at the pixel site enables the realization of smart and high-speed vision chips that are very attractive to many application fields. Such vision chips however typically show a low fill factor (defined as the ratio of the optical active area to the full pixel area). It is common to have only 1/10 of the pixel surface area which captures light, resulting in a strong reduction of the sensor sensitivity and a corresponding increase in the required exposure time. One solution to overcome these losses is to integrate a small lens on top of each pixel. This lens needs to be designed carefully in order to match the specific characteristics of the imaging optic used to collect the light onto the vision chip. A technology has been developed to deposit in one single step all the lenses on the chip with a sol-gel replication process. This requires a chrome master and a special replication mould master that incorporates the negative shape of the lenses to be replicated. correction of the micro-lens position with respect to the pixel center (Figure 2) is included in the fabrication of the mould master. This re-centers the focal point on the optical active area of the pixels. Since each vision chip can have a different layout, it is very important to ensure correct alignment. This is achieved by the chrome master. The latter includes alignment marks and also acts as a frame to UV cure the ORMOCER material only where it is needed. In this way the bonding path and other required areas are kept free of ORMOCER. Mask 1 st Replication Figure 3: Representation of the mould master fabrication, with the replication of the reflow lenses onto the Chrome master. The fabrication of the replication tool requires a copy of the reflow lenses onto the chrome master (Figure 3). To ensure a wafer scale process, all the positions of the lens array moulds have to be adjusted to the vision chip silicon wafer layout. Figure 1: Ray tracing for 3 lenses placed respectively in the center of the chip, between the edge and the center and at the edge of the chip. After fabrication of the replication tool, a release layer is applied to it. The release layers developed by CSEM permit between 50-100 replications with the same release layer, before a new release layer has to be applied to the tool. Finally, the replication on the silicon chip can be performed. With one single step a full 5 inch wafer of vision chips can be processed (an example of replicated microlenses is given in Figure 4). Figure 2: Representation of position correction between microlens and pixel position. The most important step in the full process is the fabrication of the mould master. This requires a suitable micro-lens array made by SUSS-MicroOptik reflow lenses. The shape and position are optimized to the specific imaging. The choice of the latter will also define the maximum possible improvement of the fill factor. To avoid vignetting as shown in Figure 1 a Figure 4: Optical and SEM pictures of the manufactured microlenses By using a very wide angle collecting optic, the fill factor has been improved by more than a factor 3. 41

42

MICRO AND NANOTECHNOLOGY Harry Heinzelmann Micro- and Nano- technologies (MNT) are key for applications in many diverse markets. Despite the hype, particularly about the virtues of small technology, innovation only happens if new technologies bring real advantages over current solutions. One way to realize the necessary improvements is by combining R&D efforts in MNT with those in other disciplines such as mechanics, optics, biology, and classical materials science. This allows the full potential of small technology to be unlocked, resulting in new products with new and improved properties. Micro Electrical Mechanical Systems (MEMS) can be produced in different materials and countless shapes. The specific development of MEMS for biological applications (biomems) and of MEMS with optical properties (optical MEMS or MOEMS) is of particular interest. The diffractive grating technology recently developed by CSEM has led to high performance components that can be integrated in portable instruments, such as tunable lasers and spectrometers. Micromechanical cantilever structures find applications in force microscopy, a technique that is of increasing relevance in pharmaceutical and medical research. On the sub-micrometer (or nanometric) scale, plasmonic effects allow the development of components for improved light detection and emission. This is extremely interesting in markets where comparatively small enhancements in performance represent economically relevant breakthroughs. Arrangements of microspheres and molecules in regular nanoscale patterns often give rise to optical effects, which in some cases can be exploited for optical filtering and switching. Alternatively, when combined with MEMS technologies, these arrangements can be transposed into silicon based materials to produce nanoscale membranes. Under different conditions, nanoscale objects often arrange into arbitrary arrangements, with, however, clearly determined statistical characteristics. These patterns can be exploited for anti-counterfeiting purposes. Nanostructured surfaces often show exceptional wetting properties, giving rise to yet different applications of these nano-materials. While sol-gel processes allow the surface properties to be tuned over wide ranges, the electrospinning of polymers allows the preparation of nanofibrous materials that could prove relevant for tissue and organ regeneration. A recent new orientation of biosensing has become possible following the creation of a start-up company to valorize the established WIOS technology. The new activities address the integration of (nano-) sensors in wearable formats such as textiles. The goal is the realization of monitoring systems for medical and physiological parameters, e.g. for ambulant medical applications or integrated in protective wear for high risk professionals. 43

Dissolved Oxygen Sensor with Self-Cleaning and Self-Calibration P. Niedermann, J. Gobet, R. Pfändler, P. Bitsche, S. Liebert-Winter *, P. Jacob *, T. Overstolz, F. Cardot, A. Hoogerwerf, A. Dommann A novel dissolved oxygen sensor for environmental applications has been developed. A gold microelectrode array is used for oxygen measurement and a diamond auxiliary electrode for self-calibration and self-cleaning, resulting in a low-maintenance, long-lifetime (> 1 year) device. Reliability and lifetime issues such as dielectric failure modes were addressed using FMEA methodology in order to systematically solve processing issues and performance limitations. mold patterning, seed metal deposition and gold electroforming. Figure 1: Sewage treatment This innovative sensor is used for membrane-less monitoring of dissolved oxygen in the activated sludge of the secondary treatment stage in sewage treatment plants [1, 2], such as the one depicted in Figure 1. Figure 4: Improvement of diamond patterning The patterning process of the polycrystalline 1 µm thick diamond layer was improved as illustrated in Figure 4, allowing seamless integration of this advanced material into the microsystem. The diamond electrode is contacted by wire bonding, and the diced chips are packaged in sensor heads together with a counter and a reference electrode. Figure 2: Measurement principle The working electrode of the sensor is a gold microelectrode array, measuring an electrochemical current corresponding to the reduction of the O2 molecules. The measurement setup is illustrated in Figure 2. The microelectrodes are insensitive to fluid flow and permit operation in low-conductivity liquids. Figure 5: Weak spot localization The evolution from prototypes with promising performance to a device operating reliably for more than one year was achieved by failure analysis of field tested sensors and corresponding corrective actions in the fabrication process and the measurement protocol, employing failure mode and effect analysis (FMEA) methodology. Dielectric weak spots were localized by optical beam induced resistance change (OBIRCH, see Figure 5) and microdisks were characterized by focused ion beam imaging. This sensor is now being introduced to the market. Figure 3: Individual sensing disk surrounded by auxiliary electrode The sensor chips consist of electroformed gold microdisks (Figure 3), electrically connected to the highly doped silicon substrate, and a patterned diamond electrode with a platinum thin film contact. The diamond acts as a chemically inert auxiliary electrode, providing self-cleaning by generation of potent biocide species at anodic potentials (H2O2, O3, Cl2, OH - ) acting against scale deposition and biofouling, as well as self-calibration by local dissolved oxygen generation by anodic polarization. The fabrication process consists of dielectric layer and diamond thin film deposition, diamond patterning, diamond contact metal deposition and patterning, followed by microdisk The wafers were mainly processed at Comlab, the joint IMT- CSEM cleanroom facility. This work was partly funded by CTI (project n 8039.2). CSEM thanks them for their support. Adamant Technologies SA, La Chaux-de-Fonds Züllig AG, Rheineck * EMPA, Dübendorf [1] J. Gobet, P. Rychen, F. Cardot, E. Santoli, Microelectrode Array Sensor for Water Quality Monitoring, Water Sci. Technol. 47 (2003) 127 [2] EP 04 405039.1 Système d électrode pour capteur électrochimique ; EP 05 103304.1 Procédé d utilisation d un capteur électrochimique et électrodes formant ce capteur. 44

Microfabricated Membranes for Cell Layer Culture and Analysis T. Overstolz, A. Hoogerwerf, M. Liley, F. Spano A microfabricated membrane chip is being developed for cell culture and analysis. Integrated Pt-electrodes allow the detection of intercellular junctions and the evaluation of the tightness of epithelia cell layers. These tools are designed to screen the toxicity of nanoparticles, in particular their capacity to cross biological barriers such as the lungs. Nanomaterials based on nanoparticles have become very popular for many applications, including extremely strong composite materials based on carbon nanotubes. In parallel with this development, there has been a growing interest to study the toxicity of these nanoparticles to the human body. In vitro methods for these tests are being developed in order to complement and/or replace large scale animal screening tests. In the body, epithelial cells are organized in sheets of cells that make up the epithelia. All epithelia have the function of providing a barrier between the body and the external world. In order to achieve this, individual epithelial cells are joined via intercellular junctions that make the epithelium impermeable. Thus, transport across the epithelia occurs essentially through the epithelial cells (trans-cellular transport) rather than between the cells (para-cellular transport). In vitro models of epithelia must be tested for the presence of intercellular junctions and the absence of gaps between cells, to ensure that transport across the in vitro model closely resembles that of the epithelium in vivo. One of the most widely used approaches to determine the tightness of a layer of cells is to measure its electrical impedance. Electrical impedances of around 200 Ohm/cm 2 may be considered representative of good model epithelia that may be used to study transport processes. In order to minimize the influence of artifacts that interfere with impedance measurements in aqueous media (e.g. electrolysis, electrochemical potentials, fouling of the electrode surface), the impedance of cell layers is usually measured using low frequency alternating currents in a 4-terminal sensing approach. In the 4-terminal sensing method, one pair of electrodes is used to inject the current into the system, while a second pair of electrodes measures the potential across the cell layer. Figure 2: Close-up view of Figure 1 showing the square well with the microporous Si3N4 membrane, inset shows a detailed view of the hexagonal hole pattern. To enhance the reproducibility of the measurements the electrode distance and placement should be well defined. CSEM has therefore opted to use photolithography to define the electrodes, rather than the less precise shadow masking Moreover, the precise electrode definition accommodates 2-terminal impedance measurements, which are still in use. A microchip has been fabricated integrating a square well for cell culture including a thin microporous silicon nitride membrane, on-chip platinum electrodes, and inlets for a microfluidic system to supply cell culture medium. A photograph of the resulting chip is shown in Figure 1, whereas a more detailed photomicrograph of the membrane is depicted in Figure 2. Thin silicon nitride membranes are especially suitable for this purpose since they are transparent and thus compatible with the many optical analysis and detection techniques used in cell biology. The fabrication technology starts with the deposition and structuring of the LPCVD nitride layer that will form the membrane. The front side structuring defines the hole pattern in the membrane and the backside defines the opening for the subsequent etch of the substrate material. Prior to this etch, when the wafers do not have much topography, platinum electrodes are deposited and patterned using a photoresist liftoff. Only after the electrodes are defined the substrate is etched in KOH to form the membrane. The next steps foresee the integration of the polymer-based microfluidic system and the electrical measurements of the cell layer tightness. Figure 1: Silicon chip with integrated platinum electrodes for impedance measurement of intercellular junctions. The central cell culture well with its yellow porous Si3N4 membrane is visible. The two other square holes act as fluidics ports. The project partners are the University of Glasgow and the Katholieke Universiteit Leuven. This work was partly funded by the European Commission (Contract number 515843-2). CSEM thanks them for their support. 45

Metal Micro-Parts Fabrication F. Cardot Micro-parts realized by metal electrodeposition onto a silicon mold are presented; the versatility of this process is shown. Combining silicon deep reactive etching (DRIE) and microelectrochemistry leads to the realization of high resolution (~1 µm) and high aspect ratio (up to 30:1) electrodeposited micro-parts. This process is schematically depicted in Figure 1. A silicon dioxide etching mask, (a) is realized at the surface of a highly conductive silicon wafer comprising of a backside electrical contact (b). The silicon is etched by using a DRIE process (c) and the silicon mold thus created is filled by using an electrodeposited metal or alloy (d). The wafer is polished (e) and the electrodeposited micro-parts are released (f) by etching the silicon wafer in a KOH solution. Non-flexible structures like gears (Figure 4), rack and pinion or turbines (Figure 5) have been produced, which could be used in the watch industry. SiO2 Ni a Si d Figure 4: Nickel micro-gears b e Ti c f Figure 1: Schematic of the fabrication process flow of metal microparts This process can be used to fabricate a large range of microparts. For example flexible structures such as springs (Figure 2) or micro- FlexTec structures (Figure 3) have been realized which could find applications in the field of chip testing or for the realization of miniaturized mechanical systems. Figure 5: Nickel turbine and rack and pinion This process can also be used for the realization of 3D folded micro-parts as illustrated in Figure 6. Figure 7 presents an example of a heterogeneous micro-part made of silicon and metal. An 8 µm diameter NiFe ball has been electrodeposited at the top of a silicon needle, 80 µm long and 2 µm across. a b Figure 2: Spring micro-parts. a) FeNi electrical contact pin; b) Ni membrane spring. Figure 6: Nickel folded micro-box Si NiFe 2 m 80 m Figure 7: Electrodeposited FeNi ball on top of a silicon needle Figure 3: Nickel micro-flextec hinges The work has been carried out within the frame of internal research for developing new technologies for MEMS fabrication. 46

Scintillating Fiber Probes for Neurophysiology R. Eckert, B. Weber, A. Buck, M. Liley, R. Ischer, R. P. Stanley CSEM has been working with the University Hospital Zurich to develop optical probes for neurophysiology. The results of this development is a range of probes going from thin probes to be inserted into tissue to large area probes to be used externally for long term measurements. Radioimaging is widely used as a diagnostic tool in medicine as it allows the direct imaging of internal structures such as organs as well as their activity. Of these tools, positron emission tomography (PET) can give highly accurate images of the human body. PET has become extremely useful because compounds used in metabolism can be radiolabelled so that the signal strength is related to internal metabolic activity. Tracing the evolution of these same compounds in time can also give an insight into the dynamics of metabolism. PET is too slow for this, a better option is to use a small probe that can take local measurements in real time. Together with the University Hospital Zurich and Swisstrace, CSEM has developed a range of fiber optic based probes for making local physiological measurements. All fiber probes have two parts, a short part made from special fluorescent fibers and a standard glass or plastic optical fiber to transport the signal to the detection systems. The short fluorescent fibers convert particles (electrons or positrons) coming from radioactive decay that penetrate the fiber, into light. The intensity of the light depends on the energy of the beta particles. Only a very small quantity of light is produced some tens of photons per beta particle. is impossible to tell the difference between fluorescence signal from the fiber coming from s or s. Given that the absorption length for particles is much shorter than that of rays, the ratio between s and s can be improved by thinning the fluorescent fiber to a thin disc 3 mm in diameter but less than 0.2 mm thick. These have been successfully used to monitor the differences in activity between the left and right hemispheres of the brain in real time. A hardware platform was built to read the low light signal from the scintillating fibers (see Figure 1). This includes ultra-low noise detectors that are shielded from stray radiation by integrated shielding. The system is interfaced to a computer via a USB port. Finally, the technology developed for the large fiber probes can also be used to track any radiolabelled material including nanoparticles. The feasibility of using these kinds of measurements to check transport of nanoparticles through biological tissue has been investigated. Initial calculations show that the systems developed can have already sensitivities in the 10-13 Molar range which is much better than competing technologies. This light has to be guided without loss to a very low noise photodetection system. The fibre probes that have been developed have three different diameters, 250 µm, 500 µm and 3 mm. The thinnest fibers can be inserted into tissue without causing damage, while the 3 mm probe has been designed as a surface probe for chronic (long term) measurements. The signal from the thinnest fiber is in the range of 30 counts per second (CPS) under standard operating conditions. However, ambient light can also enter the fiber, producing an unwanted background about ten orders of magnitude larger than the actual signal. In order to avoid working in complete darkness, the fibers have to be perfectly sealed against stray light. Making the fibers light tight is very challenging because the coating has to be completely opaque to light even a single micron-sized pinhole is unacceptable while being thin enough to allow the beta particles to reach the scintillating fiber. In order to achieve total light tightness, an opaque coating is applied in a layered fashion and is carefully tested after each layer to ensure specifications are achieved. Figure 1: The detection system developed by CSEM including ultralow noise uncooled photodetectors. The detectors are protected from background radiation by integrated lead shielding. The system connects to a computer via a USB port. This work was funded partly by University Hospital Zurich and the EU-Project Nanosafe. University Hospital Zurich, PET Centrum, Rigistrasse 56, 8006 Zürich, Switzerland. The large 3 mm probes pose additional challenges. Due to their large area their cross section for rays which come from the disintegration of positrons ( + particles) is rather large. As the rays can travel long distances, they are not a local signal and are therefore an unwanted noise. Optically it 47

Towards an Optical Switch with J-aggregates Monolayers R. Eckert, J. Dintinger, T. Ebbesen, R. P. Stanley J-aggregates are an efficient non-linear optical material. They have been successfully used in ultrafast all optical switches, which exploit plasmonic effects of nano-structured metal surfaces. This work aims to replace 100 nm thick J-aggregate layers in such switches by a monolayer of J-aggregates using a unique deposition technique. Extraordinary optical transmission (EOT) through an array of subwavelength holes drilled in a metal film relies on the interplay of surface plasmons (SP) with the periodicity of the nanostructure to make the otherwise opaque film transparent. EOT is not only a very active field of basic research but is currently finding its way into real world applications and devices. In this experiment, the pump power provided by a cw laser was not sufficient to excite all JA in the excitation volume and thereby to induce a sufficiently big change of the index of refraction necessary to shift the transmission peaks of the hole array. The concept of an ultrafast all optical switch, which exploits EOT, has been demonstrated recently [1]. Its basic component is a gold film with an array of holes covered with J-aggregates (Figure 1). J-aggregates (JA) are formed from cyanine molecules and have well-defined absorption bands. The difference between their ground and excited states is sufficient to change the transmission properties of the array. Consequently, one beam of light (the probe beam) can be switched on and off by exciting the JA with a second beam of light (pump beam). Figure 1: Concept of an all optical switch based on EOT In the original work the JA were randomly dispersed in a 200 nm thick polymer film coated on one side of the hole array. The present work aims at achieving the same effect by using only a monolayer of highly ordered JA formed by a process developed at CSEM using a template of selfassembled dendrimers. Both, the remarkable absorption efficiency of these monolayers and the possibility of coating both sides of the hole array instead of only one offer the potential to achieve bigger switching amplitudes between on and off states of the device. A typical hexagonal hole array with a JA monolayer on one side and its transmission spectrum are shown Figure 2. The holes are milled by focused ion beam (FIB) into a 200 nm thick gold film deposited on a glass substrate. The array period is 525 nm and the hole diameter is 175 nm. The transmission spectrum exhibits two main peaks, which correspond to the surface plasmon resonances at the gold/ja/air interface (left) and the glass/gold interface (right). The dip in the transmission peak at 550 nm is due to the absorption of the JA monolayer which is less than 10 nm thick. Figure 2: a) Electron micrograph of a hole array b) Transmission spectrum of the hole array In the next step of experiments, the JA will be pumped by a pulsed laser, powerful enough to saturate the JA absorption, which ultimately should cause a shift of the transmission spectrum to the blue and thus a real switching of the device. This work was partly funded by the Network of excellence Plasmon-Nano-Devices within the European Framework 6. CSEM thanks them for their support. ISIS, Université Louis Pasteur, Strasbourg, France [1] J. Dintinger, I. Robel, P. V. Kamat, C. Genet, T. W. Ebbesen, Terahertz all-optical molecule-plasmon modulation, Adv. Mat. 18 (2006) 1645 48

Colour Filters Using Polystyrene Microspheres M. Guillaumée, M. Liley, R. Pugin, R. P. Stanley Strong scattering properties are obtained from a single layer of randomly packed polystyrene microspheres, giving rise to structural colours in transmission. The film colour is dependent on the sphere size, but also on the observation angle. These films might be useful for colour filters with low reflectivity. Structural colour is the name given to colours that are dominated by the structure of the material rather than the intrinsic properties of the material itself. Such colours are interesting because they never fade or bleach. An excellent example is the metallic sheen seen from the wings of certain butterflies and beetles. The most well-known structural colours are related to periodic structures (diffraction gratings and interference films). Random media are also known to be the origin of several colour effects. This is the case of colloidal gold and silver nanoparticles, which were already used by Romans to colour glasses. The blue colour of the sky is due to the random nature of Rayliegh scattering. behave as extremely efficient scatterers. Indeed, transmission can be reduced down to 5% at certain wavelengths (see Figure 2), producing strong structural colours. The low transmission range can be shifted by changing the sphere diameter, thus modifying the observed colour. The colour of the film colour also depends on the observation angle (see Figure 3). Figure 3: Dependency of the observed colour in transmission on the tilt angle with 725 nm diameter spheres Figure 1: Scanning electron micrograph showing the random packing of polystyrene spheres In the present work, strong structural colours are obtained with a two dimensional random system [1]. The structures are made with polystyrene microspheres randomly adsorbed onto a glass substrate (see Figure 1). All these optical effects have been reproduced theoretically. In the non-tilted case (see Figure 3a), multiple scattering between spheres is negligible since in this sphere size range light is mainly scattered in the forward direction. The colour effect is due to interference between the light incident on the film and the light scattered by the spheres in the forward direction. When the spheres are no longer lying in a plane perpendicular to the incident light (see Figure 3b), forward scattering from one sphere even at a small angle can irradiate neighbouring spheres, modifying the transmitted spectra. This work was partly funded by the COST project P11, MieOpic. CSEM thanks them for their support. [1] M. Guillaumée, M. Liley, R. Pugin, R. P. Stanley, Scattering of light by a sub-monolayer of randomly packed dielectric microspheres giving colour effects in transmission, Optics Express 16, (2008), 1440 Figure 2: Transmission spectra in the visible for dense layers of sphere diameter Ø Experimentally various degrees of coverage have been investigated and the sphere diameter has been varied from 0.2 to 1 µm. When optimized, the spheres in such films 49

Towards Plasmon Enhanced Detectors L. A. Dunbar, M. Guillaumée, R. Eckert, E. Franzi, R. P. Stanley Surface plasmons play a key role in the recent experiments on extra-ordinary optical transmission through nano-structured metals. By tailoring these nanostructures they can be used to enhance optical transmission, with polarisation and spectral selection. Incorporating these nanostructures directly onto photon detectors can improve their performance. To enhance the signal to noise ratio of detectors one can either enhance the signal or reduce the noise. Recently Ebbesen et al [1] measured extraordinary optical transmission through sub-wavelength holes in an otherwise opaque metal. By exploiting this effect, light can be harvested on photodetectors and the signal to noise ratio can be increased. Currently CSEM is fabricating metallic nanostructures on image sensors to do just this. Additionally these nanostructured metallic films can act as spectral and polarization filters or a combination of the two. Initial trials have been made to investigate the enhanced transmission through a single slit surrounded by a series of grooves. Incident light is converted into a surface wave (plasmon) by the periodic array of grooves. The light is transported along the surface towards the central slit. This allows light which does not fall on the central slit, to pass through the slit and increase the signal that can be detected with the detector under the slit. As the shot noise depends on the size detector, increasing the signal whilst maintaining the same detector size increases the signal to noise ratio. Initial results give a factor of 5 enhancement per surface area over a spectral bandwidth of 25 nm. Figure 2 shows the transmission through a structured film for different film thicknesses and shows that the spectral features can be tuned by varying the metal thickness. Figure 2: Transmission spectra calculated using 2D-Finite Difference Time Domain (FDTD) for different metal thicknesses. The peak transmission shifts to longer wavelengths with increased metal thickness. To obtain the desired optical properties is not straight forward as there is a complex interplay between the various parameters. Moreover the metal smoothness is crucial both for losses and to obtain the necessary fabrication tolerances. The fabrication of tailored nanostructures is currently being undertaken by focused ion beam which gives both the flexibility and the precision required. This work was partly funded by the PLEAS as part of a EU Project in framework 6. [1] T. W. Ebbesen, H. J. Lezec, H. Ghaemi, T. Thio, P. A. Wolf, "Extraordinary optical transmission through sub-wavelength hole arrays," Nature 391, (1998), 667-669 Figure 1: Scanning electron micrograph showing a slit delimited by 5 groove structures A typical structure is shown in Figure 1. Here 140 nm of gold has been deposited onto a CSEM made Vision Sensor. The metal has a very low surface roughness. The structures can be optimised for improved signal to noise ratio, for a specific spectral width or for polarisation sensitivity. In order to do this the metal thickness, the width and depth of the groove, the period of the grooves and the initial distance from the centre of the slit to the first groove need to be optimised. Slit structures are intrinsically polarisation selective and by varying these parameters spectral selectivity can also be modified. 50

Unique Marking for Traceability and Anti-Counterfeiting Applications N. Blondiaux, D. Hasler, E. Franzi, R. Pugin A technique for the fabrication and identification of unique labels is presented. It is based on the creation of random structures on the surface of the label and the shape analysis of the structures which acts as a unique fingerprint. The fingerprints produced are then recorded in a database which is used when a labeled product has to be authenticated. Counterfeiting of goods is a topical issue for the global market. For the Swiss industries alone, the losses due to counterfeiting are estimated at 2 billion CHF per year [1]. Many markets (tobacco, pharmaceutics, food, luxury goods) are affected by this rising problem. To fight counterfeiting, companies must constantly develop more advanced and tamperproof technologies to make their products difficult to counterfeit. Another approach is to add identification labels on the products to ensure their authenticity and traceability throughout their lifetime. Figure 2: Optical image of a random structure obtained by means of polymer demixing The identification system enables checking the authenticity of the object by using computer assisted microscopy techniques. The microscope takes several images of the label and selects the sharpest ones. The image analysis method permits then the identification of complex shapes in the image and their distribution for comparison with references stored in the database. Figure 1: Workflow for the identification of a labeled item By combining CSEM competences in nanotechnologies, microfabrication and imaging / vision sensor technology the complete chain for the identification of unique objects [2] could be developed. The fabrication of labels is based exclusively on self-assembly processes, which are difficult to reproduce and are extremely low cost. The technology is based on the fabrication of random micro- / nano-structured labels as unique fingerprints. After fabrication, the random structure of the label is characterized e.g. by means of microscopy and recorded in a database. When a labeled product is being checked for authenticity, the random structures of the label are analyzed (shape analysis, size distribution) and compared with those of the database (see workflow in Figure 1). The structured labels are fabricated by means of polymer demixing. In this process, two immiscible polymers are first dissolved in a common solvent and the solution is spin coated on a substrate. During spin coating, the system phase separates, which leads to the formation of a structured polymer film at the end of the process. As can be seen in Figure 2, the final structures have a well defined average size but are random in terms of shape and distribution. The average lateral size of the structures can be tuned from hundreds of nanometers to tens of micrometers by changing parameters such as the concentration of the solution, the spin speed or the molecular weight of the polymers In Figure 3 such an identification system is presented, specifically designed to analyze labeled credit cards. Once the image of the label is acquired on a computer, the structures are analyzed using custom-made software and compared with those in the database. The system can then authenticate if the credit card has been registered in the database. Figure 3: Schematic of the optical characterization system specifically designed for the identification of credit cards The flexibility of the described approach in terms of fabrication and characterization allows the customization of the complete chain to the type of object to label. Currently CSEM target markets include mainly luxury brands. [1] Institut Fédéral de la Propriété Intellectuelle, Contrefaçon et piraterie, Etat des lieux en Suisse, (2004) [2] Patent pending 51

Sol-Gel based Nanoporous Layers as New Sensing Interfaces E. Scolan, V. Monnier, R. Steiger, R. Pugin Sol-gel processes are very versatile and well-suited for the deposition of layers with controlled homogeneity, thickness, porosity and associated surface structures. The high surface area generated by the porosity and the pore size and shape are used to improve the sensitivity and the selectivity of specifically designed sensors, respectively. Nanotechnology creates functional materials, devices, and systems by controlling matter at the atomic and molecular scales, thus resulting in novel exploitable properties and phenomena. The control at the nanometer scale is especially important in the sensor world since most chemical and biological sensors, as well as many physical sensors, depend on interactions occurring at these scales. Sol-gel processes [1] can be broadly defined as the preparation of designed metal oxide materials at the nanometer scale (including fibers, powders/particles, shaped/molded bulks, (thin) films). The gentle wet chemistry route to ceramics has many advantages. One of the most technologically important aspects of sol-gel processing is that, prior to gelation, sols are ideal for preparing thin films, using common coating processes such as dipping, spinning, spraying or spreading using a blade, a roll or a bar (see Figure 1). The thickness (from 10 nm to 100 µm) and adhesion to different kinds of substrates (glasses, plastics, ceramics, metals, and textiles) can be controlled over a large range of areas (cm 2 to m 2 ) with a high degree of homogeneity. These processes are a bottom-up approach from molecular precursors to high purity particulate nano-building blocks (NBB): their stacking within the film generates tunable porosity by modifying NBB size, shape, surface chemistry and interaction with porogenic species. Highly homogeneous nanoporous layers of silica or aluminum oxide have been prepared (see Figure 2). Finally sol-gel processes are an ambient temperature deposition technology, allowing interfaces with organic and biological species. Thus film porosity can be functionalized by grafted or embedded sensitive entities (e.g. dyes, proteins, polymers or cells), that makes the loaded layers suitable for high performance chemical sensing applications (see Figure 3). Nanoporous sol-gel matrices possess chemical inertness, physical rigidity, negligible swelling in contact with liquids, high thermal stability and optical transparency. Moreover the large surface area generated by the nanoporosity greatly improves the sensitivity of the sensing films to detect specific diffusing gases or diluted (bio-)molecules. For instance, optical CO2 gas sensors have been developed based on the absorbance quenching due to the interaction of CO2 with encapsulated chromophores [2]. Figure 1: Bar coater device and plastic sheet bar coated with a nanoporous sol-gel layer Figure 3: Concept of nanoporous film based sensor Due to their tunable size and shape, nanoporous sol-gel coatings can be integrated into various kinds of devices. Nanosensors and nano-enabled sensors have applications in many industries, among them environmental protection, transportation, communications, building and facilities, medicine, safety, textiles and packaging. CSEM thanks the OFES and EC (www.napolyde.org) for their financial support. Figure 2: Specifically designed SiO2 (top) and AlOOH (bottom) based nanoporous sol-gel layers [ 1 ] J. Brinker, G. Scherer, Sol-Gel Science, The Physics and Chemistry of Sol-Gel Processing, Academic Press, San Diego, (1990) [2] J.F. Fernández-Sánchez, R. Cannas, S. Spichiger, R. Steiger, U.E. Spichiger-Keller, Optical CO2-sensing layers for clinical application based on ph-sensitive indicators incorporated into nanoscopic metal-oxide supports, Sensors and Actuators, B 128, (2007) 145 153 52

High Aspect Ratio Nanopores in MEMS Compatible Substrates A.-M. Popa, R. Pugin, M. Liley One of the objectives of the European project Biopolysurf is the design and fabrication of smart nanovalves for biology-related applications. The work presented below concerns the production of nanoporous thin films that will be subsequently functionalized with temperature responsive macromolecules for the fabrication of smart freestanding nanoporous membranes. The fabrication of nanoporous membranes is of considerable interest for many applications including ultrafiltration, osmosis, prevention of particle emission, high throughput DNA sequencing and biosensing. The fabrication of 2D nanopore arrays in ultrathin (freestanding) membranes can be accomplished by standard top-down fabrication techniques including Nano Imprint Lithography, Electron Beam and Focus Ion Beam; however, these techniques are currently still limited to structuring very small areas, and therefore, to prototyping. An alternative approach is the well-known bottom-up approach, where to scale up the structures one takes advantage of the tendency of molecular building blocks to self-organize. The bottom-up methods used for the fabrication of ultrathin films generally include Langmuir-Blodgett deposition, layer-by-layer assembly, sol-gel or various biomimetic techniques; however, only few approaches such as colloidal and block-copolymer lithography have allowed the fabrication of 2D nanopore arrays in ultrathin membranes for industrial applications. Recently, CSEM has developed a silicon based freestanding nanoporous membrane in which the pore diameter can be tuned between 10 and 20 nm. The membrane is 60 nm thick and has been fabricated by combining standard microfabrication processes and block-copolymer lithography (a nanostructured block-copolymer thin film is used as etch mask for the transfer of the self-assembled structure into the underlying material by deep reactive ion etching). With this technology, the formation of pores with aspect ratios up to 1:5 could be demonstrated [1]. The nanoporous membranes are fabricated with a support structure which makes their manipulation and integration in macroscopic devices straightforward. Based on these first results and with the main objective to improve pore size distribution and the mechanical robustness of the membrane, a new clean room compatible and wafer scale applicable etching process has been developed for thicker silicon based nanomembranes. Once spin-coated, the block-copolymer thin film is directly used to pattern an intermediate metal hard mask. This additional step allows to be reached a much higher selectivity of the etching process (slower degradation of the mask) resulting in the formation of pores with aspect ratios higher than 1:10 into a silicon nanomembrane. The nanoporous thin membranes fabricated in this way are shown in Figure 1. narrow and the mean coverage of membrane surface by pore openings is ~20% of the total area. Figure 1: Scanning Electron Microscopy (SEM) images (top views and transverse sections) of silicon nanoporous substrates with 80 and 40 nm diameter pores. Another big advantage of this approach is the tunability of the pore size and filling factor (ratio of pores to solid area), which are both directly linked to the polymeric micellar mask in terms of diameter and inter-particle distance, respectively [2]. The next step will be the release of the nanoporous membranes using standard microfabrication techniques. Subsequently, the suspended membranes will be modified with temperature responsive polymers, in order to achieve the foreseen reversible valve function within the pores. Applications such as ultrafiltration or biosensing are currently under investigation. This work was partly funded by the OFES and the European Community via the European Research Training Network project BIOPOLYSURF. CSEM thanks them for their support. [1] A. Hoogerwerf, et al., Reinforced Nanoporous Membranes, CSEM Scientific and Technical Report 2006, page 41 [2] S. Krishnamoorthy, R. Pugin, H. Heinzelman, J. Brugger, C. Hinderling, Adv.Funct.Mat., 16, (11), (2006), 1469-1475 According to Scanning Electron Microscopy (SEM) analysis, the pore channels are parallel throughout the membrane (lateral undercutting has been avoided using highly anisotropic DRIE process) and are densely packed in a hexagonal configuration respecting the initial micelles selfassembled structures. The pore size distribution is very 53

