FIBER OPTICS IN TEXTILE Rsch. Assist. Kami Emirhan Yeditepe University, Faculty of Fine Arts, Department of Fashion and Textile Design, Turkey kamiemirhan@yeditepe.edu.tr 1.Fiber Optics Fiber optics are long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over long distances. Multi-mode fibers have larger cores (about 2.5 x 10-3 inches or 62.5 microns in diameter) and transmit infrared light (wavelength = 850 to 1,300 nm) from light-emitting diodes (LEDs). Some optical fibers can be made from plastic. These fibers have a large core (0.04 inches or 1 mm diameter) and transmit visible red light (wavelength = 650 nm) from LEDs. 1.1.The Relationship between Light and Fiber Optics Suppose you want to shine a flashlight beam down a long, straight hallway. Just point the beam straight down the hallway and light travels in straight lines, so it is no problem. If the hallway has a bend in it, you can place a mirror at the bend to reflect the light beam around the corner. And if the hallway is very winding with multiple bends you may line the walls with mirrors and angle the beam so that it bounces from side-to-side all along the hallway. This is exactly what happens in an optical fiber. Scheme 1 Parts of a single optical fiber - Core - Thin glass center of the fiber where the light travels - Cladding - Outer optical material surrounding the core that reflects the light back into the core - Buffer coating - Plastic coating that protects the fiber from damage and moisture There are two types of optical fibers: - Single-mode fibers - Multi-mode fibers Single-mode fibers have small cores (about 3.5 x 10-4 inches or 9 microns in diameter) and transmit infrared laser light (wavelength = 1,300 to 1,550 nanometers). Scheme 2 total internal reflection in an optical fiber The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection (Scheme 2). Because the cladding does not absorb any light from the core, the light wave can travel great distances. However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light.
1.2. A Fiber-Optic Relay System To understand how optical fibers are used in communication systems, let's look at an example from World War II. Suppose that two naval ships in a fleet need to communicate with each other while maintaining radio silence. One ship pulls up alongside the other. The captain of one ship sends a message to a sailor on deck. The sailor translates the message into Morse code and uses a signal light to send the message