Nanoporous Membranes for Medical Diagnostics and Drug Discovery C. Santschi, R. Pugin, V. Spassov, S. Berchtold, A. Hoogerwerf Understanding cellular signaling controlled by cell surface receptors, ion channels and pumps is a key issue of modern biological research and drug development. A platform for high throughput measurements, namely, impedance spectroscopy and fluorescence microscopy, has been developed and is described below. A nanoporous SiO2/SixNy membrane, where native vesicles can be self-assembled, forms the core of the device. These membranes combined with microfluidic channels are the main components of the modularly built-up unit. A rapidly growing number of molecular targets discovered by functional genomics and potential therapeutic compounds produced by chemical synthesis increases the need to downscale probe formats in order to accelerate functional screening, and to reduce reagent consumption [1], and costs. Recent progress in micro- and nanotechnology allows the fabrication of suspended nanoporous SiO2/SixNy membranes appropriate for screening transmembrane receptors and signaling pathways of mammalian cells. In the frame of this project financed by CCMX, a versatile platform allowing highthroughput electrochemical spectroscopy and fluorescence measurements has been developed. The realization of this platform is a challenging task merging micro, and nanotechnology. The modularly built platform consists of three parts: a micro-fluidic component 1), PCB based Si chip-holder containing SiO2/SixNy membrane 2), and cover 3) (Figure 1). 3) PDMS-Sealing 2) 1) Glass cover slide Chip holder PDMS-Sealing Glass cover slide Fluidic channel Glass cover slide Microscope Fluidic in- and outlets Si chip (Figure 3) PDMS Figure 1: Schematic drawing of the modular platform with 1) cover 2) chip-holder 3) micro-fluidic component. A system of micro-fluidic channels is sealed between two glass cover slides. The chip-holder is fabricated using a PCB board commonly used in industrial electronics. An image of the chip-holder PCB is displayed in Figure 2. The PCB contains rectangular apertures, where the individual silicon chips are placed. Moreover, electric contacts are directly integrated on both sides of the double layered board. The cover consists of a glass cover slide and a PDMS sealing layer. Figure 2: a) Image of the PCB chip-holder with mounted Si chips. The size of the board is 4 x 10 cm 2. b) Closed view showing a blank cutout where the individual chips can be mounted. The maximum thickness of the cover is governed by the focal distance of a fluorescence microscope, which can be as short as 350 μm. The micro-fluidic part of the device is sealed between two glass cover slides. SiO2 Pt Figure 3: Schematic cross-section a Si chip containing a membrane The SiO2/SixNy membranes are fabricated from a 4 inch silicon wafer using standard microfabrication techniques. The wafer is divided into chips of 5 x 10 mm 2 each containing a 50 x 50 μm 2 freestanding membrane. A schematic crosssection of the chip is displayed in Figure 3. For size selective positioning of the vesicles of interest, each membrane contains nine cavities etched in the SiO2 layer. Furthermore, each of the cavities contains a single nanopore of 50 nm in diameter in the center of the underlying SiN membrane as illustrated in Figure 3. The diameter of the cavities lies in the range of 1 2 μm. For prototyping, cavities and nanopores have been fabricated using a Focused Ion Beam (FIB) technique. FIB is a versatile tool which allows surface structuring by local material removal. The interaction between a focused Ga + -beam and the substrate results in a physical removal of material due to a momentum transfer from the incident ions to the target atoms. Using FIB, structures of almost any user-defined geometry larger than a few tens of nanometers can be realized; thus, it is an appropriate tool for the fabrication of nanopores [2]. 500 nm Figure 4: Image of the Si-wafer and SEM micrograph of an individual cavity fabricated using FIB technique Figure 4 shows an image of a wafer containing several thin membranes and a SEM micrograph of an individual cavity with nanopore fabricated with FIB. The next step in this project will be to perform impedance spectroscopy and fluorescence microscopy measurements in order to validate the platform performances for drug discovery applications. This project has been financed by the Competence Center for Materials Science and Technology (CCMX) and the CSEM. [1] S. A. Sundberg, Current Opinion in Biotechnology, 11, (2000) 47-53. [2] C. Danelon, C. Santschi, J. Brugger, H. Vogel, Langmuir 22, (2006) 10711-10715. SiN 54

Stimuli-Responsive Surfaces and Smart Coatings F. Montagne, R. Pugin Due to their unique switchable properties, stimuli-responsive polymers have been attracting considerable attention in biotechnologies and successful applications have already been demonstrated in sensing, intelligent textiles and bioseparation. As an illustration of CSEM activities in the field of smart surfaces, presented here are MEMS compatible surfaces modified with poly(n-isopropylacrylamide) (PNIPAM), a thermoresponsive polymer allowing the control of surface wettability. Stimuli-responsive polymers, also referred to as smart polymers, are a very interesting class of polymers since they exhibit marked and rapid conformational changes in response to external stimuli such as temperature, ph, electric field or ionic strength. When grafted to surfaces, they confer to materials unique surface properties as they have the ability to control hydrophilic/hydrophobic balance, roughness, adhesion or permeability. In the frame of HYDROMEL European Project [1], efforts were particularly focused on thermally responsive polymers and developed methods for modification of silicon and gold surfaces with thin poly (N-isopropylacrylamide) (PNIPAM) films. In water, free PNIPAM chains exhibit a very sharp transition temperature, called LCST (Lower Critical Solubility Temperature), at about 32 C. At temperatures lower than 32 C, PNIPAM chains hydrate to form expanded structures, whereas they dehydrate and collapse at temperatures above the LCST. It is a challenge to preserve these remarkable hydration-dehydration changes when polymer chains are covalently attached onto a surface in just a few nanometer thick films. A first grafting method that has been developed consists in the covalent immobilization of end-functionalized PNIPAM under melt using reactive silanes as intermediate coupling agents (ICA) (Figure 1). It is worth mentioning here that the process can easily be adapted for the grafting of any kind of functional polymers onto various types of reactive surfaces (plane or colloidal). pattern molecules on surfaces. Briefly, the stamp is first 'inked' with a solution of molecules, dried and then pressed onto the surface to be patterned. The soft PDMS stamp makes conformal contact with the surface and molecules are transferred directly from the stamp to the surface within a few seconds. As shown in Figure 2, µcp has been successfully adapted for direct grafting of thiol-terminated PNIPAM chains onto gold. Figure 2: SEM picture of thermally responsive PNIPAM microdomains printed onto gold surface. Size of the domains = 128 microns. Thermally responsive surfaces are currently evaluated at CSEM for reversible capture and release of cells. First results show that cells adhere and proliferate on PNIPAM-modified surfaces at 37 C (above LCST) and can then be released by simply decreasing the temperature to 27 C (below LCST). Based on these results, the year 2008 will see the creation of patterned thermo-sensitive surfaces with tuned dimensions for individual cell immobilization, as well as integration of these components in automated system for cell transfection. This work was partly funded by the OFES and the European Community via the European project HYDROMEL. CSEM thanks them for their support. [1] HYDROMEL: Hybrid Ultra Precision Manufacturing Process Based on Positional and Self-Assembly for Complex Micro- Products Sixth framework programme priority (NMP) Figure 1: Grafting process for covalent immobilization of tethered PNIPAM on silicon surface and evidence of surface responsiveness for a 6 nm thick PNIPAM film. In the present case, responsive properties could be evidenced by surface energy measurements showing an increase of the water contact angle when the temperature is raised above the LCST (Figure 1). Force measurements performed using Atomic Force Microscopy in a liquid environment also attested to a change in the profile of repulsive forces below and above the theoretical value of LCST. Thermally responsive micro-patterned surfaces have been created using micro-contact printing (µcp). This technique, also referred to as soft lithography, uses a PDMS stamp to 55

Parallel Nanoscale Dispensing of Liquids for Biological Analysis A. Meister, J. Przybylska, P. Niedermann, C. Santschi, M. Liley, H. Heinzelmann Nanoscale dispensing (NADIS) is a technique developed at CSEM to dispense ultrasmall volumes of liquid using specifically fabricated scanning force microscopy probes. The NADIS probes consist of hollow cantilevers connected to a reservoir located in the chip body. Arrays of NADIS probes have been developed and produced by micromachining in order to dispense biological liquids in parallel. The precise handling of liquids with volumes in the femto- and attoliter range is a challenging task, and one that is becoming increasingly important for specific applications. For example, local surface functionalization with biomolecules is used to create high-density microarrays for diagnostics and biology. In the future, local application of candidate drugs or nanoparticles on biological cells may be used to study their influence on the cell in pharmacology or cytotoxicology. In CSEM s nanoscale dispensing, or NADIS, the ability to dispense ultrasmall volumes of liquid at precise positions on a sample is made possible by combining scanning force microscopy (SFM) with a custom designed microtool. The NADIS microtool is similar to a standard SPM probe, except that the cantilever and the tip are hollow. The microfabrication process for the NADIS cantilevers is shown in Figure 1. In order to increase NADIS throughput, systems with multiple cantilevers were developed. Various designs were defined, with different cantilever geometries and dimensions. Some of them are shown in Figure 3 and 4. Different microfluidic connections between the cantilevers and the reservoirs were also designed. All cantilevers in an array can be connected to one reservoir, so that all dispense the same liquid. Or, if different liquids are to be dispensed, each cantilever can be connected to its own reservoir. Cantilevers with a double beam structure are connected to an inlet and an outlet reservoir, allowing rinsing of the cantilever by flushing a liquid through it. Tests of these new systems are now underway. Figure 1: Fabrication process of the NADIS cantilever probes. a) A wafer is structured with reservoirs and V-grooves for chip release. b) A second wafer is processed for microfluidic channels and pyramidal tips with a silicon nitride layer. c) The pre-structured wafers are brought together and aligned. d) The wafers are fusion bonded and a silicon oxide layer is grown by thermal oxidation. e) The hollow cantilever is released by wet etching. f) The chip is released. Figure 3: Optical micrograph of two chips with NADIS probe arrays of different designs (scale bar: 500 µm). The chips are still attached to the wafer. Figure 2: Example of glycerol droplets (left, optical micrograph) deposited with a tipless NADIS probe (right, SEM micrograph) The hollow core of the cantilever is instrumental for the dispensing process as it connects an aperture in the cantilever tip to a liquid reservoir in the body of the chip. Once the reservoir is filled with liquid, the hollow cantilever and tip will be filled by capillarity. Transfer of liquid from the tip aperture to the surface occurs when the tip is brought into contact with the sample. First proof of principle experiments demonstrating NADIS dispensing with glycerol are shown in Figure 2. Figure 4: Scanning electron microscope (SEM) micrographs of NADIS probes. a) Array of NADIS probes. b) Detail of an array. c) Close-up head-on view of a pyramidal shaped tip. d) Detail of a tip with the aperture at its apex. The partial support of the Swiss Federal Office for Education and Science (OFES) in the framework of the EC-funded Project NaPa (Contract no. NMP4-CT-2003-500120) is gratefully acknowledged. 56

Electrospun Scaffolds for Tissue Engineering F. Spano, M. Liley, C. Hinderling, H. Sigrist A novel nanofibrous material is being developed to be used in three dimensional scaffolds for the directed growth of cells, e. g. in nerve regeneration and guiding. The material will be produced in the form of an aligned mat of nanofibers by electrospinning. The potential of electrospun polymer nanofiber mats in tissue engineering has been established. There is strong medical interest in the development of scaffold materials for tissue regeneration and 2D and 3D cell culture. In the USA, the shortage of donor organs results in the deaths of over 6000 people each year. In 1990, there were more than 9000 patients waiting for organ transplants than there were donors, while today the difference is over 55000 [1]. Tissue engineering could potentially make a major contribution to reducing this shortage of donors. Tissue engineering includes all the techniques that combine cell biology, engineering and biochemistry to replace, repair or regrow injured or diseased organs: a way of producing natural or synthetic organs and tissues by mimicking nature. Electrospinning is a flexible and effective technique for the fabrication of polymer nanofibers. In this process, a solution of polymer(s) is fed at a continuous rate through a capillary. The capillary is charged to a high voltage (20 kv) with respect to a grounded counter electrode (Figure 1). This results in very high electrical fields at the capillary tip leading to the deformation of the polymer solution into a cone (the Taylor cone ) in response to the electrostatic forces. If the electric field exceeds a certain threshold, the electrostatic forces overcome the surface tension: a thin jet of liquid is ejected from the tip of the Taylor cone and travels towards the counter electrode. a) b) 20 µm 50 µm Figure 2: Phase Contrast Light microscopy (a) and Laser Scanning Confocal Microscopy (b) images of Neural Stem Cells attached on aligned PLLA nanofibers [3]. Simple techniques [4] have been used to control and guide the nanofibers during electrospinning and create an anisotropic geometry, e.g. an uniaxially aligned array. Electrospinning onto shaped electrodes (parallel strips) has been particularly successful [5]. The diameter of the dextran fibers obtained is between 100 nm and approximately one micron. The morphology of the fibers can be tuned systematically by varying any one of a number of parameters such as concentration, voltage and distance to the counter electrode. Defect-free electrospun Dextran nanofibers (Figure 3a) have been generated in the form of aligned arrays (Figure 3b) and can thus mimic the structure of the native extracellular matrix (Figure 3) while exerting an orienting influence. a) b) 50 µm Figure 3: a) SEM image of electrospun nanofibers. b) Optical image of aligned electrospun nanofibers. Figure 1: Schematic of the electrospinning process In tissue engineering, electrospun nanofibrous materials have been used as three dimensional scaffolds for the directed growth of cells, e.g. in nerve regeneration and nerve guiding. The key property that differentiates electrospun materials from alternative tissue engineering materials is that they mimic the structure of the extracellular matrix (ECM) (Figure 2). The native ECM provides more than just a mechanical support for cells, it also serves as a substrate to display specific ligands and factors that control cell adhesion, migration and regulate cell proliferation and function [2]. The addition of ligands to electrospun materials potentially offers a simple way to control structural alignment and promote target cell binding. Different polymers can be used for electrospinning. This study focuses in particular on Dextran, a polymer known for its biodegradable and biocompatible properties. The following months work will focus on the introduction of biological guidance cues for the controlled growth of cells on or in aligned electrospun nanofibers. This work is done within the framework of the CCMX Project called FUNFIBER with the collaboration of Arrayon Biotechnology. Arrayon Biotechnology, Neuchatel, Switzerland [1] American Society of Transplant Surgeons - www.asts.org [2] F. Yang, et al., Biomaterials, 26, (2005), 2603 2610 [3] F. Yang, et al., Biomaterials, 26 (2005) 2603 2610 [4] X. Mo, et al., Macromol. Symp. (2004), 217, 413-416 [5] Y. Xia, Adv. Mater., 16, No. 4 (2004), 361-366 57

Detection Methods for Nanotoxicology S. Angeloni, V. Matera, E. Verrecchia, M. Liley An understanding of the risks due to the short and long term toxicity of engineered nanoparticles requires the collection of a new body of data on nanoparticle toxicity. In vitro methods can contribute to the understanding of the mechanisms by which NPs enter the human body, but require a sensitive nanoparticle detection technique. Inductively coupled plasma mass spectroscopy is a promising candidate technique. An assessment of the hazards due to engineered nanoparticles (NPs) is highly complex, requiring extensive data collection on, among other things, the toxicology of NPs. One approach that can contribute to this assessment is based on the use of absorption models dealing with oral, inhalation and topical absorption of NPs (via the intestines, the lungs, and the skin, respectively) [1]. and gold NPs (Au, mean size less than 2 nm [3] ). The NPs were analysed as pure suspensions, as blends of different NPs and also in cell culture medium (Figure 3). No interference was detected between the different NPs or from the culture medium. A linear response was observed for all selected NPs allowing not only detection but also facile quantification. In addition, the sensitivities obtained achieved the desired detection limits. Figure 1: An in vitro model of biological barriers for nanotoxicological tests: a) transport of NPs to the biological barrier; b) microfabricated well for cell culture; c) cell culture chamber divided in two by a thin porous membrane (d) layer of epithelial cells acting as model biological barrier; e) detection of NPs by ICP-MS (see Figure 2). In vitro assays based on model biological barriers can contribute to the understanding of the mechanisms by which NPs gain access to the body (Figure 1). Studies on the transport (translocation) of NPs across these barriers require a detection method for NPs with excellent accuracy and sensitivity. Optical methods such as fluorescence detection or light scattering can be extremely sensitive. However, fluorescence labeling has been found to alter the transport properties of the NPs, while scattering methods have been found to lack specificity. Fi gure 3: ICP-MS response (vertical axis) against known concentration for gold (top graph) and CdTe NPs (lower graph). A linear response is obtained despite size differences or the presence of multiple NPs or cellular culture medium. Figure 2: Diagram of an inductively coupled plasma mass spectrometer (ICP-MS, Perkin Elmer): the liquid sample is introduced (a) into a radiofrequency plasma (b). Ions generated are extracted from the plasma - (c) and (d) - and separated according to their mass-to-charge ratio by a mass spectrometer (e); detector (f). As an alternative to optical detection, inductively coupled plasma mass spectroscopy (ICP-MS) has been tested for the detection and quantification of nanoparticles (Figure 2). ICP- MS is a classical technique based on the chemical identification of the NPs and profiting from recent improvements to achieve a better sensitivity (multi-element ultra trace analysis) [2]. Different water-soluble NPs were analyzed by this technique, namely, a commercially available titanium oxide NP suspension (TiO2), cadmium telluride quantum dots (CdTe), gold colloids (Au, mean size 20 nm), In conclusion, the detection and quantification of NPs has been shown to be possible for inorganic metal NPs down to concentrations of 0.1 ppb (microgram/liter). Next steps will involve greatly reducing the sample volume (currently 1 ml) in order to make ICP-MS based detection compatible with a miniaturized screening test. This work was partially financed by the European Commission in the framework of NANOSAFE2 (NMP2-CT-2005-615843). CSEM thanks them for their support. Institut de Géologie et Hydrogéologie, University of Neuchatel, Switzerland [1] Cell Culture Models of Biological Barriers. Lehr, C.-M. ed.; Taylor and Francis: London, (2002), 430 [2] D. Beauchemin, Anal.Chem., 78, 12, (2006) 4111-4136 [3] C. Gautier, et al., J.Am.Chem.Soc.,128, 34, (2006) 11079-11087 58

Using Microtopography to Study Cell Elasticity M. Giazzon, N. Matthey, G. Weder, M. Tormen, T. Overstolz, M. Liley Tissue engineering and regenerative medicine are of increasing importance as global life expectancy increases. The development of surfaces to control cell adhesion and proliferation can make an important contribution to these fields. In this context, microtopographies are used in studies of the elasticity of human bone cells and as a tool to influence cell growth and survival. Micro and nano-topography can be used to promote or inhibit the proliferation of biological cells. One major field of application of this effect is that of tissue engineering and regenerative medicine. The control of cell proliferation is of increasing importance in medical implants with the potential to accelerate their integration in the body, to reduce the risk of infection or to avoid undesired cell growth in specific areas. For this reason a number of research groups are developing structured surfaces to improve and control the adhesion and proliferation of living cells [1]. grooves: close to the centre of the structure the cell is unable to align to grooves with a high curvature: the actin fibers and the cell span the ridges with no alignment. However, when the depth of the grooves is 500 nm or more, a large number of cells undergo apoptosis, or programmed cell death. CSEM has been developing microtopographic structures in order to study one specific aspect of cell behaviour that contributes to cell proliferation or death: cell elasticity. This is the capability of a cell to bend in response to a physical stimulus. Indeed cells may bend following a stimulus or when they encounter a mechanical hurdle, but there is a limit above which they cannot curve [2].Varying the microtopography allows that limit to be found. Microfabricated quartz surfaces with concentric grooves and ridges constitute a simple system for investigating cell elasticity. These substrates, obtained by photolithography, have ridges and grooves with a width of 2 or 4 µm and a range of depths from 30 nm to 500 nm. The radius of curvature of the ridges varies across the quartz substrate testing cell elasticity under a range of conditions in one sample. When bone cells are grown on these surfaces they are found to assume different morphologies. Where the radius of curvature is high the cells adopt an elongated morphology (Figure 1b), following the ridge and groove structure. In contrast, where the radius of curvature is small the cells spread over the grooves and ridges (Figure 1a). Figure 2: Fluorescence images of actin fibers (green) of bone cells grown on concentric lines (a) close to and (b) far from the centre of the grooves. (c) cell nuclei aligned to the circular grooves and (d) triple fluorescence staining of cells far from the centre with actin in green, the nuclei in blue and focal points in red. In conclusion, groove microtopographies influence cell behavior in vitro. Future work will focus on deep microtopographies deeper than 500 nm and their influence on cell apoptosis. This may form the basis of a new strategy for the control of cell proliferation and death. This work was partly funded by the European Commission in the context of the Marie Curie research training network BioPolySurf (www.biopolysurf.net). CSEM thanks them for their support. Figure 1: Bone cells on concentric grooves with a high curvature (a) and with a low curvature (b). Cells spread and orient normally on the flat surface in the top left of b. In the bottom right the cells are elongated and align to the grooves and ridges. The cytoskeletal protein, actin, forms fibres that play a crucial role in cell spreading, movement and adhesion [3]. Immunofluorescence staining of actin fibres allows the study of the form and structure of adherent cells on quartz surfaces (Figure 2). The response of the cells seems to be linked to the rigidity of the actin fibres. Shallow grooves with a low curvature result in a partial alignment of the cells, which cross a few grooves only: the actin fibres are well aligned to the [1] F. Rehfeldt, A. Engler, A. Eckhardt, F. Ahmed, D. Discher, Cell responses to the mechanochemical microenvironment- Implications for regenerative medicine and drug delivery, Adv Drug Deliv Rev., 59, (2007)1329 [2] P. Kunzler, C. Huwiler, T. Drobek, J. Vörös, N. Spencer, Systematic study of osteoblast response to nanotopography by means of nanoparticle-density gradients, Biomaterials, 28, (2007) 5000 [3] C. Wilkinson, M. Riehle, M. Wood, J. Gallagher, A. Curtis, The use of materials patterned on nano-and micro-metric scale in cellular engineering, Materials Science and Engineering, 19, (2002) 263 59

Composite Materials for Bone Implants M. Giazzon, M. Liley, G. Weder CSEM is developing methods to nanostructure ( texture ) composite materials for use in orthopaedic implants. Photolithography and bead lithography methods are used to create master templates that are then replicated in a resin matrix. The structures will be tested for their effect on bone cells in vitro. The use of orthopaedic surgery to replace joints and repair bone defects is increasing rapidly. Due to a more active aging population, the demands made on the materials used in these operations are also increasing: improved robustness, longer lifetimes and easier surgical procedures are expected for hip implants and other joint replacements. Metals have been used with enormous success in orthopaedic surgery, but there are still some problems associated with their use. While issues such as weight and thermal conductivity can be important for specific applications such as cranial repair, one major issue of almost universal importance is that of Young s modulus. The high stiffness of metallic implants results in a mismatch in its mechanical properties and surrounding bone. This in turn leads to stress shielding : loss of bone mass and weakening of the surrounding bone that may lead to implant failure. In this context, the repair of osteoporotic bone remains a major challenge. As a partner in the EU project Newbone, CSEM is working to develop composite materials that can be used in orthopaedic surgery. Glass-fibre reinforced composites (FRCs) based on polymeric materials currently used in dentistry are being tested and optimised for applications in bone repair. CSEM s contribution is to test the effect of surface coatings and modification, with the goal of developing surface micro- and nanostructures that enhance cell growth, cell adhesion and the integration of the implant into the surrounding bone. integration. So, combinations of the individual structures that give the best results will also be tested. Figure 2: Pillar structures in a silicon master CSEM is also developing methods to determine the reaction of bone cells to structured surfaces. In addition to previously reported new methods to directly measure cell adhesion are being investigated. One of the most promising of these methods uses a specially adapted atomic force microscope (AFM) to measure the force necessary to pull individual cells from the surface (see Figure 3). Figure 1: Hemispherical pits fabricated by replication in a bis- GMA/TEGDMA resin matrix The micro- and nanostructures are fabricated in the surface of the resin composite matrix by replication. The original ( master ) structures are made by photolithography, in the case of microstructures (Figure 1), and bead lithography for the nanostructures (Figure 2). In a first stage, the two types of structures will be tested separately for their effect on cultured bone cell lines. Previous studies on dental implants have shown that multi-length scale topographies give the best bone Figure 3: Direct measurement of cell adhesion: a) A cell attached to an AFM cantilever is brought towards the surface. b) The cell contacts the surface. c) The cell is pulled away from the surface. The deflection of the cantilever is measured to determine the force applied to the cell. d) The cell is released from the surface. Initial results with this technique are promising, and it is hoped that it will give new insights into the influence of surface modification on the interactions between bone cells and surfaces. This work was partially financed by the European Commission in the context of the Project Newbone (NMP3-CT-2007-026279). CSEM thanks them for their support. 60

Simultaneous Detection of Four Antibiotic Families in Milk for Customer Safety G. Voirin, R. Ischer, S. Pasche A biosensor for the detection of four antibiotic families has been realized and tested with reference milk samples in collaboration with European partners. The simultaneous detection and identification of antibiotics in contaminated milk has been demonstrated. In the dairy industry, it is important to avoid contamination of milk with antibiotics which could modify the fermentation process of dairy products such as cheese or yogurt, or possibly cause allergic reactions in consumers (Figure 1). In the frame of the European project GoodFood [1], a biosensor system for the detection of several antibiotics has been developed in collaboration with other European partners. CSEM has focused on a biosensor detection system based on the interrogation of the resonance wavelength of a waveguide grating coupler (WIOS Wavelength Interrogated Optical Sensing). The relevant antibiotics were identified during a survey made in 30 countries around the world. Four antibiotic families were selected: sulphonamides, fluoroquinolones, beta-lactams and tetracyclines. Figure 1: Milk chain from production to consumer, screening test must be performed as early as possible The detection system is based on the change of the refractive index of the sensing surface due to the binding of molecules. The refractive index change induces a shift in the resonance wavelength of the waveguide grating coupler which is interrogated using a periodically swept tunable laser. This detection method is sensitive to refractive index changes on the order of 10-6, or the equivalent of several pg/mm 2 of molecules binding to the sensor surface. A competitive immunoassay format was chosen for the detection of the antibiotics. A specific sensing surface was obtained by using recognition molecules such as antibodies and receptors, developed by GoodFood partners. Specific antibodies for the sulphonamide and fluoroquinolone antibiotic families were obtained by immunization of rabbits, and are specific for a whole family of antibiotics (a family is a group of molecules with similar chemical structures). Receptor molecules specific for the beta-lactams and tetracycline antibiotic families were specially engineered to present a high affinity for a group of molecules. For each family, a test protocol was implemented on the biosensor platform and the cross reactions with the other reagents and antibiotics were tested. The goal was to obtain a biosensor platform with different sensing regions each specific to one antibiotic family, allowing detection in the different regions simultaneously with a unique milk sample. Using optical detection allows measurements on eight separate pads simultaneously. Figure 2 presents the calibration curves for each antibiotic resulting from competitive immunoassays. Figure 2: Calibration curves for sulphonamides, fluoroquinolones, beta-lactams and tetracyclines Validation of the detection system was performed in the laboratory of the Nestlé Research Center in Lausanne in the frame of a workshop where different methods developed in GoodFood were compared. Reference milk samples with known concentration of antibiotics were used for these tests. The response signal observed with the milk sample on the different reactive regions of the chip were compared to the value obtained with milk contaminated at the maximum residue limit level (MRL). Figure 3 displays the results obtained for the different reference milks, demonstrating that the four antibiotics can be detected at the MRL level. Figure 3: Measurement of different milk samples for the simultaneous detection of four antibiotics (dotted lines indicates signal at the MRL) In the frame of the GoodFood project, it was possible to develop a biosensor platform for the detection of four antibiotics families simultaneously at the maximum residue limit set in the legislation. Adapting this technology for Lab- On-a-Chip [2] will provide a tool for antibiotic screening at the farm level or before entering the dairy factory. This work was funded by SER, European Project FP6-IST-1-508774-IP and OFFT. CSEM thanks them for their support. [1] www.goodfood-project.org [2] G. Suárez, et al., Food Safety with the Help of a Miniaturized Laboratory, in this report, page 64 61

Smart Wound Dressing with Integrated Biosensors S. Pasche, R. Ischer, S. Angeloni, M. Liley, J. Luprano, G. Voirin Specific biosensors are being developed for the in situ monitoring of wound healing, focusing on ph measurements and on the detection of infection markers. Ambulatory, real-time monitoring will be made possible by integration of these sensors in wound dressings. Online health monitoring often requires hospitalization, which can become an expensive and inconvenient choice for the patient. In this perspective, wearable sensors that allow in situ biosensing without hospital surveillance constitute a very promising technology. The European project BIOTEX ( biosensing textile for health management ) [1] aims to integrate sensors in textiles for medical applications. The CSEM goal is to develop immunosensors for a continuous control of the wound healing process, which are based on ph changes, as well as on the concentration of an inflammatory protein, the C-reactive protein (CRP). Sensing principles include the use of responsive hydrogels that swell in response to changes in the environment (Figure 1a), and the use of functional surfaces that specifically recognize the target protein (Figure 1b). Swelling of ph-responsive hydrogels is a consequence of charging of the polymer chains that form the hydrogel. Functional surfaces rely on a dextran polymer layer (OptoDex ), which prevents non-specific adsorption from the biological medium and at the same time acts as covalent glue for immobilization of the receptor molecules. Reversible optical monitoring of hydrogel swelling with response to ph was demonstrated using a ph-responsive hydrogel (Figure 3a). The range of ph sensitivity can be tuned by changing the hydrogel chemistry. Monitoring of the concentration of CRP was performed using a specific surface chemistry with CRP receptors immobilized on dextran-coated waveguide chips (Figure 3b). a) b) Figure 1: Sensing principle for (a) a responsive hydrogel, and (b) a protein-selective surface Detection is based on an optical signal, using the evanescent field of light propagating along a waveguide, to probe refractive index changes. Both hydrogel swelling and biomolecule adsorption induce changes in the refractive index above the surface, which affect the propagation of the waveguide mode. An optical sensing system consisting of a white light source (LED) and a detection spectrometer, which can be easily integrated into a wound dressing patch, has been designed (Figure 2). Figure 3: In situ optical monitoring of (a) ph, using a ph-responsive hydrogel, and (b) changes in the concentration of CRP in serum, using a functional surface with immobilized CRP receptors. In situ measurements are possible after integration of the biosensor into a wearable sensing patch (< 0.2 cm 2 ) that is connected via optical fibers to the detection system and power supply (Figure 4). Figure 4: Sensing patch design to be later integrated in the wound dressing Figure 2: Optical detection scheme, comprising illumination with white light, light propagation along the waveguide, and wavelength detection with a spectrometer. This system allows in situ optical detection of volume changes of a hydrogel layer deposited on a waveguide substrate, with sensitivity better than 10-4 refractive index units, corresponding to polymer swelling on the order of 1% and to an adsorbed mass of ~100 pg/mm 2. The sensing patch will later be integrated into wound dressings or bandages, which will provide online information on the state of the wound healing process. This novel technology will be particularly valuable in applications such as the ambulatory supervision of skin grafts and ulcer treatments. This work is partly funded by the European Commission, FP6-IST-NMP-2-016789 and FP6-IST-026987. CSEM thanks them for their support. [1] www.biotex.eu.com 62

Biosensors for Drug Prevention B. Wenger, A.-M. Popa, S. Pasche, R. Pugin, G. Voirin The biosensing platform developed at CSEM is an attractive solution to detect illegal drugs and other substances concerning the security of citizens. However, to match the detection limits set by official authorities, the sensitivity must be improved. Therefore, an approach based on the nanostructuration of the sensing surfaces to increase the amount of analyte that can be trapped at the interface has been tested. A major issue in the security of public buildings and transport is the fast and specific identification of substances such as chemical and biological toxic agents, explosives and illegal drugs. Continuous monitoring of trace concentrations in conjunction with detoxification systems is envisioned to protect people from terrorist threats. The wavelengthinterrogated optical sensing (WIOS) system developed at CSEM offers the versatility to tackle several of these target analytes. find traces of illegal drugs in shipping containers. However, because of the very low volatility of this compound only traces are present in air. Therefore, lower detection limits are required. Although pre-concentration is feasible during the sampling step, improvement of the current platform is more desirable. One way to enhance the signal is to make the surface rougher in order to increase the amount of analyte that can be probed in the evanescent field of the guided light mode. As the penetration depth of the wave into the solution is less than 200 nm, nanostructures are required. As a first trial, mesoporous layers made of metal oxide nanoparticles (SiO2, AlOOH,...) were deposited and stabilized with a polymer. After functionalization, these layers showed enhanced detection sensitivities up to 3-5 times for model proteins. However, due to the size of the pores, the penetration of the proteins into the mesoporous network was slow and incomplete. The detection mechanism of this instrument is based on the measurement of a change of refractive index at the surface of a waveguide. Monochromatic light is coupled into and out of the waveguide through gratings and the laser is tuned in order to find the resonance wavelength corresponding to the given coupling angles and the effective index of the waveguide. The chips are usually functionalized with a specific biological receptor (e.g. antibodies) and adsorption kinetics are monitored in real time through a change in resonance wavelength. In this project, the functionalization of the surfaces was a result of the collaboration with external partners. Securetec Detektions-Systeme AG provided cocaine-binding antibodies and a hapten conjugate featuring several attached cocaine molecules. One of these substances is attached to the surface of the waveguide by means of a photo-crosslinkable polymer (OptoDex, Arrayon Biotechnologies) while the second is used in solution together with cocaine for competitive immunoassays (Figure 1). The second approach was to form nano-pillars and nanoholes in a thin silica layer deposited on top of the waveguide. An in-house procedure [1] based on block copolymer inverse micelles as templates was used (Figure 2). The depth of the features is typically up to 100 nm making the entire nanostructure accessible to the evanescent field of the guided light. Thus, the transducer surface area is drastically increased. Figure 2: Nano-pillars (right) and nano-holes (left) in SiO2 realised by etching on WIOS grating chips. Depth: ~80 nm, distance between pillars: ~200 nm. These roughened surfaces are currently under investigation. They will be optimized for the WIOS measurement system and the signal enhancement will be characterized This work was funded by the European Community via the Integrated Project NANOSECURE NMP3-CT-2007-026549. [1] S. Krishnamoorthy, et al., Langmuir, 22, (2006) 3450-3452 Figure 1: Competitive immunoassay for cocaine detection The detection limit for cocaine for this assay is around 100 ppb. A typical application of this technique would be to 63

Food Safety with the Help of a Miniaturized Laboratory G. Suárez, S. Pasche, R. Ischer, G. Voirin, N. Schmid, J. Auerswald A miniaturized laboratory, often referred to as a lab-on-a-chip, based on the Wavelength Interrogated Optical Sensing (WIOS) system has been developed for the simultaneous detection of several residual antibiotics in fresh milk. One of the major challenges in food safety is integrating quality control into the process of production and/or commercialization. Specifically, the analysis must be accurate, fast, cost-efficient, disposable and easy to operate by the nonskilled technician. In the milk industry in particular, levels of residues of veterinary medicinal products, of which antibiotics represent a significant part, are strictly regulated by the European Union legislation. More precisely, a series of four families of antibiotics are found to be of particular interest: lactams, tetracyclines, sulfonamides and fluoroquinolones. In the framework of this CCMX (Competence Centre for Materials Science and Technology) project, the side-by-side development of a label-free multidetection system and an integrated microfluidic cartridge converges to simultaneous and fast detection (< 15 min) of four antibiotics in the field environment. The label-free multidetection system is based on WIOS technology developed at CSEM and allows sensitive detection of biomolecules adsorbed on the waveguide chip. The selective adsorption of molecules from the solution induces a change of refractive index at the interface which is monitored. Competitive immunoassays based on the specificity of either antibodies or receptors have previously been developed for the simultaneous multi-detection of antibiotics and have been optimized in the framework of the European project GoodFood [1]. The other aspect of this work consists of developing and fabricating a microfluidic cartridge that integrates both the sensor chip and the reagents required for the assay. Currently the cartridge is fabricated from a piece of plastic (PMMA) of dimensions 10 x 4 x 0.7 cm in which channels and reservoirs are machined by micromilling. pressure. The basic idea behind the setup is to control which liquid (sample, buffers ) is driven through the cartridge channels by submitting its reservoir to the atmosphere while a negative pressure is applied at the other end of the cartridge. Moreover, the use of a 3-port valve on the pump allows for two possible pathways on the cartridge: the loading path (to deviate residual air from the sensing chip) and the sensing path which addresses the liquid to the sensing regions for reaction/measurement. Waste reservoirs ensure that no residual liquid goes out of the cartridge. With this simple setup neither the valve nor the pump are directly in contact with the solutions used during the assay; thus, no contamination occurs. Figure 2: Picture of the whole detection setup with microfluidic cartridge inserted into holder interface (grey box) The system (Figure 2) was tested successfully with spiked milk samples demonstrating the automated detection of two antibiotic families (sulfonamides and fluoroquinolones) (Figure 3). Prior to the analysis, a small volume of milk ( 1 ml) is introduced into a vial containing the assay reagents. The vial is closed with a rubber-cap and introduced upside down into the sample vial holder located on the microfluidic cartridge. Two needle-inlets on the base of the vial holder pierce the rubber-cap and connect the sample to the fluidic system. Figure 3: Typical signals obtained for antibiotics detection in milk This system that is currently under optimization for antibiotics detection in milk remains easily adaptable to further applications (eg. food analysis or biomedical diagnosis). Figure 1: Setup of the analysis system In terms of fluidics, the overall setup of Figure 1 is based on the use of a single syringe pump working in aspiration mode coupled with a multiposition valve connected to atmospheric This work was funded by CCMX-MMNS Lab-On-a-Chip project, European Project FP6-IST-1-508774-IP and OFFT. CSEM thanks them for their support. [1] G. Voirin, et al., Simultaneous Detection of Four Antibiotic Families in Milk for Customer Safety, in this report, page 61 www.goodfood-project.org 64

Wearable Biosensors in Protective Clothing G. Voirin, S. Pasche, R. Ischer, E. Scolan, M. Tormen, G. Dudnik, J. Luprano A non-invasive biosensor for the detection of stress markers, such as lactate in sweat, is being developed. This system will be directly integrated in the garment of professional rescuers and fire-fighters to improve the safety of these professionals during their intervention. In the European project BIOTEX [1], CSEM developed a miniaturized label-free biosensor system for application in wound dressing [2]. The European project PROETEX [3] aims at developing textile and fibre based, integrated, smart wearable sensors for emergency disaster intervention personnel with the goal of improving their safety, coordination and efficiency. A non-invasive, wearable biosensor is currently being developed for the detection of biological parameters in sweat. An examination into the needs of workers from the field of disaster management (town and forest fire-fighters, civil protection, etc.) has indicated the importance of controlling one s physiological stress during intervention under dangerous conditions such as heat, low visibility and a low oxygen. As the blood lactate level is a known indicator of physiological stress, the aim of this project is to develop a non-invasive biosensor that directly measures lactate levels in sweat. An initial biological detection system is based on responsive hydrogels that shrink or swell in response to an external stimulus (lactate concentration). The polymer chains of the hydrogel are functionalized with specific enzymes (lactate oxidase) that are incorporated before polymerisation. Conversion of lactate to pyruvate changes the ionic concentration in the hydrogel, which affects the hydrogel volume by an osmotic effect (Figure 1). Figure 2: Sensing principle and realized scheme using waveguide grating, lens and optical fiber In a second approach, the sensing layer is placed directly on optical fibres that can easily be integrated in a textile structure. In this case, a colorimetric approach was chosen using ph indicators incorporated in a sol-gel matrix that is deposited on the core of the optical fibre. Sensitivity to lactate is obtained by incorporating a specific enzyme in the sol-gel matrix. Preliminary results on the fabrication of ph sensitive sol-gel are shown in Figure 3. Figure 3: Color change of a ph sensitive sol-gel matrix exposed to different ph Figure 1: Swelling of an enzyme-responsive hydrogel due to an osmotic effect The volume change of the hydrogel directly translates into a change in refractive index that can be monitored with a label free optical biosensor based on the wavelength interrogation of a waveguide grating coupler. A miniaturized system comprising optical fibres, a lens and a waveguide grating will be integrated into a textile garment (Figure 2). A micro spectrometer based on a MEMS tunable grating [4] is presently being developed for detection of the wavelength shift; however, for initial tests, a commercial mini spectrometer has been used. The use of miniaturized biosensors allows their integration in textile garments for the non-invasive monitoring of a biological marker of stress directly in sweat. This next generation of smart garments will improve the safety of professional rescuers during dangerous intervention. This work is partly funded by the European Commission: project FP6-IST-026987. CSEM thanks them for their support. [1] www.biotex-eu.com [2] S. Pasche, Smart Wound Dressing with Integrated Biosensors, in this report, page 62 [3] www.proetex.org [4] M. Tormen, TUGON Compact MEMS-based Spectrometers for Infra-Red Spectroscopy, in this report, page 19 65

66

NANOMEDICINE Peter Seitz Mandated by the authorities of the Canton of the Grisons and the Principality of Liechtenstein, CSEM has carried out an indepth study of the feasibility of a new innovation center in the Alpine Rhine Valley, with the main objective of significant economic impact in this region. To this end, the new CSEM innovation center must build up activities and competencies in a domain where an already well-established regional industry cluster can be found, but for which CSEM has a lot of preexisting technologies and know-how to offer. In close collaboration with the regional industry, research organizations, universities and the political authorities, the novel and highly promising area of Nanomedicine has been selected. Since the Alpine Rhine Valley is already home to a substantial, successful MedTech cluster and CSEM has a rich portfolio of nanotechnological solutions to offer, Nanomedicine appears to be a natural choice. According to the European Science Foundation, Nanomedicine is defined as the science and technology for: Diagnosing, treating and preventing diseases and traumatic injury Relieving chronic and acute pain Improving and prolonging human health, through the use of molecular instruments and tools, and by understanding the functioning of the human body on the molecular level [1]. In short, Nanomedicine is Nano for Health. The driving force for the activities of CSEM is rarely scientific curiosity but most often the creation of huge economic impact through the development of products and services with significant value for large user communities. For this reason, a key question to be answered is whether Nanomedicine has the potential of making significant contributions to the future of health care. Due to the current vast demographic change (over-ageing population), large world-wide industrialization and growing expectations for a better quality of life in our society, health care costs are exploding. To moderate this development, the future of health care is envisaged to be heading in the direction of 4P medicine, which will be: Personalized, through the use of cost-effective, individual diagnosis, therapy and monitoring Predictive, by establishing and exploiting personal genome and health risk profiles Preventative, thanks to cost-effective screening, therapeutic and long-term observation methods (find-fightfollow) Participatory, by empowering the patient and her caregiver in clinical environments and at home. On-going research in Nanomedicine is targeting key elements of 4P medicine from low-cost gene profiling, over novel functional imaging methods for living cells, to miniaturized theranostic systems (integrated combinations of diagnostic and therapeutic devices) to contribute substantially to turning this vision into reality. Building on traditional strengths of CSEM, the particular contributions of the new CSEM Research Center for Nanomedicine in Landquart are foreseen in the following four areas: Functional nano-imaging, by exploiting element-sensitive X-ray techniques and advanced fluorescence microscopy methods for the acquisition of 2D and 3D images of living cells in real time and with sub-micrometer resolution. This will provide new insight into the functioning of cells under various conditions. Bio-selective surfaces, through the functionalization of metallic, dielectric, plastic and ceramic surfaces with organic or inorganic layers with application-specific properties, such as anti-bio-fouling or enhanced bone ingrowth. Versatile cell growth reactors, as major tools for toxicological tests of novel substances ( cytotox platform ) enabling significant reduction of animal testing, as well as for regenerative medicine, allowing the production of large quantities of differentiated cells from a small quantity of patient-supplied healthy cells. Robust medical sensing, with the aim of providing novel sensing principles and devices, capable of yielding reliable measurement results of critical vital parameters over long periods. This includes smart tubes for the sensitive and selective gas analysis in human breath, as well as EIT (electro-impedance-tomography) systems on various scales. The activities of the fledgling CSEM Research Center for Nanomedicine have already resulted in the creation of a first startup company, Dynetix AG, providing label-free bio-sensing solutions [2]. This has only been made possible through the support of other CSEM divisions, which provided key elements of the technology at Dynetix. True to its main mission, the CSEM Research Center for Nanomedicine has already started several applied research projects in the four domains summarized above with high potential for lasting economic impact in the Alpine Rhine Valley, through close collaborations with regional industrial partners, by providing SME with technological solutions and access to the vast R&D network at CSEM, as well as with the preparation of more startups to be created in the coming years. [1] European Science Foundation, Nanomedicine An EMRC Forward Look Report, ESF 2005 [2] Dynetix AG, http://www.dynetix.ch/ 67

Robust Label-Free Biosensor using BRIGHT [1] Technology M. Wiki, F. Kehl, P. Seitz Among the various biosensor technologies, optical biosensors are the most promising for cost-effective, sensitive and high-throughput biochemical screening. They can easily analyse the response of a biochemical binding event without the need of any fluorescent labels. The optimized BRIGHT technology fulfils the key requirements for optical biosensors, in particular sensor robustness and reduced time-to-result. The requirements of biosensor instruments for research and industrial needs today are copious, and a commercially successful system must be capable of meeting the expectations of a demanding user in the laboratory: Real-time and in situ monitoring Sensitive, stable and reproducible Detection technologies without the need of labels Reduction of cost, time and labor Based on its successful WIOS principle [2], CSEM has developed during the past two years its BRIGHT technology for use in label-free biosensor measurement systems. A series of recent improvements has led to the realization of an easy-to-use instrument, shown in Figures 1 and 2, providing fast and accurate multi-channel dynamic measurements in everyday lab use. Figure 2: Table-top label-free biosensor instrument BR-8 including temperature stabilization of the sensor chip SC-8. Figure 1: The BRIGHT technology is the basis of the versatile biosensor instrument BR-8 of the CSEM startup company Dynetix AG. The BRIGHT technology ( Bio-layer optical Resonance Interrogation for High Throughput ) allows sensitive, yet robust label-free measurement of association and dissociation rates, affinity constants, and determination of specificity of bioreactive molecules. In the development of the BRIGHT technology, great emphasis has been put on the expectations of a typical laboratory user, with the goal of making his daily work as simple, efficient and reliable as possible. Therefore, the main focus in the development of the BRIGHTbased biosensor instrument was its robustness, the significantly reduced signal drift, elimination of optical and electrical interferences, internal stray light rejection, as well as substantial improvements of the electronics, temperature stabilization, control software and signal processing algorithms for efficient elimination of cross talk between the different sensor channels. Due to these improvements at the heart of the BRIGHT technology, the long preparation time prior to a measurement has been reduced dramatically: In commercial systems of today, biosensor chips must often be prepared in advance and stabilized in buffer solution overnight. Conversely, BRIGHT technology reduces the preparation time to a fraction of an hour, as reported by external research institutes during tests. As a result, several consecutive measurements can now be performed within a short time, and long delays between measurements can be avoided, saving labor time and increasing throughput. The new biosensor system BR-8 allows the measurement of up to 8 channels simultaneously, with negligible crosstalk between the different channels. Measurements are carried out conveniently and reliably thanks to the disposable, versatile biosensor chip SC-8. Since no metals are used in the construction of the transparent SC-8 chip, interference with the biochemical reactions under investigation is eliminated. Due to the increasing demand for the BRIGHT-based, versatile biosensor instrument BR-8 by industrial and research laboratories, CSEM has created the startup DYNETIX AG [3] at its new Research Renter for Nanomedicine, in Landquart (GR) for the commercialization of the BR-8 instrument. [1] BRIGHT = Bio-layer optical Resonance Interrogation for High Throughput [2] WIOS = Wavelength interrogated integrated optical sensor [3] www.dynetix.ch 68

X-Ray Microscopy and Micrometer-Resolution Computer Tomography J. Nüesch, P. Seitz Recent advances in microfocus X-ray sources and high-sensitivity X-ray detection have revived interest in 2D and 3D non-destructive testing of optically opaque biological and technical samples, offering a geometrical resolution of down to micrometers in table-top instruments. Imaging with electromagnetic radiation in the soft and medium X-ray region (photon energies between 1-30 kev) is an excellent tool for the 2D and 3D investigation of optically opaque biological and technical samples. Recent advances in microfocus X-ray sources and high-sensitivity X-ray detection have made it possible to realize table-top instruments for nondestructive X-ray imaging with a geometrical resolution down to micrometers. This resolution makes it possible, among other things, to study the behavior of living cells, also in dense matrices of functional biological tissues. Of particular interest are the actions of osteoblasts and osteolcasts, the cells in the human body which build up and destroy bone material. A universal instrument, shown in Figure 1, has been realized with which X-ray images of small samples with a volume of less than 5 x 5 x 5 mm 3 can be acquired. Since the X-ray energy in the wide range of 1-100 kev can be computercontrolled, the acquisition conditions for maximum information-content of the signals, depending on the thickness, the density and the elemental composition of a sample can be optimized. shown in Figure 2. This allows not only placing the digital camera out of the direct X-ray beam, but the overall resolution of the system can be improved by using a geometrical magnification and by focusing on an inner plane of the scintillator, optimizing the contrast of the acquired images. Figure 2: X-ray detection sub-system, consisting of a scintillator platelet, a mirror and an ultra-low-noise digital camera with a highaperture (f/1.2) imaging lens. An example of a digital X-ray micrograph taken with an initial X-ray microscopy setup is shown in Figure 3. The object under study is a USB memory stick. The currently achieved lateral resolution is about 20 µm. Figure 1: Universal instrument for X-ray microscopy and Computer Tomography with micrometer resolution. The design makes use of a novel type of microfocus X-ray tube with a spot size of 3 µm. The magnification of the instrument is chosen with the mechanically adaptable constellation between X-ray spot, sample and detector subsystem. Since the sample is placed on a high-precision computer-controlled rotary table, the necessary data for 3D reconstruction of the sample volume, using the techniques of Computer Tomography (CT) can be acquired. Two different types of X-ray imaging systems are being used and investigated; both are based on a combination of highefficiency scintillating material and an ultra-low-noise solidstate digital camera. The first approach consists of gluing a thin (a few 100 µm thick) platelet of scintillating material directly on the image sensor. Since this complicates the cooling of the image sensor, the second approach is currently being concentrated on the optical imaging of the scintillator platelet using a mirror and a high-aperture objective (f/1.2), as Figure 3: X-ray micrograph of the USB memory stick offered by CSEM to their customers and partners The instrument is presently being improved by several means, to make it useful for biological samples, such as living cells, where a resolution of < 5 µm is required: Incorporation of a digital camera with more, smaller and lower-noise pixels, better focused optical imaging system with larger effective aperture, as well as enhanced shielding for reduced noise. 69

70

SYSTEMS ENGINEERING Mario El-Khoury Today, the genius of diverse technology integration and convergence enables many companies to offer innovative products and services to their customers. New telemedicine devices are regularly appearing. Such devices may for example, combine GPS, sensors and communication technologies to provide the users with better comfort and safety levels. In the consumer market, the Nintendo s Wii is becoming an all-time success-story thanks to the smart integration of motion sensors (accelerometers) in the remote controller. The main success factors are not the result of the vertical mastery of base technologies, but stem from the innovative combination and interaction of diverse but well known technologies. The challenges associated with such innovations include sensor fusion, miniaturisation, energy consumption, reliability and cost reduction. The Systems Engineering activity at CSEM is devoted to the applied research and development of innovative solutions involving the combination of multidisciplinary technologies, with a particular focus on: Portable monitoring devices Communication systems High precision mechatronic instrumentation In the portable monitoring devices field, CSEM has developed and delivered to the European Space Agency (ESA) a first prototype of a system that enables continuous monitoring of physiological parameters. The device is aimed at studying the adaptation of manned crews to extreme environments. It will be worn and tested by ESA personal at the Concordia station in Antarctica. During its validation test, the system proved to be comfortable to wear for 24 hours. In another application field and in the framework of a European project, CSEM is involved in the integration of wearable electronics and sensors in smart garments for helping rescuers during operations. Heterogeneous electronic subsystems have been developed, which reliably collect, synthesize and transmit the vital data and information to a remote station. A small and lightweight device was also developed by CSEM in 2008 for the wellness consumer-market. The device provides the users with a friendly feedback about their daily physical activities, and thus helps those reducing risk factors for chronic diseases and maintaining a healthy lifestyle. The activities in the communication-systems field were again focused on the one hand on Wireless Sensor Networks (WSN) especially for environmental monitoring, and on the other hand, on the emerging domain of Body Area Networks (BAN). CSEM has developed a self-organized, multi-hop network wireless sensor network, based on battery-powered sensor nodes (WiseNode concept). In the framework of a European project, this WSN is integrated in an infrastructure for the detection of forest fires and floods. Another CSEM WSN has been deployed on a cliff in the Swiss Alps, subject to rock falls. Monitoring is done by measuring the relative movement of rocks using extensometers. The system has been running without human intervention for more than a year and has confirmed its advantages compared to wired systems. It was easier to install and does not suffer from damage to the wires. The predicted battery life of the sensor nodes is up to 10 years. On the BAN side, a significant advance has been made in the realisation of the demonstrator of a FM Ultra Wideband (FM- UWB) transceiver. FM-UWB is a very promising solution for BAN systems because it combines the low power and high robustness of the UWB with the low-complexity of FM. In parallel, a dual-patch antenna has been developed optimised to UWB high-band systems (bandwidth from 5.5 to 9.7 GHz). The reconfigurability and the directivity of the antenna, which uses a RF-MEMS switch, offer interesting potentials for energy-saving BAN or WSN. In the Mechatronics field, CSEM has designed a new system for the Attitude Control of Satellites (ACS). In traditional ACS, the change in orientation of the satellite is performed through the acceleration of three independent reaction-wheels, or by applying torques on the gimbals holding three rapidly rotating wheels. The proposed new system uses a unique reaction sphere, magnetically levitated which can be accelerated around any 3D rotation axis. The torque required for this acceleration is exported to the satellite and is used to change its attitude, therefore providing the required 3D torque. Cost, footprint and weight are among the multiple advantages expected from the new design as compared to traditional ACS. 71

Micro-Vibration Analysis Setup for MEMS and MOEMS Characterization J.-M. Mayor, I. Kjelberg, P. Masa, J. Babarowski A new test station for the measurement of the resonance frequencies of micro-structures is presented. The vibrations are detected either along the optical direction or perpendicular to it. The absolute resonance frequency is measured with accuracy better than 5 ppm (changes to 1 ppm). In 2008, the station will be equipped with a climatic and a vacuum chamber to measure the samples in a controlled environment. and a rubidium stabilized clock, directly connected to the station. The probe laser wavelength is above 650 nm so that the color rendering of the microscope is not affected by the dichroic beam splitter in the observation path of the camera: any defect of the test sample is clearly recognizable on the display. The detection of the movement can be measured either along the optical direction (perpendicular to the wafer plane) or perpendicular to it (in the wafer plane). Figure 1: The test station with a 100 mm wafer Measurement of the resonance frequency of test samples with a high accuracy is required in order to ascertain mechanical properties of the materials used, for instance Young s modulus as a function of temperature. The need to have a reliable and cost-effective system suitable for operation in the clean room production area as quality control during the manufacturing process was recognized. Based on CSEM s development, the system was built by the company OCB (CH-Marin) with commercially available standard mechanical blocks so that any change of the optical configuration could easily be implemented (see Figure 1). Particular attention has been given to the mechanical rigidity of the system. Contrary to usual microscopes, where the fine adjustment is done by moving the whole optical system, here the fine adjustment is performed by a small vertical shift of the objective only. As a matter of fact, the stability of the observing system has been checked and found to be better than 1 nanometer in a one hour observing time. For this purpose, the method developed by P. Masa within the frame of the ENCODER project [1] was used. Microscope objectives with a magnifying power of 5 x, 10 x and 20 x and a working distance of 39 mm also allows the test of encapsulated microsystems. The working distance can be further enhanced with the use of commercially available relay lenses which permit operation of the measuring equipment when the test sample is in a vacuum or climatic chamber (to be developed in 2008). The investigated test structures are expected to have quality factors well above 1 000 therefore an excitation with amplitude in the nanometer range, obtained with only 1 V on a PZT stack actuator, will bring test structures into resonance with fully detectable movement signals. The frequency response can be obtained with a SRL lock-in, a HP spectrum analyzer For the detection of the movement in a horizontal plane the investigated part must have a sharp edge on which the laser beam is focused. Any movement of the edge will change the amount of light reflected or transmitted. For the detection along the optical axis a surface of reasonable optical quality is needed. Then an optical fiber is put at the image point of the laser spot. Any deviation in height will affect the size of the spot and thus the quantity of light transmitted into the optical fiber. With both configurations absolute resonance frequencies of test samples and of microsystem structures were determined with accuracy better than 5 ppm. Resonance frequency change (for instance with temperature) can be detected with a sensitivity down to 1 ppm by measuring the phase difference between the excitation and the position signal. Figure 2: Mechanical response of a microstructure after a shock As the optical signal is a direct position signal the station can monitor aperiodic movements as well. An example is depicted in Figure 2, where the microsystem was subjected to a shock by a mechanical impact on the sample holder. Two impacts corresponding to the moving part of the sample touching the mechanical stop, then coming back to the equilibrium position with oscillations at its resonance frequency can clearly be seen. The damping of the movement can be also determined. The equipment was financed by the Hans Wilsdorf foundation. CSEM thanks them for their support. [1] P. Masa, et al., Encoder Nanometric Optical Absolute Position Encoder, in this report, page 14 72

Clinical Validation Results of the Long-Term Medical Survey System O. Chételat, A. O'Hare, P. Pilloud, J-M. Koller, S. Droz, A. Ridolfi, P. Theurillat, P. Renevey, J. Solà I Caros, O. Grossenbacher The paper describes the clinical validation of a physiological multi-parameter monitoring system made by CSEM for ESA. Results of the validation showed that the system fulfils its purpose. The real conditions of the validation also hinted at further potential enhancements. The European Space Agency (ESA) commissioned CSEM to design, build, validate and deliver one fully operational ground prototype of a system (LTMS2) measuring physiological parameters. The system was shipped and will be used during 2008 at Concordia station (www.concordiastation.com) in Antarctica to study the physiological adaptation of manned crews to remote, isolated and extreme environments. The underlying long-term objective for ESA is to obtain experience in the field which will be used in preparing a possible manned mission to Mars around the year 2030. This paper describes the clinical validation of the system performed in December 2007 on volunteers at the Emergency Care Unit of the University Hospital of Bern (Inselspital). LTMS2 is composed of an ambulatory unit, a stationary unit and some accessories, as well as acquisition, processing, archiving, and visualization software. The ambulatory unit (see Figure 1) simultaneously measures in an unobtrusive, comfortable and modular way ECG (Electrocardiograph), respiration, pulse oximetry (at the earlobe or fingertip), activity/posture, core body temperature (at the armpit or ear canal) and blood pressure (with a cuff at the arm). The data is recorded for 24 hours while the subject performs his or her usual daily tasks. During setup or modification of the configuration, the signals can also be visualized online. Figure 2: The ambulatory unit electrode comprising analogue and digital electronics to measure ECG, impedance and activity The stationary unit measures the body weight and composition (fat mass, water and muscle mass). All data is transferred to a laptop where it is processed further to obtained secondary signals such as ECG parameters (heart rate, heart rate variability, ST-segment amplitude and duration, QT-index see Figure 3) or activity classification (resting, walking, running, lying or standing). All signals are then transferred to a database for storage where they can be remotely accessed by a medical doctor (MD). Special mechanisms ensure that no data can be lost, accidentally erased or viewed by unauthorized people. The visualization of the signals is multi-scale and several sessions can be displayed on the same time axis. Out-of-boundary sections for any signal are marked and can be quickly accessed. Figure 3: The different parameters of a typical ECG wave Figure 1: The ambulatory unit of the LTMS2 system The ambulatory unit integrates commercial sensors with CSEM technology. In particular, the electrode shown in Figure 2 is actually made of two active dry stainless steel electrodes measuring ECG and impedance, as well as an acceleration sensor (used for activity and noise removal). The data is digitalized in the electrode and transmitted to a centralized data logger. The LTMS2 system was designed, built and tested according to the European directive #93/42/ECC and follows the relevant medical standards, especially EN60601-1 and EN60601-2-47 for CSEM ECG electronics. However, the system is not CE marked (even though many of its components are), because the intended use is for clinical trials in Concordia. Nevertheless, after having obtained the ethical committee and Swissmedic authorizations, and fulfilled other requirements of the norm ISO14155, the system was clinically validated by Prof. Dr. MD S. Jakob at Bern hospital. The principle of the validation was to test the system on a few healthy volunteers in a controlled environment and to compare 73

the signals with a reference to standard hospital devices. In addition, the clinical validation was a final test by a third party to check that all variables are recorded, downloaded and displayed as described in the user manual, as well as to medically assess the ECG quality regarding the identification of the ECG P-, QRS-, and T-waves (see Figure 3). Figure 4 shows a typical display of signals measured during the clinical validation. The ECG P-, QRS-, and T-waves are clearly identified and the ST, QT, and QRS segment correctly marked. The figure also shows the heart rate, respiration rate, ST amplitude and duration, and the QT index. Figure 4: Typical signals obtained and visualized by the LTMS2 system (from the clinical validation) The validation was performed on three volunteers in three sessions of 18 hours and one of 24 hours. All sessions comprised normal daily activities such as office work, walking around, jogging and night sleeping. The validation clearly proved that the system is comfortable to wear for 24 hours and can record data for this period, process the data and visualize a large number of physiological parameters in perfect synchronism with time. The accuracy of the parameters does not, however, always match the reference. While the bias was negligible for heart rate, oxygen saturation and respiratory rate, LTMS2 underestimated temperature by 1 C and overestimated systolic and diastolic blood pressure by roughly 10 mmhg, and mean blood pressure by approximately 5 mmhg. The relatively bad accuracy of the blood pressure is surprising since for this parameter LTMS2 simply provides a digital interface to a CE-marked commercial device. Motion artifacts were sometimes a problem for oxygen saturation measurement. This is easily explained though: during the validation, the reference device was placed at the fingertip whereas the LTMS2 sensor was placed at the earlobe (less obtrusive but more subject to artifacts). A similar explanation holds for ECG and related parameters such as heart rate that are sometimes altered by artifacts. In this case, one has to take into account that the reference used a threelead system, while LTMS2 is limited to one lead. Cross checking between leads is therefore impossible in LTMS2, which increases the risk of being deceived by artifacts. In LTMS2, the activity signal is picked up at the electrode, while the reference used a watch-like device. Despite this location difference, LTMS2 and the reference device showed similar actigraphs. The activity and posture classification was in accordance with the situations specified by the experiment protocol (no reference was available for these parameters). In conclusion, the LTMS2 system has been proven operational in real conditions. Taking into account the differences between the location and technology used for the measuring of the physiological parameters, the LTMS2 system accuracy has been validated. However, a future enhanced version of the LTMS2 prototype should include additional means to automatically detect and reject more artifacts. Other foreseen improvements include more integration and accuracy, in particular for core body temperature, oxygen saturation and blood pressure. CSEM is already conducting research projects on these challenging topics. Many subsystems of LTMS2 released from some of the stringent requirements of the ESA needs can be readily converted to commercial applications in several domains, including physiological monitoring in sport and high-altitude activities, in firefighting and life-threatening situations, in home care and telemedicine, or in physiological studies. 74

ActiSmile A Portable Biofeedback Device on Physical Activity B. Gros, J. Solà I Caros, P. Theurillat, J. Krauss, U. Mäder, H. Buchholz Together with the Swiss Federal Office for Sports (BASPO) and the company ActiSmile SA CSEM has designed and developed a portable biofeedback device to continuously monitor the physical activity of its user. The key technology resides in sophisticated signal processing methods for multi-axis accelerometer sensor systems, including modern feature extraction, classification algorithms and low-power implementation on a realtime platform. Motion is an important modulator of vital human organic functions such as respiration, heart cycle, blood oxygen saturation. Physical activity is viewed as an important component of a healthy lifestyle and the relationship between physical activity and several known risk factors for chronic diseases are well-known. Important information about human health is expressed in human motion during day and night, such as the daily relative percentages of walking or running with respect to resting. These relative percentages can be used as indicators of potential psychological disorders or physiological pathologies. Accelerometry-based activity monitors are widely used to capture objective information on patterns and levels of physical activity. Although data collection is relatively easy, data reduction and data processing are challenging topics. The company ActiSmile SA has mandated CSEM to design, develop and implement a portable biofeedback device to continuously monitor and promote the physical activity of its user. The classification approach relies on the signals of a multi-axis acceleration sensor system which are projected to the breast vertical axis of the subject. Feature extraction is the essential part of the processing prior to any classification task. Features depend on the signals and the choice of a pertinent small size of feature set improves the intersubject classification accuracy. The design of the feature space in the classification machine takes into account the final desired low complexity algorithm in order to target a low-power and portable application on a real-time platform. For this reason, features derived from frequency or any other eigenfunction transformed domain has been eluded. An extensive study on the physiology of human motion has allowed the development of a new set of proprietary features derived from the temporal domain. The features are fed to classification stage. Being aware that the final applications may require different classification resolutions, a decision tree has been chosen as the most appropriate classification strategy. The ActiSmile device performs in real time the data acquisition, feature extraction, classification and high-level interpretation routine tasks. The output of the processing stage corresponds to an activity class tag (namely: lying, standing, walking, running), which is calculated every 5 seconds and stored within the FLASH memory of the portable ActiSmile device. A high-level interpretation algorithm calculates with the number of stored activity class tags the user feedback. A SMILEY is fed back and displayed on the LCD of the ActiSmile device, if the user has performed the defined minimal physical activity according to the guidelines of the World Health Organisation (WHO). Figure 1 shows the portable ActiSmile devices which are worn either with a clip on the thorax of the user or at the belt, or around the neck with a lanyard. The ActiSmile device can be recharged via a standard USB cable. Figure 1: Portable ActiSmile device with USB version (left) and wireless version (right). The transmission of the stored activity class tags to a data validation software can be performed either via an USB link or wireless with a Bluetooth version, as shown in Figure 1. The transmitted data can be validated under a Windows based data visualization and calibration software. The trends of the performed physical activity can be visualized on a daily, weekly and monthly basis as shown in the graph of Figure 2. Moreover, the data validation software provides a calibration tool to program and individualize the portable ActiSmile device with the personal data age, weight, sex and fitness level. The calculation of the SMILEY feedback is adapted accordingly. Figure 2: Windows based data visualization software, with the graph of the performed daily physical activity (x-axis: time; y-axis: percentage of performed physical activity). The verification of the correct interpretation of the performed physical activity with the ActiSmile devices has been validated by the Swiss Federal Office of Sports. A pre-series of the ActiSmile product was launched in October 2007 and a further product enhancement is planned during 2008. Institute of Sports Sciences, Federal Office of Sports (BASPO), CH-2532 Magglingen; (www.baspo.admin.ch) ActiSmile SA, Rathausstrasse CH-6340 Baar; (www.actismile.ch) 75

Prediction of Neurocardiovascular Events R. Vetter, N. Virag In order to improve acceptability and quality of life related to a medical diagnostic test, CSEM developed in a joint collaboration with Medtronic Europe a system based on computer supported prediction of the test outcome. The results of the retrospective study on 1155 patients are very promising and show that if the diagnostic test was stopped at the instant of event prediction only five percent of the patients would have had to experience the traumatic neuro-cardiovascular event associated with a positive test outcome. Patients with unexplained neuro-cardiovascular disorders often represent diagnostic dilemmas due to the difficulty to gather the pre-current signs of significant events. The rarity of such events brings about that limited time period monitoring using external Holter may be ineffective and not record the pre-current signs and cause of the disorders. More advanced monitoring devices such as implantable loop recorders may gather the pre-current signs and causes of the disorder but only if a dedicated automatic event detection exists. Nevertheless, such devices require invasive procedure and thus cause increased diagnostic costs. To approach this problem, diagnostic medicine designed dedicated experimental protocols which will provoke the specific neurocardiovascular events through external controlled stimulus and conditions. The inconvenience of these approaches consists in the fact that the patient has to experience the neuro-cardiovascular event during the diagnostic assessment. This is often traumatic and is a reason why some patients prefer not to undergo such a test. As an example, tilt table testing is recognized as a standard test to diagnose vasovagal syncope and establish the neurocardiovascular dysfunction. The test is illustrated in Figure 1. After 5 minutes supine rest, the patient is tilted to a 60 degree head-up position. If symptoms do not develop after 20 min of tilt, sublingual glyceryl trinitrate is administered to further provoke syncope. The test ends successfully if syncope develops or is stopped unsuccessfully after 35 min. Thus, each successful tilt test allowing an establishment of the neuro-cardiovascular dysfunction and yielding further medical insights ends with a traumatic fainting of the patient. In order to make this test more acceptable to the patient, shorten the tilt testing experience and decrease the diagnostic costs, a method which allows an early prediction of a successful outcome of the tilt test [1] has been developed. The algorithm exploits the trend of blood pressure, the trend of the heart rate and an indicator of the autonomic nervous modulation to continuously process a cumulative risk of the positive outcome of the tilt test. The algorithm yields an alert when a threshold is crossed. This suggests that the tilt table test will be positive, that syncope will occur in very soon and that the test should be stopped to avoid the traumatic experience of fainting for the patient. The performance of the algorithm was assessed on a large control database of 1155 patients where tilt table tests were conducted to their end. The successful outcome of the tilt table test was predicted in 719 of 759 patients (95%) whereas 29 false alarms were generated in 396 unsuccessful tilt table tests. On average the successful outcome was predicted 60 seconds before fainting leaving sufficient time to stop the experience before the traumatic outcome. In other words, if the test had been stopped at the alert processed by the computer, out of 759 patients only 40 patients would have had to experience the traumatic fainting experience engendered by vasovagal syncope while for 719 patients the establishment of the autonomic dysfunction would have been performed without traumatic psychological stress. The proposed system may open a novel area in diagnostic medicine where traumatic events due to systemic dysfunction would not have to be experienced to further establish and assess a pathological situation. The clinical validity of the proposed application of prediction of vasovagal syncope is limited due to the retrospective nature of the study. However, a prospective clinical study is currently being designed. In conclusion, computer supported sensing and processing of vital signals in a diagnostic protocol could increase the acceptability of the tilt test protocol and improve the patient quality of life. In medicine there are few parallels for which standard tests are replaced by mechanisms predicting outcomes midway through a laboratory study. The present development concerns a first step in such a process. Figure 1: Illustration of tilt table test setup used in medical diagnostic to establish neuro-cardiovascular dysfunction together with the developed system predicting the test outcome. The work was partly funded by the CTI Medtech Initiative and CSEM would like to thank them for their support. Swiss R&D Medtronic Europe [1] N. Virag, R. Sutton, R. Vetter, T. Markowitz, M. Erickson, Prediction of vasovagal syncope from heart rate and blood pressure trend and variability: Experience in 1,155 patients, Heart Rhythm, vol. pp. 1377-1382, November 2007. 76

Reaction Sphere for Attitude Control O. Chételat, L. Rossini, I. Kjelberg, S. Droz, L. Giriens, E. Onillon CSEM has developed a new concept for attitude control of satellites, within the frame of an ESA project, associated with Maxon, RUAG and HEVS. An Attitude Control System (ACS) traditionally needs a minimum of three reaction wheels. The orientation of the satellite can be changed by reaction at the acceleration of the appropriate wheel. Another traditional approach is to use a control moment gyro consisting of a rapidly rotating wheel held by gimbals. Applying torques on the gimbal joints changes the satellite orientation. The proposed approach is to use one unique reaction sphere playing both the role of reaction sphere and as the angular velocity of the sphere increases the role of control moment gyro. The sphere is held in position by magnetic levitation and can be accelerated about any rotation axis by a 3D motor. The torque required for this acceleration is exported to the satellite and is used to change its attitude. Thus, the reaction-gyro sphere is an actuator able to produce a 3D torque. The concept of reaction sphere is not new. However, the limitations of existing technologies and engineering capabilities have prevented reaction gyro spheres from being developed. The difficulty is clearly in the 3D motor, the magnetic bearing, and its combination. Recent advances in technology and especially in high-power Space-qualified processors give a totally new chance to the concept. A study has been performed to select the rotor and stator configurations. A synchronous motor configuration, with an 8 pole permanent rotor and a 20 pole stator has been selected, as depicted in Figure 1. A Matlab/Simulink model of the Reaction Sphere, based on the selected concept, has been developed. The model is based on a state space approach, the input of which being the 20 coils voltages and the outputs are the components of the torque vector. This model requires the calculation of the 3D motor constant (linking currents to force and current to toque) as a function of the sphere orientation. This model has been used to develop a control algorithm, based on PI controllers. A demonstrator is to be produced. The rotor will have an 89 mm radius and the external radius will be 103 mm. The demonstrator will be equipped with three position sensors from uepsilon, 3 force/torque sensors from Kistler and flux sensors. The flux sensor will be used to determine the sphere orientation. A custom electronic with 20 coil amplifiers will be developed to drive the Reaction Sphere, This amplifier also serves as the interface to a dspace 1005 board on which the control algorithm will be implemented. At the end of the year 2007, the design was finished and the building of the demonstrator is under progress within the frame of an ESA project that is to end in October 2008. Figure 2 presents a drawing of the demonstrator being built, with all its instrumentation around for its validation. The number of stator poles corresponds to a regular distribution of poles on a sphere, without singularities. The permanent-magnet motor has been selected for efficiency reasons, for the reduced complexity of its possible controller as well as its linearity (bearing and force control can be simply added). This concept has many advantages compared to others and an international patent application has been filed. Figure 2: Reaction Sphere demonstrator Figure 1: Selected configuration 77

Continuous Arterial Blood Pressure Monitoring: Can the Cuff Be Got Rid of? J. Solà I Caros A novel family of portable arterial blood pressure monitors is under development based on the multiparametric sensing of the cardiovascular function. Current status of research, initial experimental results and future guidelines are described here. In clinical practice, an ever-lasting technology in the assessment of arterial blood pressure dominates the landscape: the so-called auscultatory technique introduced in 1905 by Korotkoff: a well trained operator places a stethoscope over a distal artery and interprets the sequence of sounds that occur while a cuff placed above the artery is deflated. Although such an approach retains a secure position in the surgery, the occasional measurements taken in this manner can be unusually high (white coat effect) or low, leading to false diagnoses. Consequently some individuals may receive unneeded treatment and those actually needing it can be lulled into a false sense of well-being hence elevating their risk of cardiovascular disease. Alternatives to the auscultatory technique do exist in the field of ambulatory monitoring of blood pressure: most epidemiologic research studies rely on automatic inflation cuffs placed either over the brachial or radial arteries e.g. the devices that one might acquire in a pharmacy nowadays. Although relatively accurate, this so-called oscillometric technique does not match with the philosophy of portable continuous monitoring in two senses: on the one hand the measurement periodicity must be commonly set to 30 minutes because of the discomfort and pain associated with each inflation event, providing thus only a partial picture of the blood pressure evolution. On the other hand, each measurement alters the life-style of the user and thus modifies the blood pressure profile, especially at night. However, the need for a continuous cuff-less blood pressure monitor is continuously increasing in the fields of e.g. pharmacology, clinical practice and sports. A new family of cuff-less blood pressure monitors based on the optical and electrical sensing of a set of cardiovascular parameters is being explored at CSEM. The strategy consists of non-invasively tracking the evolution of those hemodynamic components that play a role in the establishment of the fluidic pressure in the arteries, and from them, obtain an indirect blood pressure estimate. From a fluidic perspective, two hemodynamic components must be considered: the cardiac output, i.e. the flow of blood from the left ventricle to the systemic vessels, and the total peripheral resistance i.e. the resistance, in a Poiseuille sense, that the systemic vessels oppose the cardiac output. The metrological strategies adapted inherit the know-how in multiparametric cardiovascular monitoring acquired during earlier research at CSEM. At the current stage an estimate of cardiac output is being assessed through the statistical signal processing of bioimpedance measurements. Bioimpedance depicts the measurement of the electrical potential differences that are generated across the thorax of an individual through the injection of low power AC currents on the skin surface. For the assessment of total peripheral resistance, a new approach based on the probabilistic information processing of infra-red tissue absorption and bioimpedance data has been developed and patented [1]. Both sensing techniques are inconspicuous and imperceptible by the subjects. The approach partly relies on the measurement of the wavefront propagation velocity of pulse waves through the arterial tree, the so-called pulse wave velocity. Figure 1 shows the results of an in-vivo study realized at CSEM labs. During the experiment, the mean arterial blood pressure of a subject was modified while several vital parameters were monitored with a reference device and the CSEM prototype. In this particular experiment the novel approach successfully tracked the variations of mean arterial blood pressure induced to the subject. MAP [mmhg] 160 140 120 100 80 60 CO [l/min] TPR [mmhg.s/ml] 8 6 4 2 1 0 0 5 10 15 20 Time [min] PORTAPRES CSEM Figure 1: Experimental dynamic cardiovascular responses estimated during a period of 25 minutes by a reference device (PORTAPRES) and CSEM technique. Returning to the initial question of being able to achieve continuous blood pressure monitoring without the cuff, the results obtained by CSEM biomedical sensing technology suggest this goal may be achieveable, at least under certain constraints. The research is still in progress. [1] J. Solà I Caros, Method for the continuous non-invasive and non-obstrusive monitoring of blood pressure, EP07123934.7, 2007 78

WISE Wireless Solutions for the Aeronautics Industry A. Hutter, B. Perrin, L. von Allmen, C. Kassapogou Faist This report is a summary of the work carried out under the European WISE project. This project investigates wireless solutions for the air industry. The focus of this article is on the evaluation and implementation of low-power protocols. The European WISE project [1] is a research activity that is intended to strengthen the competitiveness of the European air industry in the wireless domain. As such, the project investigates wireless technologies together with autonomous powering sources for aircraft sensing and monitoring systems. Industrial partners from the air industry include EUROCOPTER and DASSAULT as well as Messier-Bugatti and the EADS research centre. Within the project consortium CSEM is the expert partner for the following two domains: wireless solutions for difficult propagation environments low-power implementations for wireless solutions For the first domain, a magnetic solution for a wireless oxygen-bottle pressure-readout system has been designed and implemented. The major difficulty for this application was to guarantee transmission through metal shielding with only tiny holes. Concerning the second domain, CSEM expertise was required for the wireless replacement of the helicopter turbine air-intake temperature sensing system. The remainder of this article will focus on the description of this application and the implementation of the low-power wireless sensor. The investigated replacement system foresees a wireless sensor unit that is located at the bottom of the temperature rod in the engine compartment. To guarantee autonomous operation, the sensor is equipped with a magnetic microgenerator that exploits the vibrations of the helicopter. The micro-generator should deliver up to 10 mw continuously, which results in a maximum current constraint of 5 ma when operating at 2 V supply voltage. For the evaluation of the wireless transmission protocol options, a graphical user interface was developed, see also Figure 2. This tool allows the rapid visualisation of the impact of different protocol parameters. For the WISE application, a beacon-enabled network with a beacon interval of 491 ms was selected in order to guarantee the required delay constraints. Figure 2: Graphical user interface to evaluate protocol trade-offs Initial implementation results show that an average current of 1.7 ma is required for the transmission system, see also Figure 3. These initial results do not yet include the power consumption for the signal acquisition circuit. It is anticipated that the latter draws a maximum current of 1 ma, which results in an average current of 0.1 ma for 10% duty cycling (100 Hz sampling frequency). Therefore, with an estimated average current of 1.8 ma, which is equivalent to 3.6 mw@2v, it is expected to meet the power constraint originating from the micro-generator. Figure 1: Air-intake area of helicopter turbine and placement of the temperature sensor High precision temperature measurement (0.1 C) of the incoming air stream is required to guarantee optimum and efficient turbine operation. The current solution uses a PT100 temperature sensor located in the head of a rod placed inside the air-intake section of the turbine, see also Figure 1. The read-out electronics is placed in the engine compartment, where the temperature is relatively high. Due to the potential temperature variations along the cable, the measurement error can be higher than the required precision. Figure 3: Implementation results with signal acquisition emulation [1] Project web-site: www.wise-project.orghttp://www.wiseproject.org/ 79

UWB Antenna with Improved Bandwidth and Spatial Diversity using RF-MEMS Switches Q. Xu, L. Petit, J. R. Farserotu An UWB dual patch antenna with optimized bandwidth from 5.5 to 9.7 GHz was developed. Together with a RF MEMS based switch combining circuit, the UWB antenna allows construction of a reconfigurable unit that provides multiple-direction radiation. Within the project e-sense, CSEM has undertaken R&D on energy efficient FR solutions for Wireless Sensor Network (WSN). To successfully address the different scenarios and enhance the overall system performance, a very promising option is to add more functionality to the antenna subsystem, and focus on pattern reconfigurability of the UWB antennas. The motivations to address radiation pattern reconfigurability are the following: Range extension Direction Of Arrival (DOA) estimation Enhanced coexistence (Multiple users, multipath rejection) UWB antenna design a structure of stacked and notched dual-patch has been adopted to achieve the bandwidth enhancement. Parameters, including the size of the patches, the slot length, the microstrip feed position, the spacer thickness, as well as the dimensions of the notches, that impact the bandwidth performance have been optimized simultaneously in simulations. The enhanced impedance matching bandwidth ranging from 5.5 GHz to 9.7 GHz has been achieved and has shown good agreement with measured results (Figure 1). circuitry). Because of the particular nature of RF MEMS devices, which are electrostatic actuated micro electromechanical (MEMS) structures, the design, assembly and test of the RF-MEMS based circuit has been undertaken taking into account consideration for handling (Electrostatic Discharge (ESD) sensitivity) and assembly (ultrasonic cleaning/mechanical vibration sensitivity). The designed RF- MEMS based switch combining circuit showed very good isolation between the different antenna ports for higher diversity efficiency along with very low power consumption. Measured radiation patterns of the UWB antenna array using the RF-MEMS switch combing circuit are shown on Figure 3. Figure 2: Left - Switch combining circuit. Right - mounted antennas 0-5 Measurement Theoretical computation 330 0 0 [db] -10 30-10 300-20 60 S11 Mag [db] -15-20 270-30 -40 90-25 -30 240 120-35 4 5 6 7 8 9 10 11 12 Frequency [GHz] Figure 1: Measured and simulated impedance bandwidth RF-MEMS combining circuit a switch combining circuit has been developed and is presented in Figure 2. RF MEMS for reconfigurable antennas and beam forming networks (BFN) exhibit outstanding performances in terms of linearity, low power consumption and RF performances. The combination of several UWB antennas with a RF-MEMS switch based feed network in order to achieve both spatial diversity and powerefficiency at UWB frequencies has thus been addressed. The antennas and the switch combining circuit have been designed, tested and optimized separately. This solution has more flexibility in terms of the gain and the pointing directions. The circuit by itself consists of three cascaded COTS RF- MEMS devices as well as associated components (bias resistance, feed capacitance, charge pump capacitance, logic 210 180 150Antenna3-on Antenna4-on Figure 3: Achieved two radiation directions using RF-MEMS Conclusion - An UWB dual patch antenna with optimized bandwidth was developed. The enhanced bandwidth from 5.5 to 9.7 GHz covers the frequency band required by communications using UWB in the high band. The antenna diversity providing two beams enabled by a RF-MEMS switch has been demonstrated. The reconfigurability and the directivity of the antenna offer interesting potentials for energy-saving in a simultaneous communication scenario of WSN. This work was partly funded by IST project e-sense. CSEM thanks them for their support. 80

FM-UWB A Low Data Rate (LDR) UWB Approach with Short Synchronization Time and Robustness to Interference and Frequency-Selective Multipath J. F. M. Gerrits, J. R. Farserotu, M. Hübner, J. Ayadi Constant-envelope FM-UWB is a true LDR (< 100 kbit/s) UWB system. Instantaneous despreading in the receiver allows for rapid synchronization. The robustness to interference and frequency-selective multipath make this system a good choice for robust LDR Body Area Network systems. Ultra Wideband (UWB) communications are poised to enable short-range applications, such as remote health monitoring (ehealth) and home or office automation. Body Area Networks (BANs) [1] are potential candidates for UWB since the low radiated power of the UWB transmitter enables low DC power consumption yielding long battery life and the possibility to use energy scavenging. Size and cost constraints require a low-complexity approach that allows multiple users sharing the same RF bandwidth, and offers robustness to interference and frequency-selective multipath propagation conditions. Constant-envelope FM-UWB uses double FM: binary FSK followed by high modulation index analog FM implementing analog spreading. The FM-UWB signal is characterized by a flat spectrum and steep spectral roll-off. Due to the instantaneous despreading in the receiver, synchronization time is limited only by the bit synchronizer in the FSK demodulator. Figure 1 shows measurement results taken in a 62.5 kbps FM-UWB system operating at 4 GHz. Transmission starts at the rising edge of the TX_ENABLE signal. On the receiver side, the raw data RXD is available almost instantaneously, whereas the bit synchronizer circuit determines the overall receiver synchronization time. From a synchronization point of view, the FM-UWB system behaves like a narrowband FSK system. show that Impulse Radio and MBOFDM interference up to 15 db stronger than the FM-UWB signal can be dealt with. FM-UWB signals are robust to frequency-selective multipath [2]. Figure 2 shows MATLAB simulation results of the RF sensitivity improvement for 1000 realizations of the IEEE CM4 (strong non line-of-sight) channel. The graph in the upper part of the figure shows the RF sensitivity improvement for each channel realization. The histogram in the lower part of the figure shows the distribution of the receiver sensitivity improvement. The average and median value both equal 0 db meaning that 50% of the strong non line-of-sight channels yield a performance improvement. The worst-case sensitivity degradation is only 2.5 db. Straightforward by its principles, FM-UWB constitutes a LDR UWB communication system highly robust to interferences and multipath. Figure 2: Sensitivity improvement in CM4 channel. Figure 1: Measured FM-UWB receiver synchronization time. Interference from in-band UWB users benefits from the receiver processing gain which is equal to the ratio of RF and subcarrier bandwidth G PdB = 10 log 10 B B RF SUB = 10 log 10 2Δf RF ( β + ) SUB 1 R In a 100 kbit/s LDR system with a RF bandwidth of 500 MHz a processing gain of 34 db is obtained. As a result a 100 kbps FM-UWB radio can tolerate a 21 db stronger FM-UWB interferer. Simulations have confirmed these values and also [1] J. F. M. Gerrits, J. R. Farserotu, "FM-UWB: A Low Complexity Constant Envelope LDR UWB Communication System", IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs), July 2007, San Francisco, California, USA, IEEE802.15-07-0778-040ban, http://www.ieee802.org/15/pub/sgmban.htm [2] J. F. M. Gerrits, J. R. Farserotu, J.R. Long, "Multipath Behavior of FM-UWB Signals", Proceedings of ICUWB2007, Singapore, September 2007 http://www.wise-project.org/ 81

A Wireless Sensor Network for Fire and Flood Detection at the Wild and-urban Interface C. Kassapoglou Faist, P. Nussbaum CSEM develops a wireless sensor network as part of a sensing and computing infrastructure for the detection and assistance in crisis management during natural hazards (forest fires and floods). Vision sensors as well as low-cost, in-field sensing elements are integrated in the network. In spite of all technical progress mankind has achieved, natural hazards escape its control. Nonetheless, early detection, combined with genuine crisis management are essential in limiting the extent of disaster. The ability to monitor the evolution of relevant physical quantities throughout an area is a key element in this respect and, in the last few years, wireless sensor network technology has rendered this task feasible and affordable. CSEM, active in this field, participates in the EU project SCIER, which aims to improve the design and realization of a sensing and computing infrastructure for environmental risks, particularly focusing on forest fires and floods. The project combines wireless network technology with data fusion schemes and environmental models in order to provide an end-to-end system that detects the occurrence of a natural hazard and supports the authorities during intervention. Its user requirements are tailored on the problematics of the wild and-urban interface (areas at the border of urban zones, where isolated properties intermix with wild land). SCIER involves both publicly and privately owned equipment, offering to landlords the opportunity to subscribe in fast, localized alerts. Chipcon CC1100 radio transceiver. Since the batteries are to last for months or even years, the node design follows severe energy-saving techniques: multi-hop communication, use of energy-efficient protocols and in particular the CSEM WiseMac TM, operation in duty cycles with the nodes put in sleep mode most of the time. In SCIER, the deployed nodes are fixed, but the sensor network must support the hot deployment of new nodes (during a crisis, for instance) or the loss of some of its nodes (which may be a significant piece of information). The in-filed sensing elements are relatively cheap, commercial components. The Davis anemometer is used for wind speed and direction, the Davis and Technoline WS9004IT rain collectors for rainfall levels, the Sensirion SHT11 for temperature and relative-humidity measurements. The latter was assessed at controlled fire experiments that were conducted within a wind tunnel at MAICh, in Greece. The nodes are packaged in watertight, UV-resistant boxes for protection against natural elements, with the sensors fixed outside the box. An important innovation feature in SCIER is the integration of vision sensors in the wireless sensor network. Vision sensors are dedicated to monitor the field in order to detect an event and report on this result (a feature). Among the different possible events, occurrence of smoke by day and flame by night have been selected (Figure 2). A spatial correspondence between the detected events and the location will be implemented to enable data fusion at sensor level. Figure 1: SCIER sensing system The sensing system is composed of in-field as well as out-offield, vision sensors (Figure 1). They are spread throughout the monitored area and periodically report measurements that are collected through a number of access points (private or public) and reach the computing subsystem. This information is subsequently assessed, stored and processed by data fusion schemes, in order to decide whether anything is abnormal. In case of hazard detection, alarms are issued, both to the public authorities and to local property owners, and execution of the appropriate environmental models is triggered, in order to predict the evolution of the hazard and other related risks. Possibly, the density of sensors is increased through new deployments during the crisis. The environmental models are fed with geographic information from the SCIER GIS component and periodically confront their prediction to actual measurements provided by the sensors. CSEM is responsible for the sensing system. Battery-powered sensor nodes form a self-organized, multi-hop network. They are composed of a few sensing elements and a wireless communication unit, developed at CSEM (WiseNode TM concept) and based on a MSP430 micro-controller and a Figure 2: Vision sensor firmware architecture Development of the SCIER sensing system is about to be completed, offering a low-cost solution for the collection of spatially distributed information. In 2008, the SCIER concept as a whole will be tested at full-scale field trials in Portugal, France, the Czech Republic and Greece. The project partners are Epsilon International SA (GR), National and Kapodistrian University of Athens (GR), DHI Hydroinform A.S. (CZ), National Agricultural Research Foundation (GR), CSEM (CH), Group 4 Security Services (GB), Greek Research and Technology Network (GR), Centre d'essais et de Recherche de l'entente (FR), TECNOMA S.A. (ES), Associação para o Desenvolvimento da Aerodinâmica Industrial (PT). 82

Exploiting Directive Antennas for Wireless Sensor Networks L. von Allmen, P. Dallemagne, Q. Xu, J. R. Farserotu CSEM identified and characterized a number of applications using wireless sensor networks that would benefit from directive antennas. The goal is to reduce the power consumption of the communication system, while preserving or even improving the quality of service. CSEM is investigating energy saving techniques using directive antennas for wireless communication devices [1] in specific applications. The use of directive antennas offers the potential for improved overall system performance. For example, one measure of performance is the environmental impact of the radio-communication system, which may be reduced by lowering the emissions, which in turn translates into power savings, as well as, improved coexistence. Further, the use of directive antennas offers the potential for reducing the overall power consumption of the communication system; especially, in high density networks, where the number of transmitting devices can be large. Reducing the radiated power also improves spatial re-use, global reduction of the electro-smog and implicit improvement of the end user privacy by focusing and segmentation. Ultimately, this relates to the broadening of the concept of quality of service by involving factors like environmental-friendliness, compliance to more stringent standards related to communication as well as safety and operational conditions, or even transparency to the user. In radio communication systems, energy may be wasted in the following situations, some of which directional antennas can help mitigate: Idle listening A node is turning on its radio to listen, but there is no transmitter in the receiving range. Directional antennas do not bring a solution to idle listening. In fact this could even make the situation worse if there is no way to change the beam orientation when the antenna is incorrectly oriented (pointing to an area without nodes). Crying in the wilderness A node is sending when there is no destination present. This cannot be solved by smart antennas. Overhearing A node receives a radio signal but the content is not addressed to it. In this case smart antennas will reduce overhearing. Collisions Smart antennas could offer an improvement in the case where collisions occur between traffic from pair-wise communications; i.e. the traffic between A and B is in collision with the traffic between C and D. With directive antennas, the benefitt is due to improved spatial usage. Range To reach long range requires more energy than short distance to transmit information with the same quality. In this situation, adaptable directive antennas, in combination with a suitable MAC protocol, can enhance performance by concentrating the energy in the direction of the destination. As such, for the same radio energy consumption, radio directional antennas yield a longer range. Potential applications that can benefit from using directional antennas are (names are taken from the terminology defined in the IST project e-sense): Wireless hospital Sub-network interconnection Store of the future Entertainment In order to identify applications that would benefit from directive antennas, the study considered the scenarios (see Figure 1) elaborated within the e-sense project. Figure 1: Application spaces, Use Cases, Applications and Scenarios within e-sense Each scenario has been analyzed with regards to the applicability and potential benefits of using directional antennas. The analysis highlighted for instance that scenarios involving mobility during communication are difficult if not impossible to benefit from directional antennas. However, the use of directional and automatically reconfigurable (smart) antennas would help in this regard. The analysis has also shown that in applications where directional antennas add benefits, the main benefits expected are: Energy use improvement on both terminal and base Spatial reuse and system capacity improvement Extension of range Another point linked to the use of directional antennas is the need for dedicated or modified MAC (Medium Access Control) protocols (i.e., for adaptation and control of directivity). The study added a review of the state of the art and a classification of MAC protocols using directional antennas. This work classifies the typical MAC protocol algorithms with respect to the constraints and specifics brought by directional antennas, so that the most adequate algorithm can be chosen given the application properties. This work was partly funded by IST project e-sense. CSEM thanks them for their support. [1] Q. Xu, et al., UWB Antenna with Improved Bandwidth and Spatial Diversity using RF-MEMS Switches, in this report, page 80 83

A MAC Protocol for UWB-IR Wireless Sensor Networks J. Rousselot, A. El-Hoiydi, J.-D. Decotignie WideMac, a novel MAC protocol designed for wireless sensor networks using ultra wide band impulse radio transceivers, is compared with state of the art low power protocols. It compares favourably with the best while offering additional services such as rapid discovery of neighbors and positioning. These features are of high interest for distributed routing and for mobility enabled networks. Furthermore, contrary to the best known protocols, it operates without requiring special modulation types. Wireless sensor networks (WSN) are collections of small electronic devices which communicate together wirelessly and are equipped with one or more sensors, whose choice depends on the application domain. They are often deployed in environmental monitoring scenarios and must be able to run on battery for months or years. The management of the radio transceiver performed by the Medium Access Control protocol has an important impact on power consumption. Remarkably, it is the only one to reach this efficiency without a modification of the modulation scheme. Ultra Wide Band Impulse Radio (UWB-IR) is a communication technique based on a time-domain approach. It offers robustness to multipath propagation and to multi user interference and allows accurate ranging. These properties, associated with ultra low power consumption, make UWB-IR a good candidate for WSN platforms. Numerous low power Medium Access Control (MAC) protocols for WSN have been proposed in the last few years. All attempt to reduce four sources of energy waste: collisions, overhearing, idle listening and overhead. Introducing an UWB- IR physical layer has an impact on MAC protocol power consumption and may even make some implementations unusables. For example, the detection of an ongoing transmission poses challenges with respect to implementation with a UWB-IR radio. The best low-power MAC protocols therefore require a modification of the UWB-IR modulation to enable effective operation. Figure 2: WideMac power consumption WideMac also offers unique additional capabilities such as rapid discovery of neighbours, ranging and positioning. This is of special interest for distributed networks which require ad hoc routing, and for mobility enabled networks such as large scale environmental monitoring, herd control, vehicles tracking, warehouse inventory or elderly care. Figure 1: WideMac operation WideMac is a novel MAC protocol designed specifically for UWB-IR sensor networks. It operates as follows: each node periodically transmits a beacon message announcing its presence, and then listens for a brief period of time to detect any incoming transmission. A node with a message to transmit first listens until it receives the beacon of the destination node, after which it can safely transmit the message. The next time a message must be exchanged between the two nodes, the time spent listening for the beacon message can be greatly reduced because the destination wake up time will be known. Figure 1 illustrates the operation principle of WideMac. WideMac power consumption was compared with state of the art WSN MAC protocols (WiseMac and optimal preamble sampling, SCP-Mac, Crankshaft) using mathematical models. The results presented in Figure 2 show that WideMac was able to match the performance of the best known protocols. 84

Optimum Operating Regimes for Wireless Sensor Networks A. El-Hoiydi, J. Rousselot, J.-D. Decotignie Wireless sensor networks are used in applications that have constraints in terms of metrics such as timeliness, lifetime and reliability. The WSN designer needs to find a solution that meets the required objective metrics. Most of the time, applications have sets of objective metric values, depending on the operating regime. This can be exploited to find a better solution to the needs by trading one objective value against another. This study explores the potential of tuning in a combined manner the parameters of protocol stacks to achieve the best performance trade-off. Although low power operation is often quoted as the main quality of Wireless Sensor Networks (WSNs), such networks may also need to satisfy other goals, depending on the operating regime of the applications. For instance, a fire detection application in a Mediterranean country may privilege battery life in the winter when fires are unlikely. However, when some humidity and temperature conditions are met, the same application would place the priority on reactivity or timeliness with respect to the propagation of the information. This study shows the potential of tuning key protocol parameters in order to achieve the best possible compromise between operationally dependent and potentially divergent performance metrics. The objective is to optimize the operations of the WSN at run time. In WSNs, three key performance metrics have been identified [1] : timeliness which refers to the time to transport some information from its source to its destination, reliability which is the probability that a packet emanating from a source is eventually received at its destination, and lifetime which is the duration during which the network will operate continuously Energy (J) 2.5 2 1.5 3 x 104 The main question is whether there is a value of the transmitted power that leads to a better trade-off between consumption and latency. Power consumption and latency have been evaluated by simulation (OMNET++) using a IEEE 802.15.4 radio (Chipcon CC2420), a contention MAC with ideal wake-up scheme and routes generated by the Dijsktra algorithm. The network has 120 nodes distributed over a field of 300 x 300m. One of the nodes, the sink, collects messages sent by all other nodes. Figure 1 shows the total energy required to forward all generated packets to the sink (upper graph) and the average end-to-end latency experienced by those packets (lower graph). Every different random position of the nodes results in different blue curves. The red solid line curves represent the average over all random positions. From the curves, it is clear that with the CC2420 chip, there is no trade-off to make (at least in low traffic situation) with the choice of the transmit power. The maximum output power provides the best results both in terms of consumed energy and in terms of latency. The potential advantage of using multiple-hops to reduce the consumed energy is not present with the CC2420 because of its high base current consumption (8 ma in transmit mode and 18 ma in receive mode). If this radio had a base current consumption of 2 ma both in receive and transmit mode, the latency versus energy curve would be as illustrated in Figure 2. In this case, latency and energy could be traded. Latency (ms) 1 0.5-10 -5 0 5 10 Tx Power 12 10 8 6 4 2 0-10 -5 0 5 10 Tx Power Figure 1: Total required energy and average latency with a varying transmit power (CC2420 transceiver) Emission power is one of the parameters that impact several communication layers and may be tuned to look for the best tradeoff between some of the metrics. It is controlled by the physical layer, influences the link layer for instance by changing the collision probability and impacts routing because the number of direct neighbors and paths will change with the power. Intuitively, the higher the power the higher the consumption and the lower the latency (end-to-end delay). Latency (ms) 12 10-10 -9 8-8 -7 6-6 -5-4 4-3 -2-1 0 1 2 2 3 4 5 7 6 8910 0 4000 4500 5000 5500 6000 6500 Energy (J) Figure 2: Latency versus Energy when varying the transmit power (hypothetical transceiver) An additional degree of optimisation in WSNs may be reached by run-time tuning of certain protocol parameters in order to tailor them to the application needs. CSEM has shown here that there is potential tradeoff between reactivity and consumption by tuning the transmitted power if the base consumption can be reduced. Other parameters are under investigation under the IST WASP project. [1] IST-034963 WASP Project, Deliverable D4.2, http://www.wasp-project.org/ 85

Wireless Sensor Networks for Monitoring Cliffs in the Alps A. El-Hoiydi, J.-D. Decotignie In November 2006, CSEM in collaboration with CREALP and MAD technologies installed a wireless sensor network to monitor rock movements on a cliff near Sion. Since then, it has been running without interruption and without battery change. This report describes the settings and the intermediate results of this experiment. Wireless sensor networks find natural application areas in the domain of environmental sensing. In such networks, sensors are connected to small battery powered nodes that include a CPU and radio transceiver. The information sensed on the node is transmitted to a sink node that is often connected to some infrastructure (GSM, LAN,...). CSEM, like many other institutes, has deployed such applications for short-term experiments. In this report, CSEM presents results of one of the first long-term experiments without human intervention. reasons, the existing monitoring installation was maintained during the test phase. A new set of 3 extensometers has been installed. Each accelerometer is connected to a wireless sensor network node (Figure 2). Due to the propagation conditions, an additional node is used as a relay between the sensors and the sink node that collects all the measurements. Each sensor node is built around the Xemics XE88LC05 processor and a radio module based on the XE1203 transceiver operating in the 868 MHz band. The protocol stack includes Wisemac, a simple dynamically built routing protocol and clock synchronisation. Wisemac is an ultra low power contention medium access control based on an adaptive preamble sampling technique [1] developed at CSEM under the Wisenet TM project. Nodes and sensors are powered by a single 20 A.h Li Battery. Every minute each sensor node transmits the reading of the extensometer and the local temperature (used for compensation) to the sink node (Figure 3). Battery voltage and other statistics are also sent regularly. Figure 1 shows the routes (from the nodes to the sink) that were found best by the routing algorithm. Position [mm] Figure 1: The Chandoline site with the sensor locations The selected site is a cliff in the vicinity of the city of Sion in the Swiss Alps. The cliff is under observation because numerous rocks have fallen, jeopardizing an industrial zone located at the bottom of the cliff (Figure 1). Monitoring is done by measuring the relative movement of rocks using extensometers. Temperature Figure 3: Plot of the sensor measurements over a week The system has been running without human intervention for more than a year. Measurements match those captured by the pre-existing installation. This shows that such a system offers a viable solution. Compared to wired systems, it is easier to install and does not suffer from potential damage to the wires. The predicted battery life is around 10 years for the sensor nodes but less for the relay and the sink node. Long term campaigns in isolated locations are possible. Figure 2: An open sensor node with the extensometer [1] A. El-Hoiydi, et al., WiseMAC: An Ultra Low Power MAC Protocol for Multi-hop Wireless Sensor Networks, ALGOSENSORS 2004, 18-31 The site was originally equipped with extensometers wired to a central monitoring station at the top of the cliff. For security 86

Control Electronics for Bio-Sensing Textiles to Support Health Management B. Gros, J. Luprano, J.-A. Porchet, R. Rusconi, A. De Sousa, A. Ridolfi, J. Solà I Caros A versatile portable data acquisition device has been designed in the frame of the BIOTEX project in order to acquire and process the data of innovative sensors integrated in textile for the measurement of several parameters in sweat and blood. The European research project BIOTEX [1] is aimed at the development of biochemical-sensing techniques for health monitoring, compatible with the integration into textiles. For that purpose several sensing textile patches have been developed by the project consortium in order to monitor physiological parameters in body fluids such as sweat and blood. To evaluate the correct operation of such sensors, three main applications have been selected: (1) metabolic disorders in diabetes, (2) obese children and sports, and (3) sore monitoring/wound healing (Table 1). Applications Sensing method In sweat In blood/plasma Sports Optical SpO2 spectroscopy Wound Optical immunosensor ph CRP Sports Optical ph colorimetry Sports Impedance Conductivity Diabetes Wound Sports Capacitance Sweat rate Diabetes Sports Electrochemical Electrolytes concentration Table 1: Sensing methods referenced to targeted applications One of the main tasks of CSEM in the project was the development of a lightweight portable control electronics (Figure 1) able to acquire and process all sensor signals for the different BIOTEX applications. high resolution color LCD is used and together with its layer sensitive to the pressure of the fingers (touch screen) allows the user to press the virtual buttons displayed on the screen to navigate through the menus. The control unit can be customized to a specific application by changing a dedicated sensor board. This makes the unit highly configurable and reusable as a versatile mobile platform for other applications with other sensor data. The unit provides an optical connector for the SpO2 sensor, also developed at CSEM. The SpO2 sensor uses an innovative approach for the photoplethysmographic measurement at the thorax by using a set of plastic optical fibers to capture the light and the signal of which is transmitted to the remote light sensor, integrated in the control unit. These fibers are woven using conventional textile techniques (Figure 2) and can thus be integrated into garments. Figure 2: Woven optical fibers used for the SpO2 sensor Figure 1: Portable control unit The digital section of the portable control unit is built around a power-efficient ARM7 microprocessor. A removable miniature memory card (SDcard) stores up to 2 GBytes of data that can be downloaded to a PC by using a standard USB card reader. An integrated Bluetooth module provides the feature of realtime data streaming. The user interface of the portable control unit has been designed in order to allow the usage of the monitoring system by non-technical people. In this sense a The bio-sensors developed during the first two years of the project have been integrated into wearable elements and will be tested on volunteers during the last phase of the project. The BIOTEX project partners are CEA-LETI, Thuasne and Sofileta in France, Smartex, Penelope and University of Pisa in Italy and Dublin City University in Ireland. This work is partly funded by the European Commission. CSEM thanks them for their support and the project partners for their collaboration. [1] BIOTEX stands for Bio-sensing Textile for Health Management (http://www.biotex-eu.com) 87

Wearable Systems to Protect Rescuers and Firefighters during Operations J. Luprano, G. Voirin, G. Dudnik After the first 22 months of activities, the European project ProeTEX [1] confirms the feasibility of an integrated and wearable system for Firefighters, Civil Protection Rescuers and Victims, that will improve safety by monitoring vital signs and environmental signals. The implemented prototypes are being submitted to field trials and the results will provide valuable feedback that will contribute to the future design. In the frame of the European Project PROETEX [1], CSEM in collaboration with 22 partners is developing smart garments with wearable electronics and sensors for helping rescuers during operations. The project aims to improve the security and efficiency of rescuers by integrating portable sensors and communication systems into the garments. The continuous verification of vital and environmental signs allows the prediction of extreme situations regarding the health status and safety of people during their interventions thus becoming a valuable tool in the diagnosis of the risks and eventually saving their lives. Paris (BSSP) under the lead of the partners in charge of this activity, EUCentre and Smartex. The equipment was tested by the firefighters in two typical situations: Obstacle trail reproducing routine (and demanding) gestures of firefighters during their interventions Fire control in training chamber (Figure 2) The main tasks of CSEM are the design of new biosensors [2], the definition of a network topology for the textile and nontextile sensors and the conception of low power portable electronic devices. The portable devices integrate the heterogeneous electronic subsystems that collect, synthesize, and transmit the vital data and information to a remote station in a reliable way. This first version of the prototype collects the information of the different sensors that are distributed in a T-shirt in contact with the body (inner garment) by connecting the analog signals to a portable module located in the outer garment. Information from sensors located in the outer garment are treated locally and transmitted along the jacket (outer garment) by the implemented wired network to the portable module. The latter collects, processes, and synthesizes the information. This module is able to transmit wirelessly point-topoint at a maximal distance of 30 meters to a computer using a standard protocol. The application software allows the processing of the data online, and stores it for further analysis or historical record. The following sensors are currently integrated: Vital body signs: heart and breathing rate, skin temperature, motion and activity. Environment data: external temperature, GPS-based location. Figure 2: BSSP firefighter wearing ProeTEX garment during field trials in St. Denis (Paris 12 December 2007) The next generation of prototypes will be personalized for each type of application and will add the following features: Local treatment of the vital signs for further integration to the sensor network (e.g. combination of heart and respiration signals) and addition of oximetry and sweat measurements. Integration of environmental information: e.g. heat flux and toxic gases. Implementation of a Body Area Network (BAN) to link toxic gas sensors located inside the boots. Addition of mid and long range communication with networking capability. Provision of local alarms suitable to harsh environment. CSEM thanks the European Commission for their support and the project partners for their collaboration. [1] http://www.proetex.org [2] http://www.biotex-eu.com Figure 1: Main blocks of the first system prototype The first prototypes, whose system overview is shown in Figure 1, have proven that the project goals are reachable, without dramatic modification of the end user intervention routine. The first trials were carried out by the Italian Civil Protection (ICP) and the Brigade des sapeurs-pompiers de 88

MEMS Based Miniature Catheter Probe for Ultrasound Imaging R. Gentsch, J. Luprano, P. Pilloud A miniature capacitive micro-machined ultrasound transducer (CMUT) has been developed in the frame of an EURIMUS project. The first target application is a 3mm diameter catheter probe for intra-cardiac imaging. A dedicated 64-channel low noise preamplifier was designed by CSEM to compensate the lower sensitivity and achieve optimum imaging performance. MEMS technology opens exciting perspectives for medical ultrasound imaging transducers: compared with traditional piezoelectric transducers (PZT). The silicon MEMS approach offers potentially lower fabrication costs for volume production, better reproducibility, improved acoustic radiation pattern and wider frequency response. VERMON SA, a French SME company with more than 20 years of experience in development and manufacturing of high performance ultrasonic devices for medical and industrial applications, initiated an EURIMUS project called MEMSORS (Micromachined Electrostatic Membranes for acoustic SensORS). The goal of the project is to develop a miniature 3 mm diameter catheter probe for intra-cardiac imaging with 64 elements. Such a small probe already exists in the lineup of VERMON, but based on PZT technology and thus quite expensive to manufacture. The price of such probes is a sensitive factor since they are single use devices. However, the availability of low-cost CMUT probes would encourage surgeons to use them more often to help them during critical heart operations. The project consortium was formed by partners from France, Germany and Switzerland providing excellent complementarities: VERMON (Tours, France), as project initiator and coordinator, was involved in all project phases, from specification, design and simulations to the integration and evaluation of the prototypes. STMicroelectronics (Tours, France) and MicroFAB (Bremen, Germany) were the two MEMS foundries processing the CMUT wafers which allowed two different processes to be tried out. The University of Tours was involved with two of its laboratories, the Laboratoire Ultrasons Signaux Instrumentation (LUSSI) and the Laboratoire de Microélectronique de Puissance (LMP), both in the design phase and later in the detailed characterization of the CMUT samples. Hybrid SA (Chez-le-Bart, Switzerland) was in charge of the interconnection and packaging issues. The major challenge was to mount a 64-element CMUT measuring 2 mm by 14 mm on a dedicated substrate by providing a connection to four miniature 18-wire ribbon cables on the opposite side. Due to the limited size of the probe all had to fit into a 3 mm diameter catheter. CSEM s task was to design a 64-channel preamplifier module able to compensate the lower CMUT sensitivity compared to PZT probes by providing a 20 db gain over a 30 MHz bandwidth. Very low noise level was one of the key specifications, in order to keep the low level echo signals (sub-millivolt level) as clean as possible. The most demanding requirement was to keep the preamplifier transparent for the ultrasound imaging equipment normally operating with PZT probes. In other words the high voltage pulses sent to the probe for the acoustic emission, presenting amplitudes up to 200 V and rise time in the order of 10 ns, had to pass the amplifier in the opposite direction (from output to input) without damaging the sensitive preamplifier circuit. The overload recovery time had to be kept very short (< 1 μs) in order to minimize the distance to the first visible echo. Another particularity of CMUT devices is that they need a DC voltage biasing (up to 200 V) to get optimum acoustic characteristics, similar to electrostatic microphones. Figure 2: 64--channel preamplifier module and catheter probe (left lower corner: probe tip detail in special transparent finish) During this 3-year project all building blocks could be validated: MEMS processing (CMUT design, processing parameters, membrane stress and coating for optimal acoustic performance, through-wafer vias), probe assembly and interconnection of the 64-element transducer to the cables and electronic module performance. The successful integration of these building blocks prepares the way to an industrial product and the imaging tests done with a final version of the CMUT transducers indeed showed increased acoustic performance over PZT transducers. CSEM thanks the OFFT / CTI for their financial support for the work done by CSEM, the EURIMUS Office for their support to the overall project and all the project partners for their valuable contributions. Pictures: courtesy of Hybrid SA and VERMON SA. Figure 1: 64-element CMUT (2 x 14mm 2 ) on interconnect flex carrier 89

. 90

MICROROBOTICS Christian Bosshard, Philippe Steiert Figure 1: Roadmap Microrobotics The research in Microrobotics at CSEM is based on three Technology Platforms (see Figure 1). A new platform on sensor integration will be started in 2008. Development of fast and precise desk-top industrial robots for microcomponent assembly In March 2007 the CSEM Robotics team won the first prize of the Swiss Technology Award with the concept of the Micro Factory for assembly processes. Based on the PocketDelta the concept was shown as a live demonstration at the Hannover Fair 2007 where it was nominated for the Top Five of the prestigious Hermes Award for excellent technical innovations. In order to extend the technology platform for the MicroFactory to a wider scope of Assembly, the research activities are focused on the three topics (i) modular software tools of object oriented robotics (ii) generic image processing for automation, and (iii) process-driven robotics control. In 2007, the existing platforms were supplemented and the software framework and the control electronics were adapted to current industrial needs. A large part of the research activities were carried out within two EU projects. In the project Hydromel a process for the automatic recognition of the position and orientation of unordered parts has been developed. In the project Nanohand algorithms have been developed for the control of a cameraguided mini robot to handle carbon nanotubes. Handling of fluids and of cells in fluids by combining microfluidics & robotics The Microfluidics & Microhandling team has developed novel methods for the handling of samples and reagents in life sciences. This is achieved through a combination of microfluidics and robotics that allows the sorting and concentration of small particles (cells, functionalized microbeads). A further topic is the fabrication of completely packaged microfluidic systems. Within these activities the integration of sensors and actuators in microfluidic systems played an increasingly important role throughout last year. The infrastructure for the fabrication of prototypes was extended through a micromilling machine, a thermal bonding machine and a lamination apparatus. In addition, the combination or precision robotics and microfluidics has led to the development of a system that allows the automatic selection, immobilization and collection of cells for microinjection. Packaging and interconnect technologies The Optics & Packaging team has developed customerspecific integration solutions from the design phase to the assembly for products in the field of optoelectronics, sensing, MEMS systems and microelectronics. A special focus was put on the development of bonding processes (adhesive fixing, soldering). The packaging activities at CSEM were further extended and Alpnach could establish itself as the center for this domain within CSEM. In terms of technology the existing flip-chip bonding processes were extended. This now allows the simultaneous application of electrical contacts to smart Silicon sensors and leak-tight sealing with respect to liquid and gases. Typical applications are in the area of biodiagnostics with liquids and the hermetic sealing of MEMS devices. Integration of disciplines and industrial relevance The strength of CSEM Microrobotics research program continues to be the integration of the various disciplines including robotics, embedded systems, SW engineering, microfluidics, optics, sensing as well as microsystems integration and packaging. A representative example is the development of a highly compact laser scanner for dermatologic applications carried out for the industrial client Pantec Biosolutions AG which also led to the nomination of the Medtech Award 2007. The successful implementation required the following competences: actuator driver engineering (robotics), digital signal processing and algorithms, mechanics with micrometer precision, optics, sensing, electronics. Research partners CSEM research partners in the field of Microrobotics are ETHZ (Eidgenössische Technische Hochschule Zürich), EPFL (Ecole Polytechnique Fédérale de Lausanne), IMT (Institut de Microtechnique, Université de Neuchâtel), HSLU (Hochschule Luzern), and BFH-TI (Berner Fachhochschule Technik und Informatik, Biel) Research at CSEM Microrobotics Division in Alpnach is supported by the Cantons of Central Switzerland through the Micro Center Central Switzerland (MCCS). 91

NanoHand A System for Automated Nano-Handling An Integrated EU Project A. Steinecker In the integrated EU-project NanoHand of FP6 a nano-manipulation platform will be developed that carries out automated nano-handling of nanotubes or nanowires. Individual handling of nano-components will be addressed inside or outside of a scanning electron microscope (SEM). It is targeted to build prototypes for design and testing of future nano-devices. Together with project partners CSEM realizes a system for nano-handling under a light microscope Nanotubes and -wires show interesting electrical, chemical and mechanical properties. Different application domains benefit from the use of nanowires, as for the following two examples: (i) Nanotubes attached to scanning tips can improve their resolution or add chemical probing sensitivity. (ii) Nanotubes integrated into novel nanoelectronic devices could improve heat dissipation or act as elements in transistors. Handling and positioning of the nanotubes is feasible by complementary approaches: parallel catalytic growth on predefined positions or individual handling by single pick-andplace operations. The latter is focus of the presented work. Individual handling is essential for building prototypes of nanodevices,to achieve a high degree of flexibility and to enable quality control of devices. Nevertheless the task is complicated and lacks dedicated instruments. NanoHand is an integrated European project run under the 6 th Framework Programme [1]. It started in June 2006 and will end in May 2009. Its goal is to provide exploitable systems for nanohandling. integration into an SEM and enable automated In-SEM nanohandling. 10 µm Figure 1: Silicon nanowires (diameter approx. 200 nm) under optical microscope (see Figure 1) Overview camera Mobile Microscope objective Rotation stage The project is grouped into the following sub-projects SP 1: Nano-manipulators and technologies (led by CSEM) SP 2: Applications and industrialization (led by ST) SP 3 and 4: Accompanying measures and management CSEM is leading SP 1: the development and integration of sub-systems for nano-handling. A close collaboration with leading scientific and industrial partners from Europe has been established. The sub-systems for nano-manipulation consist of mobile and fixed piezo robots for precise locomotion and flexible reconfiguration (EPFL), gripping and handling strategies for reliable manipulation of nanotubes and wires (MIC), and vision and control for stable object detection and task automation (OFFIS, CSEM). These components are integrated into a set-up that can be operated in an SEM or under a light microscope. CSEM is developing a microscopic set-up for the automated handling of nanowires outside of the SEM (Figure 1). Nanowires are structures with lateral dimension of up to several 100 µm that can already be observed using light optics. The set-up consists of several piezo robots (cartesian x-y-z stage, mobile robots that can move and rotate on a surface, rotating stage) developed by EPFL. They carry microgrippers provided by MIC to manipulate nanowires. CSEM has integrated the various components under a light microscope (Figure 2). A modular control system has been developed that will enable automated handling based on visual servoing of the robots. In the upcoming project phase the hard- and software elements will be adapted for Figure 2: Nanomanipulation system under a light microscope integrated at CSEM. Sub-systems have been provided by EPFL (mobile nano-robot and rotating stage) and MIC (gripper and samples, not visible in the picture). Project partners: CSEM, EPFL, EMPA, Eurexcel (GB), Futuretech (DE), Klocke Nanotechnik (DE), Technical University Denmark - MIC (DK), Nascatec (DE), OFFIS (DE, Coordinator), ST Microelectronics (IT), VDI VDE-IT (DE).The project is funded by the European Commission in the 6 th Framework Programme (FP6-2005-IST-5, contract number 034274) and by the MCCS. Their support is gratefully acknowledged. Figure 3: Official NanoHand logo xyz stage [1] S. Fatikow, V. Eichhorn, A. Sill, A. Steinecker, C. Meyer, L. Occhipinti, S. Fahlbusch, I. Utke, P. Bøggild, J.-M. Breguet, R. Kaufmann, M. Zadrazil, W. Barth, "NanoHand: micro-nano system for automatic handling of nano-objects", International Symposium on Optomechatronic Technologies (ISOT 2007), Lausanne, Switzerland, 8-10 October 2007 92

Microfactory A Flexible Assembly Platform P. Glocker, R. Wyss, P. Schmid, U. Zbinden, J. Taprogge, M. Honegger, A. Steinecker, G. Gruener, C. Meyer In the future, small components will be assembled on small machines. CSEM has designed small-sized Delta robots with integrated controller hardware and minimized external cabling and footprint. The PocketDelta is an ideal, modular, micro-assembly platform for automatic production in desktop applications. A demonstration Microfactory with four robots shows great potential for saving resources in miniaturized production systems. In the past few years CSEM has invested in the miniaturization of robot systems based on parallel Delta kinematics. The result is the PocketDelta [1], a highly integrated robot platform for micro-assembly applications with up to 4 degrees of freedom (Figure 1). This new tool shows a high potential for future assembly technologies due to the following specifications: High precision: Repeatability < 5 µm Short cycle time: up to 3 cycles per second Small size: 120 x 120 x 240 mm Figure 4: Microfactory assembly line with 4 PocketDeltas presented at the Hannover Fair 2007 Figure 1: The PocketDelta robot In March 2007, CSEM was bestowed with the First Prize of the prestigious Swiss Technology Award [2] for the concept of a miniaturized modular assembly line (Figures 2 and 3). The high position accuracy of the PocketDelta and its short cycle times bring new economical advantages. Note that the MicroFactory does not solve existing assembly problems. Rather, a new technology platform has been launched for future low-cost production systems. Products to be manufactured by this platform should be designed with its performance in mind. One great advantage, though, is the fact that the same system can be used during prototyping and production, reducing development time and risk. Figure 2: CSEM receives the First Prize of the Swiss Technology Award 2007 for its Microfactory concept At the Hanover Fair 2007, CSEM presented a miniature assembly line with four PocketDelta robots (Figures 4 and 5), demonstrating assembly of micro-planetary gears with a housing diameter of 6 mm. CSEM landed within the top-five finalists of the Hanover-Fair associated Hermes Award [3]. Figure 5: Close-up look of the Microfactory assembly line CSEM is developing additional components for the Microfactory, such as part feeders and integrated sensors for force measurement and automatic part location, which will improve the performance of the Microfactory assembly line. [1] S. Perroud, et al., New pocket and desktop Delta robots with integrated controllers, CSEM Scientific and Technical Report 2006, page 80 [2] http://www.swisstechnology-award.ch Figure 3: Microfactory concept for a desktop assembly line with 5 PocketDelta robots [3] http://www.hannovermesse.de/hermesaward_e 93

Isolation and Reversible Immobilization of Single Cells S. F. Graf, P. Schmid, H. F. Knapp An innovative system to meet the need of drug researchers is under development. The novel approach integrates new technologies including microrobotics and microfluidics to achieve a high throughput screening rate which will replace time consuming and costly manual operations used today. To this end, a multipurpose robotic system called CellBot was developed consisting of the high-precision robot µdelta, the fully automated inverse reflected light microscope imic, the tool stage, the fixed working platform and the Carousel for reversible immobilizing of the cells. By using this visual feedback controlled setup an automated isolation and reversible immobilization of single Xenopus laevis oocytes could be demonstrated. Cell-based assays are set to become the preferred choice of screening in drug discovery research, potentially overtaking more traditional approaches that include animal models. New target screening often requires the use of cell assays to detect specific cellular pathways of chemical compounds, therapeutic proteins, sirna agents and other structures of interest. Insight from these assays could help more efficient discovery of effective drugs, thus saving time and costs as well as the need for future secondary screens. The emphasis now for cell-based assay manufacturers is to develop easy-to-use and highly sensitive cell systems as an alternative to current rodent bioassays. High throughput screening (HTS) using cellbased assays will particularly become increasingly needed for both industrial and scientific applications. Introduction of DNA, sirna, or other substances into cells is one important micromanipulation technology applied to develop and optimize various cellular systems, which enables cell systems either to more closely approximate in vivo testing or to become more competent or more specific for various in vitro applications. However, the pharmaceutical industry needs a highthroughput, efficient, and automated system for direct delivery of substances (including compounds, DNA, sirna and mabs) into a large number of cells for HTS use. To address this need, the development of an automated microinjection system is in process. Microinjection is a technique where a glass capillary filled with substances is controlled by a micromanipulator. Cells have to be individually immobilized while the capillary with an apex of 0.5 to 10 µm diameter penetrates the cell and a pressuring device injects the substances. Therefore, as a first step, the isolation of single Xenopus laevis oocytes with a following reversible immobilization is demonstrated. The CellBot [1] setup is used, consisting of a high precision robot µdelta equipped with a glass capillary connected to a peristaltic pump, a fully automated inverted light microscope imic and a fixed working platform with a Petri dish and a Carousel for further cell manipulations (Figure 1). To start the process, the user has to place a suspension of Xenopus laevis oocytes into a Petri dish. Via the user interface the routine can be started: The imic scans the Petri dish (Figure 2) and cells of interest are automatically identified via a pattern matching software based on a set of given parameters If a cell is detected, the glass capillary is automatically guided by vision feedback to pick up the cell and places it into the carousel. The carousel contains specially designed cone structures for immobilizing the cells, with or without negative pressure. By rotating the carousel the cell is moved to the microinjection position, which will be implemented at a later stage. Finally the carousel can be rotated to two additional positions, where the cells can be released into a collection or waste container, respectively. The release of the cells is aided by pressure pulses. The collection container can be removed by the user for further processing. collectio n carousel pipette petri Figure 1: Workspace of the CellBot where the micropipette is about to pick a cell to transfer it to the carousel for immobilization. Figure 2: A special combination of bright and darkfield illumination enables simultaneous detection of several parameters of the Xenopus laevis oocytes, such as shape, size, and coloration, that will identify viable cells. This work was partly funded by the EU (project NMP2-CT- 2006-026622) and the cantons of central Switzerland and the MCCS (Micro Center Central Switzerland). CSEM thanks them for their support. [1] T. Stöckli, et al., High precision robotics for automated cell handling, CSEM Scientific and Technical Report 2006, page 83 94

Bonding of Glass or Silicon Chips with a Self-Sealing Photostructurable Elastomer J. Auerswald, F. Cardot, P. Niedermann, A. Ibzazene, M. Fretz, N. Schmid, H. F. Knapp When it comes to the integration of planar electrodes on glass, quartz, silicon or thermoplastic chips into microfluidic systems, standard bonding methods like diffusion bonding, anodic bonding, thermo-compression bonding etc. do not work. Surfaces carrying electrodes cannot be sealed with a stiff material. The challenge is even bigger when two glass chips with facing electrodes and microfluidic channels in between are required by the application, with an alignment precision down to a few micrometers. Photostructurable polysiloxane could be a solution. The use of photostructurable polysiloxane combines two advantages: Firstly, the good alignment precision of microfluidic channels made by photolithography. Secondly, the reliable permanent bond of silicones to glass, even if the glass chips carry electrodes. Photostructurable polysiloxane is a material known from ISFET and ChemFET sensor packaging. There, typical lateral structure dimensions are several millimeters, sometimes slightly below 1 mm, and are shaped as simple O-rings [1, 2]. However, the use of this material class for microfluidic systems with microfluidic channel networks containing junctions or intersections at channel widths well below 1 mm, and electrodes in the channels has not been demonstrated yet. One of the critical issues is the precise bonding of the cured material to the glass counter chip which also has electrodes on its surface. Figure 2: CAD explosion model (left) and global view of the bonded chip with facing planar top and bottom electrodes, and Luer connectors (right). The alignment precision depends on the used bonding machine and can be as good as 1-2 micrometers with a device bonder. The chips sealed well over the entire gage pressure range up to 28 000 Pa (4 psi), even after the 10th pressure cycle (Figure 3). This is more than enough for typical microfluidic applications. Figure 1: LEFT: Bonded glass chips with facing top and bottom planar electrodes, alignment marks and fluidic access holes. The microfluidic channels are photo-structured into the elastomeric intermediate layer. RIGHT: Bonded chip filled with a colored fluid. 25 μm high microfluidic channels with a width down to 200 μm (and less), with channel junctions, into photostructured polysiloxane on a glass substrate with planar electrodes were structured. It was further achieved to permanently bond the cured material to counter glass chips with planar electrodes. The whole microfluidic system was leak tight, even without an external clamp (Figure 1). The elastomer-based photolithography and the precise bonding process allow for alignment accuracies down to a few micrometers. This high precision combined with good sealing provides a viable alternative to the until now rather unsatisfying sealing results obtained with classic negative tone photoresists such as SU-8, BCB, or polyimide. A possible application is shown in Figure 2. First, microelectrodes are fabricated on a bottom glass wafer. Then, in a second mask process, the photostructurable polysiloxane is deposited and structured. Before dicing, the bottom wafer is protected by a removable resist layer. After removal of the protective resist and surface activation, the chips can be bonded to the diced chips of the top wafer. The top glass chips also have electrodes and pre-drilled fluidic access holes. The bond is permanent, due to the applied surface activation. Fluidic connectors can be glued or tape-bonded above the fluidic access holes. Figure 3: Example of a sealing test. The chips seal well at pump gage pressures of 30 000 Pa (4 psi), even after the 10 th pressure cycle. This is more than good enough for typical microfluidic applications. Potential applications include high-end niche markets for labon-chip systems designed for dielectrophoresis, dielectric spectroscopy, low voltage AC-EOF pumping and other microfluidic applications requiring photolithographic electrodes. This work was partly funded by the EU (project IST-FP6-027540, IntegramPLUS). CSEM thanks them for their support. [1] P. Temple-Boyer, J. Launay, I. Humenyuk, T. Do Conto, A. Martinez, C. Beriet, A. Grisel, Microelectronics Reliability 44 (2004) 443-447. [2] P. Arquint, M. Koudelka-Hep, B.H. van der Schoot, P. van der Val, N. F. de Rooij, Clin. Chem. 40/9 (1994) 1805-1809. 95

Sensor and Connector Integration into Microfluidic Systems using Biocompatible Tape Gaskets J. Auerswald, H. Haquette, H. Keppner, J. Nestler, S. Bigot, M.-C. Beckers, J. Gavillet, G. Delapierre, N. Schmid, S. Berchtold, E. Portuondo-Campa, S. Graf, H. F. Knapp The project goal is to develop a thermoplastic microfluidic cartridge with an integrated glass-based surface plasmon resonance (SPR) sensor for label-free protein detection. Laser-cut tapes were used for sensor and connector integration. First prototypes were fabricated and tested in a protein demonstration assay. The non-specific binding behavior of the tapes with respect to antigen, antibodies, proteins, DNA and RNA was investigated. Laser-cut tape gaskets allow the integration of glass or silicon based sensors into low cost thermoplastic microfluidic systems [1]. The advantages of this bonding approach are: High degree of design flexibility (multi-channel layouts). Good bonding to polar (glass, quartz, silicon, ceramics) and non-polar (thermoplastics) surfaces. Presence of bio-molecules on the sensor surface is possible during the bonding process (no heat, UV or plasma required). Tape bonding also allows the integration of fluidic connectors on the chip and the sealing of channels with cover tape. Figure 1 shows an assembled prototype and laser-cut tapes. angle for aqueous solutions is defined by the prevailing polar or non-polar bond character in the coating. First tests demonstrated the feasibility of the flow stops (Figure 2). For sensitive protein assays, it is important that the proteins are delivered to the sensor and not lost due to non-specific binding at the microfluidic channel walls. The bonding tapes, the cover tapes, the COC and the PE-CVD coatings were tested for non-specific binding of antigens, proteins from serum, biopsy and cell lysate, and antibodies. In addition, the tapes were also tested for non-specific binding of DNA and RNA. Tapes, COC and PE-CVD coatings showed relatively low non-specific binding in these tests (Figure 3). Figure 1: Left: Prototype with glass-based SPR sensor chip, injection molded thermoplastic COC microfluidic channels, and fluidic srew connectors. Right: Laser-cut tapes were used for sensor chip bonding (bottom tapes), channel sealing (top tapes), and connector bonding. The prototypes have successfully been tested in protein demonstration assays. In these assays, human pain markers were detected in specific binding assays on glass chips. The glass chips, already carrying the probe molecules, were tapebonded to thermoplastic COC injection molded microfluidic channels. Further, a gel actuator was successfully tested as an alternative to the external pump, used today. This gel actuator, together with sample, buffer and reference reservoirs, will be integrated into the cartridge in the future. Figure 2: PE-CVD coating of the channel substrates. All channels were coated hydrophilically, except at the junction area, where a hydrophobic flow stop was desired. The coated chip was sealed with an uncoated laser-cut cover tape. Figure 3: Example of a non-specific binding test with antigen and proteins from serum, biopsy and cell lysate. Compared to reference glass and COC slides, the fluorescence signal indicates low nonspecific binding of bio-molecules on a number of tested tapes. The work was supported by the EU (IST-FP6-016768). SPR chips were provided by Zeptosens (a division of Bayer AG). HE-ARC, La Chaux-de-Fonds, Switzerland Technische Universität Chemnitz, Germany Cardiff University, UK Eurogentec SA, Belgium CEA Grenoble, France [1] J. Auerswald, et al., Bonding of SPR Sensors on Glass Chips to Thermoplastic Microfluidic Scaffolds, Proc. Smart Systems Integration Conference, Paris, March 27-28, 2007, 153-160. For controlled actuation and flow behavior with the integrated gel actuators, the cartridge will also possess hydrophobic flow stops at the inlet channel junction area. For this purpose, the COC cartridge will be treated with PE-CVD coatings to define hydrophilic and hydrophobic channel sections. The wetting 96

Pressure Sensing Strip for Rapid Aerodynamic Testing N. Schmid, M. Fretz, S. Bitterli, T. Burch, L. Neumann, J. Auerswald, H. F. Knapp, S. Graf, C. Bosshard, P. Sollberger, F. Zimmermann, Z. Stössel, T. Harvey, J. Zhu, R. Hamza A pressure sensing strip is being developed in order to measure pressure profiles for rapid aerodynamic testing. It combines state of the art pressure sensing technology with integrated micro-fluidic pressure signal guidance in order to produce a non-intrusive pressure distribution measurement device. A patent is pending. Currently low pressure profiles are primarily measured with pressure transducer arrays: A number of tubes lead from a pressure transducer array to corresponding measuring taps on the surface to be measured [1] (Figure 1). Setting up such a system is time consuming and costly and on thin profiles or brittle materials it is not even an option (e.g. sails, glass). Alternatively, non intrusive pressure sensitive paints can be utilized, but there is a lack as far as sensitivity, accuracy and reproducibility is concerned. Pressure sensor Integrated micro-channel Figure 3: Pressure sensor on flexible PCB manufactured at Epigem Courtesy of BMW- Wire-less data transmission can be utilized in order to further increase system flexibility such as mounting the entire device on a rotating blade (e.g. wind turbine). Potential markets can particularly be found in R&D testing environments (e.g. wind tunnels) in following industries: Automotive Aerospace Wind turbines Urban goods Watercrafts HVAC Table 1: Targeted specs Pressure range 6000 Pa Pressure accuracy 30 Pa Pressure resolution 3 Pa Figure 1: Comparison between conventional and CSEM PS strip The pressure sensing strip measures pressure profiles nonintrusively without impeding sensitivity. The device can directly and easily be placed onto the surface to be measured (Figure 2). It combines state of the art pressure sensing technology (piezo-resistive sensors) with integrated microfluidic pressure signal guidance (Figure 3). A film with integrated microchannels guides pressure signals from an arbitrary point on the surface to the sensor, which does does not obstruct the fluid flow at the place of measurement.. Strip thickness (at measuring points) < 0.8 mm Strip length 20 to 500 mm Temperature range 0 to 60 C Measuring speed per sensor 300 Hz This work was supported by the EU, (project IST-FP6-027540, IntegramPLUS) and the MCCS Micro Center Central Switzerland. CSEM thanks them for their support. Tape with integrated micro-channels Pressure sensors Electrical connection Hochschule Luzern Technik & Architektur, Horw Epigem Ltd, Redcar Yole Développement, Lyon [1] Race Car Aerodynamics, Joseph Katz Figure 2: Pressure sensing strip 97

Pressure Sensing Strip Packaging Aspects M. Fretz, N. Schmid, T. Harvey, J. Zhu, A-C. Pliska, C. Bosshard A face-up bonding process for MEMS devices on flexible prints based on silicone rubber was developed. The electrical contacts were provided by gold wire bonds. The process allows the fabrication of flexible pressure sensing strips specially suited for non destructive measurements in R&D environments like wind tunnels. Flexible prints are widely used in (micro-) electronics applications. High resistivity to temperature makes them as easy to handle as rigid FR4 boards. In order to extend the applications of flex prints to microfluidics, it is necessary to develop adequate bonding processes: MEMS devices need to be mounted on flexible platforms. In this case, the flexible platform exhibits air channels with two openings in the top side at each end of the channel. A differential pressure sensor (silicon die) is placed on one end of the channel, this measures the pressure variations at the other end [1]. 1 2 Figure 1: Die attachment process: A square of silicone rubber is dispensed on the flex around the channel opening (1). Then the pressure sensing die is placed above the opening (2). Wire bonds are done after the curing of the silicone. adhesive. If too much is applied, it can be pushed into the opening during die attachment, blocking the channel. Too little adhesive can cause leaks in the silicone ring. In both cases, pressure variations at the other end will not be detected correctly. Then the sensor die was placed on the silicone rubber. The pressing force is rather low and applied only for a short time. A few seconds are enough to provide complete wetting of the sensor die. Higher forces and longer times increase the probability that the opening will be closed by the silicone adhesive. The wire bonds were done with a thermosonic wire bonder after the curing of the silicone rubber. It is the critical part of the packaging: The wire bonding parameters like ultrasonic power, clamping force, and time need to be chosen carefully for this special case. Wire bonding works best if the device is hard and rigid. Here, the sensor die is hard, but it lies on a silicone pillow, allowing the sensor to vibrate during wire bonding. Furthermore, the silicone can give way when the bonding tool pushes down on the sensor pads. Both reduce the energy transfer from the wire bonding machine to bonding interface. Another issue deserves attention: Thermosonic wire bonding requires heat. But the pressure sensor should not be heated above 125 C for a long period of time. These constraints have to be considered when choosing the bonding parameters. On the flex side, the bonding can be optimized by choosing the adequate pad metals and thicknesses. Die attachment and wire bonding are mastered tasks. Nevertheless, optimization is possible: The silver-finished metal pads (see Figure 2) on the flex will be replaced by more suitable metals. The work was supported by the EU, (project IST-FP6-027540, IntegramPLUS). CSEM thanks T. Harvey and J. Zhu from Epigem for the preparation of the flex prints. Epigem Limited, Redcar, UK [1] N. Schmid, et al., Pressure Sensing Strip for Rapid Aerodynamic Testing, in this report, page 97 Figure 2: Pressure sensing silicon die attached to a flex print with silicone rubber. Wire bonds from die to flex pads provide electrical contact. A standard face-up bonding approach of the sensor with gold wire bonds providing electrical contacts was chosen. First, a RTV (room temperature vulcanizing) silicone rubber was dispensed around the opening at one end of the channel (see Figure 1). It is important to dispense the right amount of 98

Flip Chip Bonding on Polymers Die Attach and Leak-Tight Sealing M. Fretz, T. Harvey, J. Auerswald, N. Schmid, A-C. Pliska, C. Bosshard A bonding process for sensing elements on PMMA based platforms or vice versa was developed. A ring of anisotropic conductive adhesive (ACA) forms a cavity between PMMA die and silicon platform. Sealing tests were carried out. This process is suited for dies too small for a micro-gasket approach. As a low cost thermoplastic material, PMMA is specially suited for microfluidic applications and not only for disposable devices. Often a sample to be inspected must be guided to the appropriate sensor element through a fluidic channel or network. Hence, flip chip bonding of the active element on a PMMA platform is a suitable integration approach. Two tasks arise: Flip chip bonding must provide electrical contact, and the sensing area of the chip must be hermetically closed against the ambient air. Both can be achieved by the use of anisotropic conductive adhesive (ACA). In this report, the bonding process of a PMMA die mounted on a silicon platform with a ring of ACA is described. Electrical connection between PMMA and silicon was demonstrated before in [1]. 1 3 Metal pads ACA ring Drilled holes Figure 2: 5 x 5 mm 2 PMMA dies mounted on a dummy silicon platform with anisotropic conductive adhesive. ACA ring 2 Cavity 4 Figure 1: Die attachment process: The gold studs are placed on the pads of a PMMA die (1) and flattened (2). Then the flipped die is mounted on the silicon platform (3), on which a ring of anisotropic conductive adhesive was dispensed. Finally, the cavity is connected to the sealing test set up (4). First, two holes were drilled through the ~5 x 5 x 2 mm 3 PMMA dies. Then, a standard wire bonder was used to place gold studs on the PMMA (see Figure 1). After gold stud bumping, a ring of ACA was dispensed on the silicon platform, followed by the attachment of the flipped PMMA die on the silicon (Figure 2). The attachment step is critical, because ACA requires heat (minimum 125 C) and pressure. But PMMA will warp under load when exposed to temperatures above ~100 C (for more details, see [1] ). Tests were carried out to evaluate the sealing quality of the ACA: Air was pumped through the cavity which was connected to a dead end pressure sensor (for more details, see [2] ).The pressure was increased until it exceeded 1 bar. Then the leakage of the cavity was measured for ten minutes, as well as the leakage of the tubing system alone. The result is plotted in Figure 3. No breakdown of the pressure was observed within twenty minutes. The decrease in pressure is due to the tubing and connectors, as Figure 3 shows. Sealing with ACA can, therefore, be a suitable approach for microfluidic applications which require flip chip bonding of small dies. Figure 3: Leak measurement: The red points (-) depict the pressure evolution in the tubing system only. The blue crosses (x) include both the device with the cavity and the tubing. The work was supported by the EU, (project IST-FP6-027540, IntegramPLUS). CSEM thanks T. Harvey from Epigem for the preparation of the PMMA substrates. Epigem Limited, Redcar, UK [1] M. Fretz, et al., Flip Chip Bonding on Polymers: A Die Attachment Method for Low Tg Materials, CSEM Scientific and Technical Report 2006, page 88 [2] J. Auerswald, et al., Bonding of Glass Sensor Chips with Low- Cost Thermoplastic Microfluidic Scaffolds, CSEM Scientific and Technical Report 2006, page 87 99

Optical / Fluidic Integration of Silicon-Based Hollow Waveguides G. Spinola Durante, J. Auerswald, S. Grossmann, C. Bosshard, M. McNie, A. S. Wilkinson The application of micro/nanotechnology in emerging markets, such as biomedical, healthcare and environmental monitoring requires increasingly complex levels of functional integration across multiple physical domains. The ability to have optical functions within the fluid core offers significant potential for bio-sensing with appropriate detection chemistries. Microfluidic channels are simultaneously formed by bonding glass lids to silicon substrates containing etched waveguides and through-holes to realize fluidic ports. Specific PDMS bonding is being developed and tested with a traditional shear testing method for checking maximum shear strength and pressure drop method for evaluating fluid-leak tightness. The developed approach shows good results in terms of gage pressure of the sealing ring that can withstand more than 140KPa. First trials were made to test the adhesive sealing technology of integrated hollow waveguides (HWG), but the final goal is to prove the innovative possibility to integrate optical waveguides and micro-fluidic channels on wafer scale. The HWG cap wafer is realized by bonding a metallized glass wafer on top of the structured silicon wafer, acting both as a fluid channel enclosure and as a waveguide metallized wall (Figure 1). Optical and Microfluidic functions are being combined in a hollow waveguide platform [1]. Among sealing essential requirements from the application side are: Bio-compatibility in terms of temperature if the sample is already inside the channel (silicon chip) and in terms of materials in case the biological sample is transported throughout fluid motion in the HWG channels HWG bonding profile has to be < 1um to match squareshape optical requirements: zero profile is needed. Sealing ring shear stress resistance Quasi-hermetic or «leak-proof» sealing ring The PDMS on-chip direct dispensing method was selected. Polymer intermediate layer bonding (ILB) proves to be more flexible not only in terms of maximum processing temperature, but also in terms of thickness control of the sealing layer. Fluidic Glass wafer on back Fluidic Port2 Through-holes on Si Figure 2: HWG bonded chips with assembled fluidic connectors The results are encouraging since the graph (Figure 3) indicates a failure of the sealing at gage pressure greater than 140 KPa. This is more than enough for most typical Microfluidic applications. Figure 3: Sealing test measurement of HWG sealed chip ~7mm ~18mm HWG This work was supported by the EU, (project IST-FP6-027540, INTEGRAMplus). CSEM want to thank the EU for its support. Fluidic Port1 Figure 1: HWG chips bonded with a PDMS sealing ring Fluidic Port2 This approach is also promising at wafer level since similar materials can be spin-coated on a glass wafer and UVpatterned. The shear tests have shown that for a tuned PDMS curing process PDMS can yield a maximum shear force of ~2.5 Kg on ~25 mm 2 area, with a bonding temperature below 90 C. The fluid leak-tightness has been tested fixing two standard fluidic connectors to the bonded HWG (Figure 2) and performing a pressurization of the fluid previously loaded in the channel and pipes, through a precision pump. QinetiQ Ltd, Malvern (UK) [1] M. McNie, M. Jenkins, A. S. Wilkinson, A. Turner, G. Spinola Durante, T. Harvey, T. Cox, C. Bosshard, P. Janus, Integration of optical and microfluidic functions in a hollow waveguide platform, Proc. Conference on Smart Systems Integration, Barcelona (E), April 2008 100

Novel Injection-Free Method for Intraepidermal Delivery of Large Molecular Weight Drugs C. Böhler, T. Bragagna, A. Heinrich, S. Summer, S. Gross, G. Boer, S. Grossmann, K. Krasnopolski, Q. Lai, T. Burch, M. E. Busse-Grawitz, D. Fengels Drug patches to deliver substances subcutaneously to replace painful injections are not new, but their application is very limited so far. Many drugs contain large proteins or water-insoluble hormones, which hardly penetrate the skin or do not at all. A novel system has been developed, that makes the skin able to absorb a variety of drugs while it is safe and easy to handle and, in addition, does not cause any pain. Pantec Biosolutions approached CSEM with a vision. The idea was to develop a small handheld system that creates a matrix of superficial micro pores within the epidermis. Tissue damage was to be minimized while damage to blood vessels and nerve cells must be avoided. The micro pores enable a large variety of substances contained in a medical patch to diffuse through the skin barrier and be resorbed by circulation. A consistent, scalable drug diffusion surface can only be achieved by a highly controlled microporation process. developed a first prototype of the scanner, custom tailored to the application and superior in size and cost compared to state of the art solutions. Figure 2: Compact low-cost Laser scanner (left) with projected scanning pattern (right) Figure 1: Transdermal drug delivery - Patches instead of injections during hormone therapy for in-vitro fertilization. The skin layer detection consists of a series of measurements during the ablation process, providing feedback to adopt the Laser energy. CSEM is currently working close with Pantec Biosolutions to implement a first compact system. Two promising methods have been chosen for further investigation. An optical method measures differences in light scattering properties of different skin layers while an acoustic method aims at detecting differences in pressure wave propagation in skin layers with different water content. The system requirements asked for innovative solutions on four technology paths - Laser system development, Laser beam shaping, Laser beam guidance and Skin Layer detection. To shorten time to market and mitigate risks, Pantec decided to go into a CTI project together with CSEM and the IMT. To achieve the required speed and precision, Pantec decided to develop a Laser based microporator. The use of a 2.94 μm Er:YAG Laser aims at an absorption peak of water, enabling ablation of tissue with very constrained undesired thermal tissue damage. With a handheld system in mind, Pantec was able to develop an ultra small, energy efficient Laser system. The beam shaping is an important part of the system and forms the interface between Laser energy and tissue. Pantec conducted clinical studies to learn about the optimum Laser energy distribution in order to create micro pores optimized for drug diffusion. The IMT Neuchatel implemented first prototypes. Diffractive elements made out of silicone showed promising first results. Guiding the laser beam requires compact, high-precision motor control. Within a few seconds, a Laser scanner must place the Laser spot at a few hundred positions on the skin surface and come to a full stop at each position within less than 1 ms at below 10 μm quiescent stability. CSEM Figure 3: Controlled ablation depth, the goal of Skin Layer Detection For the patch development, Pantec Biosolutions has two collaborations, one with a pharmaceuticals company which supplies the active substances, and the second with a reputable patch company which has the task to develop and manufacture the IVF patches. The creativity, clinical expertise and professional drive of Pantec Biosolutions, together with the CSEM multidisciplinary knowhow, have lead to a first working prototype of the device, the so called LEDDT platform (Laser Easy Drug Delivery Technology). This work was funded by CTI. CSEM thanks them for their support. Pantec Biosolutions AG, Ruggell (LI) Institute of Microtechnology, University of Neuchatel (CH) 101

102

TIME AND FREQUENCY Alain Maurissen The new time and frequency division of CSEM is an issue from the transfer July 1 st 2007 of the Observatoire de Neuchâtel activities to the CSEM. Since the invention of the pendulum clock (C. Huygens 1656), time and frequency have been the physical quantities that are measured with the highest precision. It has become a good strategy to translate other physical quantities into time or frequency references (f. i. the meter is now defined as the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second) Recently the appearance of new microelectronic components such as laser diodes and counters/generators working beyond microwave frequencies has generated a worldwide frenetic research activity in the domain. The (r)evolution is such that nowadays the words time and frequency are so closely associated that they can be used instead of each other. Measuring time merely translates into counting cycles of a known frequency (such as the one provided by an atomic clock therefore called frequency standard ). Counting cycles offers the major advantages inherent to the digital domain (in particular its robustness to noise perturbations). The research activities in the new division are perfectly in line with this trend. CSEM strategy is to take full advantage of the ongoing research and development in optical components. The availability of such components will make it possible to break the microwave barrier (GHz) where technology and research were stalling and to quickly move towards fully optical clocks. This means that the available counters will soon operate in the hundreds of terahertz range rather than the tens of gigahertz range. The direct advantages in terms of precision and resolution are evident. Less evident is the fact that one can benefit from these improvements to massively reduce volume, mass and consumption while still keeping acceptable performances. This will approach new domains of applications where the bulky technologies of today are inadequate (portable devices, GSMs, watches ). The all optic compact clock research at the Time and Frequency Division will take full benefit from the available technology and research platforms of the other divisions of CSEM all available under the one roof concept. In 2007, the major efforts of the division were mainly devoted to: Strengthen its position in the development of traditionally compact clocks, mainly for telecom and space applications. Develop a new domain of research around all optical clocks and more precisely ultra-compact optical clocks. Enhance time of flight and lidars technology, more particularly in the PRN domain. The development of the magnetic selection hot Caesium beam clock is now terminated and has been transferred successfully to industry so that in 2008 the production of caesium based atomic frequency standards in Europe will revive (currently only some US companies produce such atomic clocks). The ESA funded Optical Space Caesium Clock research project terminated in 2007 demonstrates that the goal of reaching a 10-12 stability at one second is achievable with a single optical wavelength. This success is paving the way for new optical clock standards to be embarked on navigation and deep space sounding satellites. The follow on activity has already started and aims at demonstrating that such results can be achieved with flight compatible hardware (see Figure 1). Figure 1: Optically pumped Caesium atomic clock for the European Navigation System Galiléo (Prototype in development) The development of the Space Active Hydrogen Maser Engineering Model finished with a full demonstration indicating that performance of ground masers can be approached with space compatible technology and constraints (reduction in dimensions by a factor of approx. 10). The project is now on hold and waiting its restart in the scope of the development of a new generation of embarked space hydrogen masers The latest developments around the lidar demonstrated that PRN modulation of commercially available laser diode leads to eye safe lidars capable of detecting targets at 8 km during daytime. Together with the positive experience accumulated with other lidar types in EU projects, these results gives a boost in the planning of this activity at CSEM. 103

PRN-cw Backscatter Lidar Prototype V. Mitev, R. Matthey, M. Haldimann In the frame of this activity we have realized a prototype of a backscatter lidar, based on the Pseudo-Random Noise modulation of a continuous wave diode laser (PRN-cw). The realized prototype is a compact and robust sensor, capable of detecting solid surfaces and cloud base. Its detection performances are demonstrated for ranges from 600 m till 8000 m. The motivation in the development of PRN-cw lidars is based on the use of cw laser sources in range-resolved remote sensing. Such lidars inherit a number of advantages from the cw laser: high power-efficiency, long life, robustness and compactness, and eye-safety. These advantages make the PRN-cw lidar a potential candidate for space missions in landing, altimetry, surface topography mapping, approaching and docking, collision avoidance, cloud and atmospheric sensing, etc. There are industrial applications that will benefit from the eye-safety of the operation, as well as the compact and durable design traffic control, collision avoidance, etc. The measurements at shorter range are possible with an extremely small number of sequences and respectively short integration times. Figure 2 shows one example of detection of a surface at 739 m, achieved daytime with integration time of 1 millisecond. The test demonstrated that the lidar is capable of detecting surfaces (targets) at ranges till 8 km daytime. The presented activity is supported by ESA and included the realisation of a compact PRN-cw lidar based on standard commercial components, as well as a set of tests for detection of hard target surfaces and cloud-base. Figure 2: Cross-correlation function of backscattered signal from surfaces at 739 m, daytime; Integration time is 1.024 ms. Figure 3 presents an example of cross-correlation function for detection of the backscatter signal from cloud-base. The cloud-base detection is demonstrated for cloud altitudes from 400 m till 3200 m with integration time varying from 0.05 s to 30 s. The measurements were performed also daytime. Figure 1: View of the reported PRN-cw lidar mounted for testing on a pointing table. The dimensions of the lidar main-frame are as follows: 695 mm x 300 mm x 160 mm. The lidar is based on amplitude modulated laser diode with mean power of 400 mw. The laser diode is connected by optical fiber to the transmitting telescope. The transmitter and the receiver telescopes are assembled in a common mechanical frame, also supporting the detector and the electronics blocks for digitalisation and acquisition Figure 1. The PRN sequence is with bin-duration of 50 ns (20 MHz modulation frequency). The received backscatter signal is detected by an APD, amplified by a variable-gain amplifier and digitalized. The digitalisation is performed with 80 MHz sampling rate, i.e., with 4 times oversampling and follow-on decimation of 4 times. In this way the sampling frequency of 80 MHz relaxes the requirements for the low-pass anti-alias filter without degradation of the range resolution. The generation of the PRN code, the signal accumulation and decimation, are performed in a FPGA-based system. The operation control of the lidar is carried by a PC connected via USB interface to the FPGA. The calculation of the crosscorrelation function is also performed in this PC, by a code based on FFT procedure. Figure 3: Example of cross-correlation function of cloud-base backscattered signal. Integration time is 10s, daytime. Numerical tools for performance simulation of the PRN-cw lidar with analog detection have been realized. The comparison with the test measurements shows the adequacy of the numerical model, allowing the simulation and assessment of future application scenarios for advanced PRN-cw lidars. 104

Space Hydrogen Active Maser S. Zivanov, C. Weber One of the two frequency standards that will be part of the Atomic Clock Ensemble in Space (ACES) payload to be flown on the International Space Station (ISS) is an active Space Hydrogen Maser (SHM) mandatory for its ultimate frequency stability performance in the mid-term range (3 s τ 3000 s). The Engineering Model developed in CSEM reaches the weight of the 35 kg SHM, the lightest ever built active maser. The SHM instrument is divided into two principal functional packages, the Physics Package (Figure 1), that provides the actual atomic oscillator, and the Electronics Package (Figure 2), that provides the atomic signal processing circuits, parameter control functions, telemetry and telecommand. The Physics Package is made of the microwave cavity and magnetic shield assembly, the electronics unit and several integrated peripherals like the hydrogen distribution assembly and the ion pumps. developed at CSEM reach a high atomic signal and operating quality factor. The hydrogen atomic beam and storage bulb are maintained under high vacuum with an ensemble of getters and ion pumps. The getter ensemble allows a vacuum autonomy of 10 days without electrical power and an instrument life time of more than 5 years. The thermal regulation is based on three pairs of concentric heaters regulating the microwave cavity temperature with a stability of 1 mk. The heat is evacuated by conductance through the mechanical structure only. An Automatic Cavity System (ACT), based on a sampled interrogation scheme, prevents SHM drifts due to the cavity pulling. The magnetic shielding is enhanced with an active compensation control loop. A step further in the direction of the size reduction is the removal of the external vacuum enclosure which provides the so called thermal vacuum. This vacuum will be provided instead and directly by the space vacuum, given that the SHM is operating in the space environment. The Electronics Package is composed of an RF unit in charge of frequency locking the local quartz oscillator on the hydrogen clock transition frequency as well as frequency locking the microwave cavity using the ACT, of providing the proper microwave frequency to the hydrogen dissociation power amplifier, and finally of delivering a stable 100 MHz signal to the ACES payload. The Control Unit and the Power Supply Unit provide and/or control the necessary powers for an optimal operation of SHM. Finally, the Control Unit interfaces to the ACES payload in terms of telecommands and telemetries. Figure 1: The photo of the Engineering Model and cross-section schematics view of SHM instrument: 1: Microwave cavity and shields assembly; 2: Hydrogen-vacuum assembly; 3: Ions pumps; 4: Low noise RF amplifier 5: External fixation structure; 6: Hydrogen distribution assembly. In order to fulfill miniaturization, the sapphire resonator acts as a "dielectric load" reducing the size of the microwave cavity and serving at the same time as the storage container for the atomic hydrogen. The microwave cavity is made of titanium and tuned mechanically, thermally and electrically at the hydrogen hyperfine frequency. The atomic storage bulb is a sapphire cylinder of 1.7 liters bonded to the titanium cavity covers and Teflon coated. This volume, comparable to a full size maser design, and the Teflon coating technology Figure 2: The functional block diagram of the SHM Electronics Package The main objective of the current development is to perform an end-to-end performance demonstration, to be used as a stepping stone for pursuing the development of the SHM and aiming at the delivery of the SHM Proto Flight Model (PFM). 105

106

COMLAB Alex Dommann CSEM develops, produces and integrates custom or standard innovative microsystems (sensors, actuators and their integration into micro-systems) by exploiting its advanced technologies to provide new integrated solutions to industrial and institutional customers. Targeted markets and applications include automotive, telecommunications, security, health care, biotechnology and environment markets in which system miniaturization and integration is a must. In close collaboration with the regional industry, research organizations, universities and the political authorities, the market for small volume production has been selected. Since the region between Lausanne and Neuchatel is already home to a substantial, successful MEMS cluster and CSEM has a rich portfolio of MEMS solutions to offer, it was obvious to increase the Comlab activities. The global objective of Comlab is to supply a technology support for the R&D and production projects of CSEM, IMT (University of Neuchatel) and other publically funded R&D laboratories in the field of micro- and nanosystems like the CMI at the EPFL in Lausanne. CSEM concentrates its cleanroom activities towards reliable and qualified processes rather than developing absolute unique processes. Thus, CSEM is complementary to the CMI and IMT environment and also plays a role as an industrial company. Within the Subprogram Foundry Services, the Comlab organized the processing of the structures within the different programs of the divisions. Applications were minimal invasive medical instruments, MEMS for space, watch parts, fluidic channels and many other structures needed for evaluating the possibilities of the technology. The laboratory also fabricates prototypes and demonstrators that are used in advanced R&D programs of the industry. The flexibility of Comlab for the fabrication of small quantities of prototypes has proven to be attractive to industry for their R&D programs. To improve the power and the reliability of the foundry services, a quality manager with industrial experiences was hired. Within the Subprogram Process Development the Comlab developed new processes needed in research programmes as well as for the small volume production. The Subprogram Quality Control is focusing on a key issue for the industrialization of MEMS. Quality control, however, needs attention at every development step. Reliability, testability as well as aging are key words which are essential to the industrialization of MEMS. CSEM, in collaboration with IMT (group of Prof. N.F. de Rooij) has moved one step further to industrialization by combining the service of the Micro- and Nanoscopy (SMN, Dr. Massoud Dadras from IMT) with an additional X-ray service headed by Dr. Antonia Neels to a true quality management lab. Quality control is one way to differentiate CSEM from the Universities. 249 samples were measured and analyzed by the new X-ray service during the year 2007 and 321 structure analyses were carried out. The X-ray service was engaged in different applications for European Projects and projects on long term stability/aging of MEMS by HR-XRD. The goal of the X-ray Diffraction Laboratory for MEMS is to develop a test procedure for MEMS devices that: Produce data that will help the system designers understanding of end-of-life characteristics Can be adapted to the failure modes of MEMS devices. Can help to find correlation of the defect analysis with mechanical properties for Si based micro systems. Life time estimations of specific Si based devices under different environmental conditions. To develop a quality control tool based on X-ray defect analysis. HRXRD measures the strain of a crystal with high resolution. This non destructive method obtains quantitative data on the strain present in a sample. CSEM uses HRXRD to assess the strain in DRIE etched processed silicon beams. Strain deforms the silicon beam leading to an appreciable sample curvature which is detected via the broadening of the X-ray peak in a rocking-curve measurement. In the future the collaboration between IMT and EPFL will be enforced. 107

Quality Control A. Dommann, A. Ibzazene, A. Neel Quality control is one way to differentiate CSEM from the Universities. Substantial efforts have been undertaken to bring this capability to an internally recognized performance level. 249 samples were measured and analyzed by the new X-ray service during the year 2007. The X-ray service was engaged in: A CTI Project with OC Oerlikon at Balzers Different applications for European projects Projects on long term stability / aging of MEMs by HR- XRD High resolution X-ray diffraction (HRXRD) is routinely used for the investigation of composition, strain, orientation and overall quality of thin films and bulk crystalline structures. A high-resolution X-ray diffractometer measures the strain of a crystal. This is an accurate, non destructive method applied in the field of MEMS to obtain quantified results on the crystalline disorder. Aging of micromachined silicon actuators often goes along with a change of the strain profile. HRXRD is therefore an optimal analysis tool for aging investigation on MEMS. For the X-ray measurements a Panalytical MPD high-resolution diffractometer was used. Typically, a strong argument to use monocrystalline material and, especially, silicon is its potential resistance against aging. However, quantified results of this fact are rarely published [1, 2]. Schweitz [3] has described methods to characterize mechanically the properties of thin films. Some of them may be used for aging studies. Comparison between theoretical fracture values and real measurements show more than a factor of 10 differences between differently prepared structures. The reasons are manifold, however they are related to the surface roughness as well as to the defect concentration of the etched surfaces due to the ion bombardment [4]. Aging of a MEMS results in a change of the crystal strain profile. Therefore, aging of a crystal can be documented by this method as a change of the strain profile) [5]. In addition, the X-ray standing wave method (XSW) and reciprocal space mapping (RSM) [6] permit to characterize the amount of crystalline defects introduced by cycling and by manufacturing of MEMS devices. The surface roughness can be measured by AFM methods. The goal of the X-ray Diffraction Laboratory for MEMS is to develop a test procedure for MEMS devices that: Produce data that will help the system designers understanding of end-of-life characteristics Can be adapted to the failure modes of MEMS devices mirror X X-ray source primary beam monochromator Figure 1: HRXRD measuring setup sample diffracted beam analyzer (optional) φ detector ω χ [1] S. Arney, Designing for MEMS Reliability, MRS Bulletin, April 2001, 296 [2] R. Shea Herbert, Reliability of MEMS for space applications, Proc. SPIE Int. Soc. Opt. Eng. 6111, 61110A (2006) [3] J.-Å Schweitz, Mechanical Characterization of Thin Films by Micromechanical Techniques, MRS Bulletin, XVII, 7 (1992), 34-45 [4] E. Mazza and J. Dual, Mechanical behavior of a µm-sized single crystal silicon structure with sharp notches. J. Mechanics and Physics of Solids 47 (1999), 1795-1821 [5] T. Vreeland Jr, A. Dommann, C.-J. Tsai and M.-A Nicolet, X-ray Diffraction Determination of Stresses in Thin Films, Res. Soc. Symp. Proc., Vol. 130 (1989), 3-12 [6] A. Dommann, A. Enzler, N. Onda, Advanced X-ray analysis Techniques to Investigate Aging of Micromachined Silicon Actuators for space Application, Microelectronics Reliability, 43 (2003), 1099-1103 2θ HRXRD measures the strain of a crystal with high resolution (Figure 1). This non destructive method obtains quantitative data on the strain present in a sample. CSEM uses HRXRD to assess the strain in DRIE etched processed silicon beams. Strain deforms the silicon beam leading to an appreciable sample curvature which is detected via the broadening of the X-ray peak in a rocking-curve measurement. 108

ANNEXES Publications [1] L. Aeschimann, F. Goericke, J. Polesel-Maris, A. Meister, T. Akiyama, B. Chui, U. Staufer, R. Pugin, H. Heinzelmann, N.F. de Rooij, W.P. King, P. Vettiger "Piezoresistive scanning probe arrays for operation in liquids" Journal of Physics: Conference Series, 61 (2007) 6 [2] T. Akiyama, L. Aeschimann, L. Chantada, N.F. de Rooij, H. Heinzelmann, H.-P. Herzig, O. Manzardo, A. Meister, J. Polesel-Maris, R. Pugin, U. Staufer, P. Vettiger "Concept and Demonstration of Individual Probe Actuation in Two-Dimensional Parallel Atomic Force Microscope System" Japanese Journal of Applied Physics, 46 (2007) 6458 [3] N. Blondiaux, S. Zürcher, M. Liley, N. D. Spencer "Fabrication of Multiscale Surface-Chemical Gradients by Means of Photocatalytic Lithography" Langmuir, 23 (2007) 3489 [4] B. Büttgen, M.-A. El Mechat, F. Lustenberger, P. Seitz "Pseudo-Noise Optical Modulation for Real-Time 3D-Imaging with Minimum Interference, " IEEE Transactions on Circuits and Systems, 54 (October 2007) 2109 [5] B.W. Chui, L. Aeschimann, T. Akiyama, U. Staufer, N.F. de Rooij, J. Lee, F. Goericke, W.P. King, P. Vettiger "Advanced temperature compensation for piezoresistive sensors based on crystallographic orientation" Review of Scientific Instruments, 78 (2007) 43706 [6] A. Dommann, G. Kotrotsios, A. Neels "MEMS Reliability and Testing" MST News, 3/07 (2007) 33 [7] P. Drobinski, V. Mitev, et al. "Föhn in the Rhine Valley during MAP: A review of its multiscale dynamics in complex valley geometry" Quarterly Journal of the Royal Meteorological Society, 133-B (2007) 897 [8] M. Fretz, T. Harvey, A-C. Pliska, C. Bosshard "Flip-Chip Bonding on Polymers: A Die Attachment Method for Low Tg Materials" MST News, 4 (2007) 27 [9] V. Friedli, Ch. Santschi, J. Michler, P. Hoffmann, I. Utke "Mass sensor for in situ monitoring of focused ion and electron beam"applied Physics Letter, 90 (2007) [10] P. Glocker "Mikromontage mit Innovationspotential" A&D Select Robotik&Automation, 9 (2007) 36 [11] H.F. Knapp "Precise Handling of Liquids and Cells" MST News, 5 (2007) 37 [12] C. Kottler, F. Pfeiffer, O. Bunk, C. Grünzweig, J. Bruder, R. Kaufmann, L. Tlustos, H. Walt, I. Briod, T. Weitkamp, C. David "Phase contrast X-ray imaging of large samples using an incoherent laboratory source" Phys. Stat. sol. (a), 204 (2007) 2428 [13] Q. Lai, T. Burch, S. Grossmann, A. Stump, K. Krasnopolski, M. Busse-Grawitz, D. Fengels, C. Böhler, T. Bragagna, A. Heinrich, S. Gross, S. Summer, B. Nussbaumer, G. Boer "Medizintechnik Spielgrund für Innovation" STZ/SWISS ENGINEERING, 10 (2007) 31 [14] G. Martucci, V. Mitev, R. Matthey, H. Richner "Comparison between Backscatter Lidar and Radiosonde Measurements of the Diurnal and Nocturnal Stratification in the Lower Troposphere" Journal of Atmospheric and Oceanic Technology, 24 (2007) 1231 [15] E. Onillon "Europe s New Weather Satellite" dspace News, (February 2007) 14 [16] C. Piguet "Consommation statique: modèles, évolutions et perspectives " Techniques et Sciences Informatiques, RSTI série TSI, 26, n 5/07 (May 2007) 623 [17] C. Piguet "Low-Power Design of Systems on Chip " Digital Design and Fabrication, edited by Vojin Oklobdzija, SPI Publishers, (2007) 39464 109

[18] A.-C. Pliska, C. Bosshard "Adhesive bonding of passive optical components" Micro and Opto-Electronic Materials and Structures - Physics, Mechanics, Design, Reliability and Packaging, 1 (2007) 487 [19] J. Polesel-Maris, L. Aeschimann, A. Meister, R. Ischer, E. Bernard, T. Akiyama, M. Giazzon, P. Niedermann, U. Staufer, R. Pugin, N.F. de Rooij, P. Vettiger, H. Heinzelmann "Piezoresistive cantilever array for life sciences applications" Journal of Physics: Conference Series, 61 (2007) 955 [20] J. Ramm, M. Ante, H. Brändle, A. Neels, A. Dommann, M. Döbeli "Thermal stability of thin film corundum-type solid solutions of (Al1-xCrx)2O3 synthesized under low temperature non equilibrium conditions" Engineering Materials, 9 (2007) 604-608 [21] M. Roerdink, J. Pragt, I. Korczagin, M.A. Hempenius, T. Stöckli, Y. Keles, H.F. Knapp, C. Hinderling, G.J. Vancso "Templated Growth of Carbon Nanotubes with Controlled Diameters Using Organic-Organometallic Block Copolymers with Tailored Block Lengths" Journal of Nanoscience and Nanotechnology, 7 (2007) 1052 [23] A. S. Roy, C. C. Enz "Analytical Modeling of Large-Signal Cyclo- Stationary Low-Frequency Noise With Arbitrary Periodic Input" IEEE Trans. Electron Devices, 54, 2537 [24] A. S. Roy, C. C. Enz, J.-M. Sallese "Modeling in Lateral Nonuniform MOSFET" IEEE Trans. Electron Devices, 54, 1994 [25] N. Virag, R. Sutton, R. Vetter, T. Markowitz, M. Erickson "Prediction of vasovagal syncope from heart rate and blood pressure trend and variability: Experience in 1,155 patients" Heart Rhythm, 4 (November 2007) 1377 [26] C. Voigt, B. Kärcher, H. Schlager, C. Schiller, M. Krämer, M. de Reus, H. Vössing, S. Borrmann, V. Mitev "In-situ observations and modeling of small nitric acid-containing ice crystals" Atmospheric Chemistry and Physics, 7 (2007) 3373 [27] U. Yodprasit, C. C. Enz, P. Gimmel "Common-mode Oscillation in Capacitive Coupled Differential Colpitts Oscillators" Electronics Letters, 43, Nr. 21 (October 2007) 1127 [22] A. S. Roy, C. C. Enz, J.-M. Sallese "Source Drain Partitioning in MOSFET" IEEE Trans. Electron Devices, 54, Nr. 6 (June 2007) 1384 Proceedings [1] J. Auerswald, P. Niedermann, F. Dias, H. Keppner, J. Nestler, K. Hiller, T. Gessner, H.F. Knapp "Bonding of SPR Sensors on Glass Chips to Thermoplastic Microfluidic Scaffolds" Smart Systems Integration Conference, T. Gessner, Paris, FR, March 07, 153 [2] J. Ayadi, H. Zhan, J. R. Farserotu "Maximum Likelihood Time of Arrival Estimation for UWB Signals" IEEE International Symposium on Signal Processing and its Applications, IEEE ISSPA, Sharjah, AE, February 2007 [3] J. Ayadi, H. Zhan, J. R. Farserotu "Ranging Algorithms for UWB Communication Systems" International Conference: Sciences of Electronic, Technologies of Information and Telecommunication, SETIT, Hammamet, TN, March 2007 [4] M.-A. El Mechat, B. Büttgen "Realization of Multi-3D-TOF Camera Environments Based on Coded-Binary Sequences Modulation" Optical 3-D Measurement techniques VIII, Grün, Kahmen, Zurich, CH, July 2007, 26 [5] M. El-Khoury, J. Solà I Caros, V. Neuman, J. Krauss "Portable SpO2 Monitor: A Fast Response Approach" IEEE Portable 2007, IEEE, Orlando, US, March 2007 110

[6] M. El-Khoury "Body Sensor Networks and Portable Monitoring Systems" IEEE Portable 2007, IEEE, Orlando, US, March 2007 [7] J. R. Farserotu "Short range wireless connectivity for health and wellness-draft V0.1" ETSI EP ehealth, ETSI, Sophia Antipolis, FR, December 2007 [8] M. Fretz "Simulation of Hygro Swelling Induced Stresses in Flip Chip Interconnects in a Stress-Sensitive Chipon-Board Configuration" Comsol Conference 2007, M. Fretz, Grenoble, FR, October 2007, CD proceeding [9] J. Gerrtis, J. R. Farserotu "FM-UWB: A low Complexity Constant Envelope LDR UWB Communication System" IEEE802.15, Wireless Personnal Area Networks, Study group BAN, WPAN, July 2007 [10] E. Grenet "Embedded high dynamic range vision system for real-time driving assistance" Sensorik für Fahrerassistenzsysteme, Heilbronn, DE, September 2007 [11] C.A. Griffiths, S. Bigot, E. Brousseau, M. Heckele, J. Nestler, J. Auerswald "Polymer inserts tooling for prototyping of micro fluidic components in micro injection moulding" 4M 2007 Conference on Multi-Material Micro Manufacture, S. Dimov, W. Menz, Y. Toshev, Borovets, BG, October 2007, 113 [12] T. Heldal, T. Volden, J. Auerswald, H.F. Knapp "Embedded Low-Voltage Micropump Based Using Electroosmosis of the Second Kind" NSTI Nanotech 2007, 10th Annual Nanotechnology Conference and Trade Show, The Nano Science and Technology Institute (NSTI), USA, Santa Clara, US, May 2007, Vol. 3, 268 [13] S. Henein, M. Stampanoni, U. Frommherz, M. Riina "The Nanoconverter: a novel flexure-based mechanism to convert microns into nanometers" 7th International Conference of the European Society for Precision Engineering & Nanotechnology, EUSPEN, Bremen, DE, May 2007 [14] K. Hiller, T. Gessner, J. Nestler, J. Gavillet, S. Getin, E. Quesnel, S. Martin, G. Dellapierre, J. Soechtig, G. Voirin, L. Buergi, J. "Integration Aspects of a Polymer Based SPR Biosensor with Active Microoptical and Microfluidic Elements" Smart Systems Integration Conference, T. Gessner, Paris, FR, March 07, 295 [15] H-B. Li, J. Shwoerer, Y.M. Yoon, J. R. Farserotu "IEEE802.15.6 Regulation Subcommittee Report, IEEE802.15, Wireless Personnal Area Networks" IEEE802.15, Wireless Personnal Area Networks, IEEE P802.15-07-0939-00-OBAN, WPAN, Atlanta, US, November 2007 [16] G. Martucci, R. Matthey, V. Mitev, H. Richner "Lidar determination of the frequency of variations of the boundary-layer top" IGARSS 2007, Barcelona, SP, 23-27 July 2007, Paper 1107 [17] V. Mitev, M. Sato, T. Ebizuzaki, Y. Takizawa, Y. Kawasaki, R. Matthey "Atmospheric Monitoring System of JEM-EUSO Mission" 30th International Cosmic Ray Conference, Merida, MX, July 3-11, 2007, Paper 0846 [18] V. Mitev, R. Matthey, G. Martucci, V. Yushkov, N. Sitnikov, A. Lukyanov, E. Lapshova, A. Ulanovsky, F. Ravegnani "Evidences for vertical transport connected to cirrus clouds formation in the tropical UTLS, observed with stratospheric aircraft 'Geophysica' " European Geosciences Union (EGU) General assembly, Vienna, AU, 15-20 April 2007, AS1.09-1TH1P-0022 [19] J. Nestler, A. Morschhauser, K. Hiller, J. Auerswald, H.F. Knapp, T. Otto, T. Gessner "Fully Integrated Polymer Based Microfluidic Pumps and Valves in Lab-on-Chip Systems for Point-of- Care Use" Smart Systems Integration Conference, T. Gessner, Paris, FR, March 07, 565 [20] J. Nestler, A. Morschhauser, K. Hiller, S. Bigot, J. Auerswald, J. Gavillet, T. Otto, T. Gessner "Electrochemical microfluidic pumps based on super absorbing polymers" 11th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS), J.-L. Viovy, P. Tabeling, S. Descroix, L. Malaquin, Paris, FR, October 2007, 1504 111

[21] E. Onillon, P. Theurillat, A. O Hare, P. Spanoudakis, P. Schwab "Mechanical Slit Mask Mechanism Breadboard for the MOSFIRE instrument of the KECK Telescope Spectrometer" IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM 2007, Zurich, CH, September 2007 [22] J. Osmond, G. Isella, D. Chrastina, R. Kaufmann, H. von Känel "Ge/Si (100) heterojunction photodiodes fabricated from material grown by low energy plasma enhanced chemical vapor deposition" 5th International Conference on Silicon Epitaxy and Heterostructures (ICSI-5), to be published in Thin Solid Films, Elesevier, Marseille, FR, May 2007 [23] A. Perret, K.D. Lang, G. Poupon "Euripides White Book" [24] C. Pickering, M. McNie, C. Reeves, T. Harvey, T. Ryan, C. Bosshard, H.F. Knapp, G. Schröpfer, F. von Germar, T. Bauer, P. Janus, P. Gabriec, C. Moldovan, B. Firtat, A. Richardson "Multi-domain and multi-technology integration for next generation MNT products" Smart Systems Integration Conference, Paris, FR, March 07, 73 [25] C. Piguet "Histoires des microprocesseurs horlogers 2/3" Bulletin de la Société Suisse de Chronométrie, 54 (May 2007) 31 [26] C. Piguet "Histoires des microprocesseurs horlogers 3/3" Bulletin de la Société Suisse de Chronométrie, 55 (September 2007) 33 [27] A.-C. Pliska, R. Bauknecht, R. Krähenbühl, A. Peterhans, A. Stump, S. Aiterrami, C. Bosshard, J. Kunde "Compact 90 multi-fiber releasable connection" Smart Systems Integration Conference, T. Gessner, Paris, FR, March 07, 223 [28] J. Rousselot, A. El-Hoiydi, J-D. Decotignie "On the Problem of Near-Far Interference with Impulse Ultra Wide Band radios" European Ultra Wide Band Radio Technology Workshop, UWB 2007, Grenoble, FR, May 2007 [29] J. Rousselot, A. El-Hoiydi, J-D. Decotignie "Performance evaluation of the IEEE 802.15.4A UWB physical layer for Body Area Networks" 12th IEEE Symposium on Computers and Communications, ICC 2007, Aveiro, PT, July 2007, 969 [30] P.-F. Rüedi, E. Grenet, F. Lustenberger "Battery powered high dynamic range vision system" ISCAS, New Orleans, US, May 2007, 1200 [31] P.-F. Rüedi "High dynamic range vision sensor for embedded applications" Image sensor analog and digital on-chip processing, Toulouse, FR, November 2007 [32] P. Seitz, S. Beer, Y. Delley "Smart pixel array for the simultaneous detection of phase and amplitude envelope, enabling real-time nanometer-precision OCT" Frontiers of Electronic Imaging, P. Seitz, Munich, DE, June 2007, 76 [33] P. Seitz "Optical Biochips" 4th Optoelectronic and Photonic Winter School on Biophotonics, L. Pavesi, Trento, IT, March 2007, 14 [34] P. Seitz "Photon-Noise Limited Distance Resolution of Optical Metrology Methods" SPIE Conference on Optical Metrology, W. Osten, Munich, DE, June 2007, 66160D [35] P. Seitz "The history of optical time-of-flight techniques for 3D imaging " Frontiers of Electronic Imaging, P. Seitz, Munich, DE, June 2007, 62 [36] P. Seitz "Tiens, vous voulez faire une carrière scientifique" Atelier du Laboratoire Européen Associé en Microtechnique, S. Grassi, Arc-et-Senans, FR, September 2007, 50 [37] J. Solà I Caros, O. Chételat, J. Krauss "On the reliability of pulse oximetry at the sternum" 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE EMBC 2007, Lyon, FR, August 2007 112

[38] J. Solà I Caros, O. Chételat "Combination of multiple light paths in pulse oximetry: the finger ring example" 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE EMBC 2007, Lyon, FR, August 2007 [39] J. Solà I Caros, O. Chételat "Opto-electric cardiovascular monitoring" SSBE 2007, CSEM, Neuchatel, CH, August 2007 [40] P. Spanoudakis, P. Schwab, S. Droz, J-P. Jeanneret, S. Henein "Flexure-based micro-gripper for robotic applications" 7th International Conference of the European Society for Precision Engineering & Nanotechnology, EUSPEN, Bremen, DE, May 2007 [41] G. Voirin, G. Dudnik, J. Luprano "Advanced e-textiles for firefighter and civilian victims" 3rd Global Plastic Electronics Conference & Showcase, Plastic Electronics Foundation, Frankfurt, DE, October 2007 [42] D. Wehrle, D. Feriencik, A. Hutter, L. Garcia, P. Pelissou, F.J. Lopez Hernandez, K. Pribil, I. Hernandez Velasco, P. Plancke, R. Magness "The Wireless Intra-spacecraft Data Handling Demonstrator Development for the European Space Agency" DAta Systems In Aerospace, DASIA 2007, Naples, IT, May-June 2007 [44] H. Zhan, J. Ayadi, J. R. Farserotu, J.-Y. Le Boudec "A novel maximum likelihood estimation of superimposed exponential signals in noise and ultrawideband application" 19th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, IEEE PIMRC 2007, Athens, GR, September 2007 [45] H. Zhan, J. Ayadi, J. R. Farserotu, J.-Y. Le Boudec "High Resolution Impulse Radio Ultrawideband Ranging" IEEE International Conference on Ultra-Wideband, ICUWB2007, Singapore, SG, September 2007 [46] H. Zhan, J. Ayadi, J. R. Farserotu, J.-Y. Le Boudec "Ultra Wideband Ranging under Multi-User Environments Based on Hidden Markov Model" 10th International Symposium on Wireless Personal Multimedia Communications, WPMC 07, Jaipur, IN, December 2007 [47] H. Zhan, J. Ayadi, J. R. Farserotu, J.-Y. Le Boudec "Impulse Radio Ultra-Wideband Ranging under Mulit-User Environments Based on Hidden Markov Model" 10th International Symposium on Wireless Personal Multimedia Communications, WPMC 07, Jaipur, IN, December 2007 [43] Q. Xu, J. R. Farserotu, J.-F. Zürcher, A. Skrivervik "Broadband small array antenna for high altitude platforms applications" 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, IEEE PIMRC 2007, Athens, GR, September 2007 Conferences and Workshops J. Auerswald, P. Niedermann, F. Dias, H. Keppner, J. Nestler, K. Hiller, T. Gessner, H.F. Knapp "Smart Systems Integration Conference" Assembly and Interconnect Technologies, Paris, FR, March 2007 J. Ayadi "International Conference: Sciences of Electronic, Technologies of Information and Telecommunication" SETIT, Hammamet, TN, March 2007 J. Ayadi "IEEE International Symposium on Signal Processing and its Applications" IEEE ISSPA, Sharjah, AE, February 2007 113

A. Bonfiglio, N. Carbonaro, C. Chuzel, D. Curone, G. Dudnik, F. Germagnoli, D. Hatherall, J.-M. Koller, T. Lanier, G. Loriga, J. Luprano, G. Magenes., R. Paradiso, A. Tognetti, G. Voirin, R. Waite "Managing catastrophic events by wearable mobile systems" MobileResponse 20007, International Workshop on Mobile Information, Sankt Augustin, DE, February 2007 N. Blondiaux, S. Zürcher, S. Morgenthaler, R. Pugin, N.D. Spencer, M. Liley "Fabrication of multiscale, surface chemical and surface structure" SAOG-GSSI, 23rd annual meeting, Fribourg, Switzerland, January 2007 C. C. Enz, J. Baborowski, J. Chabloz, M. Kucera, C. Muller, D. Ruffieux, N. Scolari "Ultra Low-Power MEMS-based Radio for Wireless Sensor Networks" European Conference on Circuit Theory and Design (ECCTD), Sevilla, ES, August 2007 J. Chabloz, D. Ruffieux, A. Vouilloz, P. Tortori, F. Pengg, C. Muller, C. C. Enz "Frequency Synthesis for a Low-Power 2.4 GHz Receiver Using a BAW Oscillator and a Relaxation Oscillator" European Solid-State Circuit Conference (ESSCIRC), Munich, DE, September 2007 O. Chételat "Continuous multiparameter health monitoring" Colloque Médecine Aerospatiale, Genève, CH, June 2007 A. Dommann "Acta Materialia Gold Medal Workshop; Commercialization of Nanotechnology" 2007 E-MRS Fall Meeting, Wasaw, PL, September 2007 A. Dommann "Aging measurements on microstructures" HRXRD Workshop, CSEM, Neuchatel, CH, August 2007 A. Dommann "Coating technologies for the watch industry" CCMX-Conference, Lausanne, CH, June 2007 A. Dommann "Coatings and MEMS for Lifesciences" Lohmann & Rauscher Science Day, Bonn, DE, February 2007 A. Dommann "Companies on the NANO sector" STAB Scientific Technological Advisory Board, Vienna, Vienna, AU, December 2007 A. Dommann "Crystallography on perfect crystals" 10th Anniversary of the BENEFRI Crystallography Service, Neuchatel, CH, November 2007 A. Dommann "CSEM, a strategic Partner of Ciba" Ciba R&D Conference 2007, Basel, Basel, CH, November 2007 A. Dommann "Future of Comlab" 5th European Mechatronics Meeting, Grand- Bornand, FR, June 2007 A. Dommann "Innovative X-Ray techniques to characterize VLSI" SIMTech - Joint Swiss-Singapore Workshop on Sensors for Harsh Environments, Singapore, SG, January 2007 A. Dommann "Long term stability of MEMS" NanoScience 2007, Lichtenwalde/Sachsen, DE, October 2007 A. Dommann "MEMS for Cars" VW Seminar, Wolfsbrurg, DE, March 2007 A. Dommann "MEMS Reliability for Space" First CEAS European Air and Space Conference, Berlin, DE, September 2007 A. Dommann "More than Moore and MEMS" ENIAC Initiative, IBM Research Centre, Rüschlikon, CH, November 2007 A. Dommann "New horizons in Coatingtechnology" CCMX-Day, Fribourg, CH, March 2007 A. Dommann "New techniques to determine aging on MEMS" Panalytical-Meeting, Almelo, NL, November 2007 A. Dommann "Polymer MEMS for Medical Purposes" SSB Conference, Neuchatel, CH, May 2007 114

A. Dommann "Possible collaboration models in the field of MEMS with CSEM" MicroNanoFabrication Annual Meeting, EPFL, Lausanne, CH, May 2007 A. Dommann "Reliability for MEMS in Space" ESTEC, Noordwijk, NL, April 2007 A. Dommann "Sensors and Nanotech Today" Mettler-Toledo Wrap-Up 2007, Greifensee, CH, November 2007 A. Dommann "X-Ray Analysis on thin films" EMPA-Conference, Dübendorf, CH, May 2007 M.-A. Dubois, C. Billard, G.Parat, M. Aissi, H. Ziad, J.-F. Carpentier, K.B. Östman "Above-IC Integration of BAW Resonators and Filters for Communication Applications" Invited paper at 3rd International Symposium on Acoustic Wave Devices for Future Mobile Communication Systems, Chiba, JP, March 2007 M.-A. El Mechat "Realization of multi-3d-tof camera environments based on coded-binary sequences modulation " Optical 3D Measurement Techniques, Zurich, CH, July 2007 M. El-Khoury, J. Krauss "International Conference on Portable Information Devices" IEEE Portable 2007, Orlando, US, March 2007 C. C. Enz, J. Chabloz, J. Baborowski, C. Muller, D. Ruffieux "Building Blocks for an Ultra Low-Power MEMSbased Radio" IEEE Int. Workshop on Radio-Frequency Integration Technology (inveted), Singapore, SG, December 2007 J. R. Farserotu "ehealth" ehealth, Neuchatel, CH, March 2007 J. R. Farserotu "International Symposium on Medical Information and Communication Technology 2007" ISMICT 07, Oulu, FI, December 2007 P. Ferrat, C. Gimkiewicz, S. Neukom, Y. Zha, A. Brenzikofer, Th. Baechler "Ultra-miniature camera module with omnidirectional view for collision avoidance" Workshop Micro Aerial Vehicles: Design, Control and Navigation at IROS conference, San Diego, US, November 2007 M. Fretz "Comsol Conference" Poster Session, Grenoble, FR, October 2007 P. Glocker "NEMO-07 Anwenderforum" Micromontageplattform, Frankfurt a.m., DE, May 2007 S. Graf, P. Schmid, T. Stöckli, N. Schmid, H. F. Knapp "Novel Approach of integrating microrobotics and microfluidics in cell based assays" MipTec Poster Session, Basel, CH, May 2007 E. Grenet "Embedded high dynamic range vision system for real-time driving assistance" Sensorik für Fahrerassistenzsysteme, Heilbronn, DE, September 2007 C. A. Griffiths, S. Bigot, E. Brousseau, M. Heckele, J. Nestler, J. Auerswald "4M 2007 Conference on Multi-Material Micro Manufacture" Process Characterisation including Process Chains, Borovets, BG, October 2007 E. Györvary "The way to Brazil; The different units in Belo; The aims of CSEM Brasil" Swiss Innovation Academy, Neuchatel, CH, July and October 2007 E. Györvary "Life Sciences at CSEM" Innovation Day at FIEMG, Belo Horizonte, Minas Gerais, BR, March 2007 E. Györvary "Wearable Electronics and Textile Applications" Textile Seminar ABIT, São Paolo, BR, March 2007 H. Heinzelmann "CSEM and CSEM Brazil Innovation Center" Textile Seminar ABIT, São Paolo, BR, March 2007 115

H. Heinzelmann "CSEM and CSEM Brazil Innovation Center" Innovation Day at FIEMG, Belo Horizonte, Minas Gerais, BR, March 2007 H. Heinzelmann "Nanotechnology meets IEP" International Executive Program 2007, INSEAD, Fontainebleau, FR H. Heinzelmann "Block Copolymer Lithography" NordForsk Summer School on Polymer Micro- and Nano- Fabrication, Palmse, EE, September 2007 H. Heinzelmann "Research & Project Management" NordForsk Summer School on Polymer Micro- and Nano- Fabrication, Palmse, EE, September 2007 H. Heinzelmann "Engineering for Life Sciences" Swiss Society of Biomedical Engineering 2007, Neuchatel, CH, September 2007 H. Heinzelmann "Micro- and Nano- Tools" Swiss Innovation Academy, Neuchatel, CH, July and October 2007 T. Heldal, T. Volden, J. Auerswald, H.F. Knapp "NSTI Nanotech 2007, 10th Annual Nanotechnology Conference and Trade Show" Micro and Nano Fluidics, Santa Clara, US, May 2007 S. Henein "7th International Conference of the European Society for Precision Engineering & Nanotechnology" EUSPEN, Bremen, DE, May 2007 K. Hiller, T. Gessner, J. Nestler, J. Gavillet, S. Getin, E. Quesnel, S. Martin, G. Dellapierre, J. Soechtig, G. Voirin, L. Buergi, J. Auerswald, H.F. Knapp, S. Ross, S. Bigot, M. Ehrat, A. Lieb, M.-C. Beckers, D. Dresse "Smart Systems Integration Conference" Special Aspects of Integration, Paris, FR, March 2007 T. Hinderling "Le projet Solar Islands" Energissima, Bulle, CH, June 2007 T. Hinderling "Sensors at CSEM" SIMTech - Joint Swiss-Singapore Workshop on Sensors for Harsh Environments, Singapore, SG, January 2007 A. Hutter "DAta Systems In Aerospace" DASIA 2007, Naples, IT, May-June 2007 R. Kern, et al. "High Throughput Material Testing Apparatus HTA-7" ICOE07, Eindhoven, NL, May 2007 G. Kotrotsios "Environmental monitoring using ultra low power wireless communication systems" Greater Nagoya Initiative, Tsu-City. Mie prefecture, JP, January-February 2007 G. Kotrotsios "ResearchTransfer to create Business start-ups" High-level Conference on Nanotechnologies, Braga, PT, November 2007 R. Krähenbühl, A.-C. Pliska, R. Bauknecht, S. Aiterrami, A. Peterhans, A. Stump, K. Krasnopolski, J. Kunde, C. Bosshard "CTI day in Micro and Nano technologies" Neuchatel, CH, November 07 Q. Lai, T. Burch, S. Grossmann, A. Stump, K. Krasnopolski, M. Busse-Grawitz, D. Fengels, C. Böhler, T. Bragagna, A. Heinrich, S. Gross, S. Summer, B. Nussbaumer, G. Boer "CTI Medtech Award 2007 Nominee Presentation" The LEDDT TM - Platform (Laser Easy Drug Delivery Technology), a novel injection-free method for intraepidermal delivery of large molecular weight drugs., Bern, CH, September 2007 J. Luprano "New generation of smart sensors for biochemical and bioelectrical applications" phealth-2007, Chalkidiki, GR, June 2007 J. Luprano "29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society" EMBC2007, Lyon, FR, August 2007 J-M. Mayor "ITER Business Forum" ITER, Nice, FR, December 2007 116

A. Meister "Fluidic nanoprobe patterning" NaPa Day 2007, Berlin, DE, October 2007 J.-L. Nagel "Biometric face authentication on mobile devices" Invited Presentation, Conference on Biometrical Feature Identification and Analysis, Goettingen, DE, September 2007 J. Nestler, A. Morschhauser, K. Hiller, J. Auerswald, H.F. Knapp, T. Otto, T. Gessner "Smart Systems Integration Conference" Poster Session, Paris, FR, March 2007 J. Nestler, A. Morschhauser, K. Hiller, S. Bigot, J. Auerswald, J. Gavillet, T. Otto, T. Gessner "11th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS)" Microfluidics - Aliquoting,Mixing & Pumping, Paris, FR, October 2007 V. Neuman "Bio-Innovation Day 2007" BioInnovationDay07, Lausanne, CH, November 2007 P. Niedermann "Comlab as a Tool for Industrial MEMS Development" MicroNanoFabrication Annual Review Meeting, Lausanne, CH, May 2007 E. Onillon "IEEE/ASME International Conference on Advanced Intelligent Mechatronics" AIM 2007, Zurich, CH, September 2007 J. Osmond, G. Isella, D. Chrastina, R. Kaufmann, H. von Känel "Ge/Si (100) heterojunction photodiodes fabricated from material grown by low energy plasma enhanced chemical vapor deposition" 5th International Conference on Silicon Epitaxy and Heterostructures (ICSI-5), Marseille, FR, May 2007 S. Pasche, R. Ischer, G. Voirin, M. Liley, J. Luprano "Wearable biosensors for monitoring wound healing" phealth 2007, Porto-Carras, GR, June 2007 S. Pasche, R. Ischer, G. Voirin "Biochemical sensors at CSEM" Proetex Workshop, Gent, BE, September 2007 S. Pasche, R. Ischer, S. Angeloni, M. Liley, J. Luprano, G. Voirin "Wearable Biosensors for Health Monitoring" Biosurf VII Functional Interfaces for Directing Biological Response, Zurich, CH, August 2007 A. Perret "SSI Overview and Perspective Smart Systems and Applications" Euripides Forum, Versailles, FR, June 2007 A. Perret "HTA General presentation" SSI Conference, Paris, FR, March 2007 A. Perret "HTA, Heterogeneous Technology Alliance" Annual Review Leti, Grenoble, FR, June 2007 A. Perret "MEMS at CSEM - MEMS Fab Brazil" Innovation Day at FIEMG, Belo Horizonte, Minas Gerais, BR, March 2007 A. Perret "HTA General Presentation" Smart System Integration Conference, Paris, FR, March 2007 A. Perret "MEMS" Workshop on MEMS, Belo Horizonte, BR, March 2007 A. Perret "Micro-nano technology in Western Switzerland" Development Economique Western Switzerland, Stuttgart, DE, September 2007 A. Perret "SSI Overview and Perspective Smart Systems and Applications" Euripides Forum, Versailles, FR, June 2007 C. Pickering, M. McNie, C. Reeves, T. Harvey, T. Ryan, C. Bosshard, H.F. Knapp, G. Schröpfer, F. von Germar, T. Bauer, P. Janus, P. Gabriec, C. Moldovan, B. Firtat, A. Richardson "Smart Systems Integration Conference" Smart Systems: Design, technologies and integration, Paris, FR, March 07 C. Piguet "Awareness Applications and the Related System Architectures" Invited Embedded Tutorial at DATE 07, Nice, FR, April 2007 117

C. Piguet "High Level Energy and Power Reduction Strategies" Invited Talk at CLEAN Workshop, Munich, DE, September 2007 C. Piguet "Histoire des microprocesseurs horlogers" FTFC Journées Faible Tension Faible Consommation, Paris, FR, May 2007 C. Piguet "La conception de SoC pour des réseaux de capteurs" FETCH 2007, Villard de Lans, FR, January 2007 C. Piguet "Low Power Design in Deep Submicron 65 & 45 nm Technologies" ICECS 07, Marakesh, MA, December 2007 C. Piguet "Total Energy and Total Power Reduction at Architectural Level" Invited Talk at CLEAN Workshop, Stresa, IT, March 2007 A.-C. Pliska, R. Bauknecht, R. Krähenbühl, A. Peterhans, A. Stump, S. Aiterrami, C. Bosshard, J. Kunde "Smart Systems Integration Conference" Microsystems Packaging and System Integration, Paris, FR, March 07 A.-M. Popa, J. Polesel Maris, R. Pugin, H. Heinzelmann "Force spectroscopy in liquid media - an AFM study of nanostructured surfaces functionalized with responsive molecules" SAOG, Fribourg, CH, January 2008 A.-M. Popa, J. Polesel Maris, R. Pugin, H. Heinzelmann "AFM characterisation of responsive nanostructured surfaces" Joint workshop of the Marie Curie Research and Training Networks POLYAMPHI and BIOPOLYSURF and the ESF EUROCORES project BIOSONS, Biarritz, FR, February 2008 R. Pugin "Nanotechnology and Textiles" Textile Seminar ABIT, São Paolo, BR, March 2007 R. Pugin "Nanotechnology at CSEM" Innovation Day at FIEMG, Belo Horizonte, Minas Gerais, BR, March 2007 M. Ramuz, et al. "Patterning of polymer light-emitting devices by a printing method " Workshop Innovations in Inkjet Polymers for Biomaterials and Nanoparticles, Eindhoven, NL, June 2007 J. Rousselot "12th IEEE Symposium on Computers and Communications " ICC 2007, Aveiro, PT, July 2007 J. Rousselot "European Ultra Wide Band Radio Technology Workshop" UWB 2007, Grenoble, FR, May 2007 A. S. Roy, C. C. Enz "A Charge-Based Compact Flicker Noise Model Including Short-channel Effects" NSTI Nanotech - Workshop on Compact Modeling (WCM 2007), Santa Clara, US, May 2007 A. S. Roy, C. C. Enz, J.-M. Sallese "Theory of Source-Drain Partitioning in MOSFET" NSTI Nanotech - Workshop on Compact Modeling (WCM 2007), Santa Clara, US, May 2007 A. S. Roy, C. C. Enz "An Analytical Thermal Noise Model of DG MOSFET and Comparison with Bulk MOSFET" Int. Conf. on Noise and Fluctuations (ICNF), Tokyo, JP, September 2007 A. S. Roy, C. C. Enz "Analytical Noise Modeling in MOSFET" Int. Conf. on Noise and Fluctuations (ICNF, Tokyo, JP, September 2007 P.-F. Rüedi, E. Grenet, F. Lustenberger "Battery powered high dynamic range vision system" ISCAS, New Orleans, US, May 2007 P.-F. Rüedi "High dynamic range vision sensor for embedded applications" Workshop on Image sensors analog and digital onchip processing, Toulouse, FR, November 2007 P.-F. Rüedi "High dynamic range vision sensor for embedded applications" Image sensor analog and digital on-chip processing, Toulouse, FR, November 2007 118

E. Scolan, V. Monnier, R. Pugin "Nanostructured sol-gel surfaces" Colloque Solgel 2007, Tours, FR, February 2007 E. Scolan, V. Monnier, R. Pugin "Nanostructured sol-gel surfaces" International Sol-Gel Workshop 2007, Montpellier, FR, September 2007 P. Seitz, S. Beer, Y. Delley "Smart pixel array for the simultaneous detection of phase and amplitude envelope, enabling real-time nanometer-precision OCT" Frontiers of Electronic Imaging, World of Photonics 2007, Munich, DE, June 2007 P. Seitz "Business Value Creation The CSEM Innovation Center Model" ETH Project Presentations for the Official Singapore Delegation, Zurich, CH, October 2007 P. Seitz "Change Management" Swiss Innovation Academy, Neuchatel, CH, September 2007 P. Seitz "Creativity" Swiss Innovation Academy, Neuchatel, CH, July 2007 P. Seitz "Das CSEM Forschungszentrum für Nanomedizin in Landquart" Unternehmertreff im Alpenrheintal, Maienfeld, CH, June 2007 P. Seitz "Didactics, Presentations and Publications" Swiss Innovation Academy, Neuchatel, CH, July 2007 P. Seitz "Europhot The European Initiative for Single- Photon Electronic Imaging" Europhot Presentation, Unit Head Photonics, Bruxelles, BE, February 2007 P. Seitz "Lab-on-a-Chip Using Organic Semiconductors" 4th Optoelectronic and Photonic Winter School on Biophotonics, Trento, IT, March 2007 P. Seitz "Lab-on-a-Chip Using Organic Semiconductors" Swiss Innovation Academy, Neuchatel, CH, July 2007 P. Seitz "Moderne Halbleiter-Bildsensorik" Intensive industrial training course, Hamburg, DE, July 2007 P. Seitz "Nanomedicine in Europe and in Switzerland" Biomedical Workshop, Inselspital, Bern, CH, February 2007 P. Seitz "Nanomedizin Wissenschaftsgebiet mit enormem Zukunftspotential" CSEM Innovation Day, Zurich, CH, November 2007 P. Seitz "Optical Biochips" 4th Optoelectronic and Photonic Winter School on Biophotonics, Trento, IT, March 2007 P. Seitz "Optical Biochips Basics" Swiss Innovation Academy, Neuchatel, CH, July 2007 P. Seitz "Photon-Noise Limited Distance Resolution of Optical Metrology Methods" SPIE Conference on Optical Metrology, Munich, DE, June 2007 P. Seitz "The Art of Happiness at Work" Swiss Innovation Academy, Neuchatel, CH, September 2007 P. Seitz "The Grand Challenges of Photonics (General Chair and Moderator)" EOS Conference on Photonics, World of Photonics 2007, Munich, DE, June 2007 P. Seitz "The history of optical time-of-flight techniques for 3D imaging " Frontiers of Electronic Imaging, World of Photonics 2007, Munich, DE, June 2007 P. Seitz "Tiens, vous voulez faire une carrière scientifique" Atelier du Laboratoire Européen Associé en Microtechnique, Arc-et-Senans, FR, September 2007 J. Solà I Caros "4th International Workshop on Wearable and Implantable Body Sensor Networks" BSN 07, Aachen, DE, March 2007 119

J. Solà I Caros "Annual meeting of the Swiss Society of Biomedical Engineering" SSBE 2007, Neuchatel, CH, September 2007 R. P. Stanley Workshop on Photonic Crystals, Prague, CZ, April 2007 R. Steiger "New devices based on nanoparticulate, mesoporous metal oxide coatings" International Conference on Nanotechnology and Advanced Materials, Hong Kong, CN, December 2007 G. Suarez, S. Pasche, G. Voirin, Y. Leterrier, A. Sayah "Lab-On-Chip for Analysis and Diagnostics" CCMX First Annual Meeting, Fribourg, CH, March 2007 R. Vetter "9th Meeting of the European Federation of Autonomic Societies 18th Meeting of the American Autonomic Society 2nd Joint Meeting EFAS - AAS" EFAS 2007, Vienne, AT, October 2007 G. Voirin, R. Ischer, M. Ramuz, L. Bürgi, R. P. Stanley, D. Leuenberger, J. Söchtig, C. Winnewisser "SEMOFS: Micro-Optical Platform for Plasmon Sensing" SEMOFS Workshop, Borovets, BG, October 2007 G. Voirin, J. Söchtig, L. Buergi, R. P. Stanley, S. Getin, E. Quesnel, B. Fillon, J. Gavillet, S. Bigot, M. Ehrat, A. Lieb "m-optics technologies" SEMOFS Workshop, Borovets, BG, October 2007 G. Voirin, G. Dudnik, J. Luprano "Advanced e-textiles for firefighter and civilian victims" 3rd Global Plastic Electronics Conference & Showcase, Plastic Electronics Foundation, DE, October 2007 B. Wenger, M.-H. Song, N Tétreault, R. H. Friend "Tunability of flexible polymer distributed feedback lasers" International Symposium on Ultrafast- and Nano- Optics, Beijing, CN, October 2007 C. Winnewisser "Integrated Optoelectronic Systems based on Solution Processed Polymeric Semiconductor Materials" NanoEurope 2007, St. Gallen, CH, September 2007 C. Winnewisser "Towards Integrated Photonic Systems based on organic Semiconductor Materials" Plastic Electronics 2007, Frankfurt, DE, October 2007 Q. Xu, J. R. Farserotu, J. Ayadi, J. F. M. Gerrits "18th Annual IEEE International Symposium, on Personal, Indoor and Mobile Radio Communications" IEEE PIMRC 07, Athens, GR, September 2007 H. Zhan "10th International Symposium on Wireless Personal Multimedia Communications" WPMC 07, Jaipur, IN, December 2007 120

Competence Centre for Materials Science and Technology (CCMX) and National Center of Competence in Research (NCCR) Projects CCMX-MMNS Lab-on-a-chip for Analysis and Diagnostics NCCR Module 5 Functional Materials by Hierarchical Self-Assembly (proposal for last financing round) Swiss Commission for Technology and Innovation (CTI) 8704.1 NMPP-NM ALDEBARAN A low-power 2.4 GHz CMOS radio transceiver IC for the Wibree standard 8035.2 ARGUS Hochintegrierter 1.3 Mpixel Bildsensor mit hoher optischer Sensitivität für eine Hochgeschwindigkeits-Kameraanwendung 8759.1 EPRP-IW COATING ENGINEERING Engineering of thin film crystallinity of wear resistant coatings using a combination of PECVD and PVD plasma technology 7796.1 DIXI Digital Phase Contrast Imaging for Medical DiagnosticsOK 8272.1 NMPP-NM DMS Digital motion sensor 8039.2 NMPP-NM DOSENS II Development of a new dissolved oxygen sensor for activated sludge monitoring based on a membrane-less, self-calibrating, self-cleaning microdisk array sensing electrode 8627.2 El PICA Custom designed organic electroluminescent pictograms for pushbutton applications 9032.1 PFIW-IW FMM Feeding Module for Microfactory 8227.1 HELIOCT Entwicklung einer neuartigen Mikroskopie-Technologie zur 3D Bildgebung in Echtzeit 8247.2 LSPP-LS IOS ios Development of an implant to place on the bones of people touched by the Parkinson disease in order to decrease the symptoms 8018.2 LSPP-LS LASETIME The LEDDT Platform (Laser Easy Drug Delivery Technology), a novel injection-free method for intraepidermal delivery of large molecular weight drugs. 7963.1 LONGLITE Aging mechanisms and numerical device physics of organic LEDs 7482.2 MEMSORS Micro-machined Electrostatic Sensors for acoustic Sensors 8452.1 NMPP-NM MICROS Entwicklung eines neuartigen miniaturisierten Linearencoders optimiert für den Einsatz mit lasergeschriebenen Massstäben 8325.1 NIMROD Nicht-invasive Messung der Retina ohne Dilatation 8648.1 PERTEST Pre-Employment and Rehabilitation Tester 7474.2 NMPP-NM POLITE New electroluminescent polymers for large area lighting applications 8037.2 NMPP-NM POWERPACK Low-cost packages for ultrabright light sources 9146.2 PFIW-IW PTMR Pseudo Tactile Microassembly Robotics 9119.1 ROVARP Rotationsvariable Farbpigmente 8621.2 SCL ll Smart Compliance Labels 121

8241.2 DCPP-NM SOLID Solid on Liquid Deposition 8817.1 NMPP-NM VENUS An integrated radio solution for ultra low-power wireless wristwatches, automotive remote-controls, and wireless sensor network applications 7843.2 NMPP-NM WOME Study and conception of a low power, reconfigurable OFDM modem for multimode wireless broadband communications. WOME : Wireless OFDM Multimode Engine 7804.1 XCAN Röntgen-Detektoren mit Einzelphoton-Detektion European Community Projects FP6 NMP µsapient Synergetic Process Integration for Efficient Micro and Nano Manufacture FP6 IST ARTTS Action Recognition and Tracking based on Time-of-flight Sensors FP6 IST MOBILITY BIOPOLYSURF Engineering advanced polymeric surfaces for smart systems in biomedicine, biology, material science and nanotechnology: A crossdisciplinary approach of biology, chemistry and physics FP6 IST NMP BIOTEX Bio-sensing Textile for Health Management FP6 SUSTDEV HOLISTIC Holistic Optimisation Leading to Integration of Sustainable Technologies in Communities FP6 IST CRUISE CReating Ubiquitous Intelligent Sensing Environments FP6 NMP DIPNA Development of an Integrated Platform for Nanoparticle Analysis to verify their possible toxicity & the eco-toxicity FP6 INFRASTRUCTURES EARLINET-ASOS European Aerosol Research Lidar Network: Advanced Sustainable Observation System FP6 IST e-sense Capturing Ambient Intelligence for Mobile Communications through Wireless Sensor Networks FP6 IST GOODFOOD Food Safety and Quality Monitoring with Microsystems FP6 NMP HYDROMEL Hybrid Ultra-Precision Manufacturing Process Based on Positionaland Self-assembly for Complex Micro-Products FP6 NEST IDEA Imaging device for electrophysiological activity monitoring of neuronal cell cultures FP6 IST INTEGRAMplus Integrated MNT Platforms & Services Interreg LEA LEA-2006-2007 Laboratoire Européen Associé pour la formation et le transfert de la technologie dans le domaine de la Microtechnique FP6 IST MAGNET BEYOND My personal Adaptive Global Network Beyond FP6 SME MAP2 Micro-Architectural Power management: Methods, Algorithms and Prototype tools FP6 NMP MEDITRANS Targeted delivery of nanomedicine COST MIE-OPIC Mie Resonances in Opal Photonic Crystals FP6 IST MINAMI Micro-Nano integrated platform for transverse Ambient Intelligence applications 122

FP6 INFRASTRUCTURES MNT Europe Staircase towards European MNT Infrastructure Integration FP6 IST MUFLY Fully Autonomous Micro Helicopter FP6 IST NANOHAND Micro-nano System for Automatic Handling of Nano-objects FP6 NMP NANOSAFE2 Safe production and use of nanomaterials FP6 NMP NANOSECURE Advanced nanotechnological detection and detoxification of harmful airborne substances for improved public security FP6 NMP NAPA Emerging nanopatterning method FP6 NMP NAPOLYDE Nano-structured polymer deposition processes for mass production of innovative systems for energy production & control and for smart devices FP6 IST NEMO EU Network of Excellence: Micro-Optics FP6 NMP NEWBONE Development of load-bearing fibre reinforced composite based nonmetallic biomimetic bone implant FP6 INFRASTRUCTURES OPTICON Optical Infrared Coordination Network for Astronomy FP6 IST Phodye New Photonic systems on a chip based on dyes for sensor applications scalable at wafer fabrication FP6 IST PLASMO-NANO-DEVICES Surface plasmon nanodevices Towards sub-wavelength miniaturization of optical interconnections and photonic components FP6 IST PLEAS Plasmon Enhanced Photonics FP6 IST PROETEX Protection e-textiles: MicroNanoStructured fibre systems for Emergency- Disaster Wear FP6 IST PULSERS Pervasive Ultrawideband Low Spectral Energy Radio Systems FP6 IST ROLLED Roll-to-roll manufacturing technology for flexible OLED devices and arbitrary size and shape displays FP6 IST SCIER Sensor and Computing Infrastructure for Environmental Risks FP6 SUSTDEV SCOUT-O3 Stratospheric-climate links with emphasis on the UTLS (SCOUT-O3)- EC 505390-GOCE-CT-2004 FP6 IST NMP SEMOFS Surface enhanced micro optical fluidic systems FP6 IST NMP SMARTHEALTH Smart Integrated Biodiagnostic Systems for Healthcare FP6 IST WASP Wirelessly Accessible Sensor Populations FP6 AEROSPACE WISE Integrated wireless sensing European Space Agency (ESA), European Southern Observatory (ESO) and Astrophysical Instrument Projects ESA Projects GSTP LIDAR PRN Laser Diode caracterisation at 779 nm (ESA Technological Program GSTP-4) Development of Pseudo-Random Noise continuous-wave Lidar Prototype (ESA Technological Program GSTP-4) 123

LISA-PAAM LTMS-2 OSCAR OSCC SHM SPHERE SPHM ESO Projects ELT-M5-FSU PRIMA-DDL Development, demonstration manufacturing and test of a closed loop controlled, pico-radians resolution, tiltmirror, as Point Ahead Angle Mechanism for the ESA LISA-LPT Long Term Medical Survey system ground prototype Ultrastable Atomic Beam Clock for Telecom Space Applications and Long-Term Space Missions (ESA Technological Program ARTES-5) Development of an Optically Pumped Space Cesium Clock (ESA Technological Program ARTES-5) Development of Space Hydrogen Maser for ACES Reaction sphere for attitude control Design Consolidation, Industrialisation and Lifetime Qualification of a Physics Package for a Passive Hydrogen Maser (PHM) (Galileo System Test Bed Version 2, GSTB-V2) Development, demonstrator manufacturing and test of a Field Stabilisation Unit (FSU) for the M5 mirror on the future ELT (Extremely Large Telescope, 40 m) of ESO Systems engineering for the development, manufacturing, test and integration of a Differential Delay Line (DDL) for the PRIMA instrument of the ESO-VLT (Very Large Telescope) interferometer line at Cerro Paranal, Chile Astrophysics Projects EMIR-DTU Development, manufacturing and test of a Detector Translation Unit (DTU) for the EMIR instrument on the Gran Canaries Telescope (GTC) of Spain (IAC, Instituto de Astrofisica de Canaries) MOSFIRE CSU Development, manufacturing, test and integration of a Configurable Slit mask Unit for the Multi-Object Spectrometer for Infra-Red Exploration Instrument (MOSFIRE) to be mounted on the W.M. Keck Observatory Telescope, Hawaii USA Industrial Property Creativity In 2007, 34 invention reports were submitted for examination. Patent portfolio CSEM inventions have led to 23 patent applications in 2007 (13 regular applications and 10 US provisional applications). The patent portfolio has been further enhanced by the extension of different countries of 21 patent files based on prior patent applications. Collaboration with Research Institutes and Universities University Institute Professor Field of collaboration CEA LETI J.-R. Lequepeys Leakage reduction, processor EPF Lausanne Advanced Photonics Laboratory R. Salathé Biochemical Nanofactory EPF Lausanne CMI Center of MicroNanotechnology C. Hibert Etching and nanofabrication EPF Lausanne CSI G. De Micheli CCMX leakage reduction EPF Lausanne Institut de chimie physique H. Vogel Fluorescent Nanoparticles EPF Lausanne Laboratoire de microsystèmes 2 M. Gijs Lab-On-A-Chip EPF Lausanne Laboratory for regenerative medicine and pharmacobiology J. Hubbell Generic scavenger powered DSPbased SoC for emerging implantable biosensors and bioactuators EPF Lausanne LAP P. Ienne Processor 124

University Institute Professor Field of collaboration EPF Lausanne LEG M. Declercq Medical, processor EPF Lausanne LPM2 P. Ryser Medical, processor EPF Lausanne LSM Y. Leblebici CCMX leakage reduction EPF Lausanne Nanoengineering J. Brugger Nanoscale structuring, nanofabrication EPF Lausanne Nanostructuring Research Group P. Hoffmann Block copolymer self-assembly. Design of templated and chemically modified surfaces EPF Lausanne STI-LMIS 4 P. Renaud Superparamagnetic Nanoparticles EPF Lausanne STI-IMX-Ceramics P. Muralt Sensors EPF Lausanne STI-IMX-LTP H. Hofmann Ceramics ETH Zurich BioInterfaceGroup M. Textor Parylene ETH Zurich Department of electrical engineering J. Vörös AFM on cells ETH Zurich Department of materials H. Hall-Bozic Biomaterials ETH Zurich Institut für Atmosphäre und Klima T. Peter Lidar Measurements from Highaltitude aircraft ETH Zurich Institute of Mechanical Systems E. Mazza Reliability of Silicon MEMS ETH Zurich Laboratorium für Organische Chemie F. Diederich Dendrimer self-assembly ETH Zurich Laboratory for Surface Science and Technology N.D. Spencer, M. Textor Polymer nanostructuration ETH Zurich Nanotechnology Group A. Stemmer Automated Cell Injection HE ARC Microtechnique H. Keppner Parylene TU Berlin / IZM Berlin Micro Materials Centers Berlin B. Michel Reliability of Silicon MEMS Uni Ulm Institut für Mikro- und Nanomaterialien H. Fecht Reliability of MEMS University Hospital Zurich University Hospital Zurich University Hospital Zurich Neonatology M. Wolf Near infrared spectroscopy Nuclear Medicine B. Weber Brain imaging and OCT Nuclear Medicine A. Buck Fluorescent Probes University of Mulhouse Institut de Chimie des surfaces et interfaces ICSI G. Reiter Polymers self-assembly University of Neuchatel IMT A. Neels, H. Stoeckli-Evans Crystallography University of Neuchatel IMT H.-P. Herzig Packaging University of Neuchatel IMT N. F. de Rooij MEMS University of Neuchatel IMT N. F. de Rooij Digital motion sensor 125

University Institute Professor Field of collaboration University of Neuchatel IMT P.-A. Farine Leakage reduction University of Neuchatel IMT, SAMLAB M. Koudelka-Hep Micro-electrode arrays University of Neuchatel Institut d Hydrogéologie E. Verrecchia NP screening by mass spectroscopy University of Neuchatel Institut de Microtechnique T. Bürgi Surface chemistry characterization by IR based spectroscopy University of Neuchatel Institut de Zoologie (Parasitologie) B. Betschart Cell biology University of Ulm Inorganic Chemistry I N. Hüsing Mesoporous sol-gel thin films Vienna University of Technology Applied inorganic chemistry group of the institute of material chemistry U. Schubert Sol-gel processes Vienna University of Technology Institute of Materials Chemistry U. Schubert Metallic nanoparticles doped nonporous layers ZHW CCP H. Schwarzenbach PLEDs Teaching Title of lecture Context Location J. Auerswald Werkstoffe der Elektrotechnik Werkstoffkunde Vorlesung HSLU T&A, Luzern N. Blanc Méthodes de détection optique Institut de Microélectronique et Microsystèmes EPF Lausanne Photo & Machine Vision Institute of Geodesy and Photogrammetry ETH Zurich C. Bosshard Assembly and Packaging Swiss Innovation Academy CSEM Alpnach Nonlinear Optics ETH Zurich Zurich (Non)linear Optical Spectroscopy: Basics and Applications ETH Zurich Zurich L. Bürgi Organic Optoelectronics Swiss Foundation for Research and Microtechnology (FSRM) Summerschool Highlights in Microtechnology" 2005 Neuchatel E. Charbon and P. Seitz Modern solid-state image sensing Master Program in Electrical Engineering EPF Lausanne A. Dommann Aging measurements on microstructures BeNeFri - HRXRD Workshop CSEM Neuchatel MEMS technologies Swiss Innovation Academay CSEM Neuchatel Coating Technologies Universitärer MNT-Master Dornbirn Coating Technologies and X-Ray Analysis High Resolution X-Ray Diffraction on thin films MNT-Masterstudiengang CCMX-PhD Seminar Dübendorf Luzern C. C. Enz Advanced Analog and RF IC Design I Master in Microelectronics EPF Lausanne 126

C. C. Enz Title of lecture Context Location Advanced Analog and RF IC Design II Master in Microelectronics EPF Lausanne MOS Transistor Modeling for Low- Voltage and Low-Power Circuit Design Low-Voltage, Low-Power Analog CMOS IC Design EPF Lausanne Trade-offs in Designing LP-LV RF Transceivers in Standard Digital CMOS Low-Voltage, Low-Power Analog CMOS IC Design EPF Lausanne MOS Transistor Modeling in Deep Submicron Practical Aspects in Mixed-Mode ICs EPF Lausanne MOS Transistor Modeling for RF IC Design RF Analog IC Design EPF Lausanne Low-Frequency Noise Reduction Techniques Low-Noise, Low-Offset Analog IC Design EPF Lausanne High-Frequency Noise Low-Noise, Low-Offset Analog IC Design EPF Lausanne J. R. Farserotu Satellite Communication System and Networks chargé de cours, systèmes de communication and Space Technology EPF Lausanne Executive Master in egovernance, egov Eservices from the sky and satellite systems 18 July 2007 EPF Lausanne RF signals and test 18 April 2007 FSRM, Neuchatel E. Györvary The way to Brazil The different units in Belo Horizonte The aims of CSEM Brazil Swiss Innovation Academy CSEM Neuchatel H. Heinzelmann Micro-and Nano Tools Swiss Innovation Academy CSEM Neuchatel Research & Project Management NordForsk Summer School on Polymer Micro- and Nano- Fabrication Tallinn, Estonia Block Copolymer Lithography NordForsk Summer School on Polymer Micro- and Nano- Fabrication Tallinn, Estonia S. Henein Construction (Precision Machine Design) Students in Microtechnology, 1st year (2 hours/week) Bern University of Applied Science Composants Microtechnques (Microtechnoloy Components) Students in Microtechnology, 2nd and 3rd year (4 hours/week) Bern University of Applied Science Flexure-based Mechanisms for High Precision 4 hours Tutorial in the frame of the 7th International Conference of the European Society for Precision Engineering & Nanotechnology Bremen, Germany Conception des guidages flexibles Formation continue FSRM, Neuchatel H. F. Knapp Microfluidics Swiss Innovation Academy Lecture CSEM Neuchatel M. Liley AFM for Life Sciences Swiss Innovation Academy CSEM Neuchatel AFM for Life Sciences Summer School Highlights in Microtechnology Neuchatel 127

Title of lecture Context Location R&D with Industry: what makes a good project 3rd BioPolySurf Summer School Ovronnaz M. Liley Nanotoxicology Masters in nanotechnology University of Neuchatel A. Meister Fluidic nanopatterning Doctoral course MEMS and nanotechnology EPF Lausanne Nanoscale dispensing of ultrasmall droplets 3rd BioPolySurf Summer School Ovronnaz Nanoscale dispensing of ultrasmall single droplets PANAMA summer school Toulouse, France P. Niedermann Project presentation Swiss Innovation Academy CSEM Neuchatel Process definition and realisation Swiss Innovation Academy CSEM Neuchatel T. Overstolz Optical Switch Characterization Swiss Innovation Academy CSEM Neuchatel C. Piguet Design for Leakage Reduction Advanced CMOS IC Design EPF Lausanne Microélectronique pour Systèmes sur Chips Evolution de la microélectronique et SoC EPF Lausanne HES-SO EIF Microelectronic Technology ALaRI Course on Embedded Systems University of Lugano Ultra-Low Power Circuit Design University of Neuchatel Digital IC and SoC Design University of Neuchatel A.-C. Pliska Integration in Microelectronics Packaging Swiss Innovation Academy CSEM Alpnach E. Scolan Sol-gel made nanoporous layers for sensing applications EU-project NAPOLYDE Midterm workshop CEA, Grenoble, France P. Seitz Entrepreneurship Master Program in Micro and Nano Sciences University of Neuchatel Solid-state image sensors Master Program in Micro and Nano Sciences University of Neuchatel Management des Projets R&D Bachelor Program in Micro and Nano Sciences University of Neuchatel G. Spinola IC Package Design & Reliability with CAE Swiss Innovation Academy CSEM Alpnach C. Urban Méthodes de détection optique Institut de Microélectronique et Microsystèmes EPF Lausanne Photo & Machine Vision Institute of Geodesy and Photogrammetry ETH Zurich M. Wannemacher Informationssysteme Bachelor Course HSLU T&A, Luzern 128

Title of lecture Context Location C. Winnewisser Polymer Optoelectronic Technologies and their Applications One day workshop within Swiss Foundation for Research and Microtechnology (FSRM) Course Series R. Wyss Digitale Signalverarbeitung FH Course HSLU T&A, Luzern Zurich Theses PhD Degrees Awarded in 2007 Name University Title C. Schuster University of Neuchatel Leakage aware digital design optimization for minimal total power consumption in nanometer CMOS technologies CSEM Employees carrying out a PhD Name Professor / University Theme / CSEM Unit Start year K. Ali P. Fua / EPF Lausanne Training embedded vision systems / Microelectronics 2007 B. Banerjee C.C. Enz / EPF Lausanne Reconfigurable baseband architecture for digital radio / Microelectronics J. Chabloz C.C. Enz / EPF Lausanne Low power receiver using RF-MEMS -analog IC design / Microelectronics M. Contaldo C.C. Enz / EPF Lausanne Low-Power MEMS based CMOS Radio Transmitter Architectures / Microelectronics 2007 2003 2006 L. Davoine H.-P. Herzig / University of Neuchatel Organic Coupled Subwavelength Devices / Photonics 2007 M H. El Mechat H.-A. Loeliger / ETH Zurich Examination of modern modulation schemes for future 3D-TOF cameras / Photonics M. Fretz H.-P. Herzig / University of Neuchatel Flip-chip bond technologies for System-in-Packages / Microrobotics 2006 2005 S. Graf A. Stemmer / ETH Zurich Automated cell injection system / Microrobotics 2007 M. Guillaumée B. Deveaud-Plédrand / EPF Lausanne Surface plasmons / Nanotechnology & Life Sciences 2006 B. Kheradman C. Piguet / CSEM Y. Leblebici / EPFL Process variations and leakage current in digital circuits / Microelectronics 2007 M. Klein J. Brugger / EPF Lausanne Polymer templated nanopatterning for MEMS applications / Nanotechnology & Life Sciences R. Lockhart P. Renaud / EPF Lausanne MEMS programmable diffraction gratings / Nanotechnology & Life Sciences 2007 2006 V. Longchamp F. Mondada / EPF Lausanne A. Martinoli / EPF Lausanne Planatary visual exploration with a team of mobil robots / Microrobotics 2006 A.-M. Popa J.A. Hubbell / EPF Lausanne Design, characterization and applications of stimuli responsive surfaces based on macromolecules / Nanotechnology & Life Sciences J. Nüesch P. Seitz / University of Neuchatel Element-sensitive X-ray microscopy and micro- Computer-Tomography / Nanomedicine 2005 2007 129

Name Professor / University Theme / CSEM Unit Start year J. Przybylska P. Renaud / EPF Lausanne Nanodispensing of liquids in attoliter scale using probe arrays / Nanotechnology & Life Sciences M. Ramuz P. Seitz / University of Neuchatel High-efficiency photodetectors with organic semiconductors / Photonics F. N. Reale M. Vetterli / EPF Lausanne Voice restoration system for laryngectomees / Systems Engineering J. Rousselot J.-D. Decotignie / EPF Lausanne Energy Efficient Routing for Wireless Sensor Networks / Systems Engineering A. Schifferle E. Mazza / ETH Zurich Fracture behavior of single crystal structures / Microtechnology and MEMS O. Schleusing J.-M. Vesin / EPF Lausanne Voice restoration of distorted speech due to laryngectomy / Systems Engineering J. Solà I Caros R. Müller / ETH Zurich Continuous non-invasive blood pressure estimation / Systems Engineering J. Taprogge B. Nelson / ETH Zurich High speed CAD model tracking for microassembly tasks / Microrobotics L. Wang P. Hoffmann / EPF Lausanne Nanopatterning by block copolymer lithography / Nanotechnology & Life Sciences G. Weder J. Vörös / ETH Zurich Interaction of cells with nano-patterned surfaces / Nanotechnology & Life Sciences H. Zhan J.-Y. Le Boudec / EPF Lausanne Impulse Radio Ultra-Wideband Channel Estimation and Location Technology / Systems Engineering 2007 2006 2006 2005 2006 2007 2004 2006 2007 2006 2007 Commissions and Committees N. Blanc Board member, Swiss Society for Sensor Technology C. Bosshard Advisory Board of Advanced Functional Materials Board member of the SwissLaser Net A. Dommann Board ESM Board member, Swiss Vacuum Society Committee member CCMX: ERU: Particle and coatings (SPERU) Excom member NanoTera Member of CTI-MNT group Member of technical committee of ENIAC Member of the expert team of BMFIT, Vienna Member of the selection board ESA, Noordwijk Member of the steering board of EUCEMAN President of Swiss MNT Network C. C. Enz Member of the Technical Program Committee of the International Solid-State Circuits Conference (ISSCC 2007), San Fransisco, USA Technical Program Committee, European Solid-State Circuits Conference (ESSCIRC 2007), Paper Selection Meeting, Meeting of the ESSCIRC-ESSDERC Steering Committee, Munich, DE, 2007 130

J. R. Farserotu Member of the Editorial Board of Wireless Personal Communications An International Journal, Springer Vice-Chair and Research Co-ordinator, Hermes Partnership, a network of leading organizations in wireless and mobile communication in Europe Vice-Chair, European Telecommunication Standards Institute (ETSI), ETSI Project ehealth (EP ehealth) H. Heinzelmann Evaluator for ERC Starting Grants Expert for Austrian Nano initiative International Advisory Board, Nanomedicine WIRE International Scientific Committee Smart System Integration, Paris, France Member of German Physical Society (DPG) Member of SPG PhD Committee, V. Spassov Program Committee MNE 2007, Copenhaguen, Denmark Program Committee SPP3, Dijon, France Science Advisory Board, Nanodimension Secretary Nanotechnology, Swiss Society for Optics and Microscopy T. Hinderling Member of Steering Committee Nano-tera Member of Steering Committee of CCMX Member of Steering Committee of NCCR Quantum Photonics G. Kotrotsios Member of Organizing Committee, Industrial Liaison, SSBE Annual Meeting 2007, Neuchatel, Switzerland Member of Scientific Committee 4th Phealth Conference, Porto Carras, Chalkidiki, Greece Member of the International Committee, 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society in conjunction with the Biennial Conference of the French Society of Biological and Medical Engineering, August 2007, Lyon, France A. Perret ANR, Agence Nationale pour la recherche (FR), Project reviewer ASRH Scientific Board BioAlps Board Conseiller personnel du chef de la division Recherche et Technologie du CEA (FR) EpoSS Communalities Group Euripides Scientific Adviser of the Board, Council Member and Adviser of the Council Groupe d experts : vision stratégique de la nouvelle école issue de la fusion de l'ecole d'ingénieurs de Genève et de l'ecole d'ingénieurs de Lullier Heterogeneous Technology Alliance, Steering Committee Coordinator Holst Center Eindhoven, Advisory Board Member Président du Comité scientifique et technologique de la Fondation Franco-Suisse pour la Recherche et la Technologie (FFSRT) Program Committee of Smart System Integration Conference Secrétaire de la Fondation du prix Omega 131

C. Piguet Member of the Board of the Strategic Research Foundation of Sweden (SSF). STRINGENT Project, Linköping University Membre de l Editorial Board of Microelectronics Journal, Elsevier Membre du comité de rédaction du bulletin de la Société Suisse de Chronométrie Membre du Conseil d Administration de Centredoc, Neuchatel Program Committee and Special Session Organizer at ICECS 2007, ICECS 07 Program Committee of DASIP 2007 MINATEC Program Committee of ESSCIRC 2007 Special Sessions Chair DATE 2007, Nice Steering and Program Committee of FTFC 07 Steering and Program Committee of Low-Power Symposium ISLPED 07 Steering and Program Committee PATMOS'07 Steering Committee of the ALaRI Master Course, University of Lugano P. Seitz Chairman of the board of Dynetix AG, CH-Landquart Chairman of the board of Heliotis AG, CH-Root Delegate of the EOS board for European Affairs, D-Hannover Editor-in-Chief, Sensors Scientific Journal Expert and Rapporteur, FP7 Photonics hearings and shortlisting, NoE and IP projects, November 2007 General Chair and Organizing Committee, Intl. Conference on The Grand Challenges of Photonics, D-Munich, June 2007 General Chair and Program Committee, Intl. Conference on Frontiers in Electronic Imaging, D- Munich, June 2007 Member of the board of Stakeholders in Photonics Photonics21, European Technology Platform, B-Brussels Member of the board of Espros Photonics AG, CH-Sargans Member of the board of the European Optical Society EOS, D-Hannover Member of the board of Zentronica AG, CH-Luzern Member of the Curriculum Commission Nanomedicine, University of Liechtenstein, FL-Triesen Program Committee, International Workshop on Dynamic 3D Imaging, D-Heidelberg, September 2007 R. P. Stanley Session Chair: SPIE Photonics West Jan 2007 M. Wiki CEO, Dynetix AG Prizes and Awards March 2007 First prize of the Swiss Technology Award 2007 for the CSEM Smallest Format Factory September 2007 Award Nominee for CTI Medtech Award 2007, The LEDDT - Platform (Laser Easy Drug Delivery Technology), a novel injection-free method for intraepidermal delivery of large molecular weight drugs. October 2007 Dupont Prix des Matériaux 2007 award for the outstanding work of Dr. Sivashankar Krishnamoorthy for work for his thesis carried out at CSEM. 132

Headquarters CSEM Centre Suisse d Electronique et de Microtechnique SA Rue Jaquet-Droz 1 P.O. Box CH-2002 Neuchâtel T +41 32 720 5111 F +41 32 720 5700 www.csem.ch info@csem.ch CSEM Zurich Technoparkstrasse 1 CH-8005 Zürich T +41 44 497 1411 F +41 44 497 1400 CSEM Alpnach Untere Gründlistrasse 1 CH-6055 Alpnach Dorf T +41 41 672 7511 F +41 41 672 7500 CSEM Landquart Schulstrasse 1 CH-7302 Landquart T + 41 81 330 0970 F + 41 81 330 0971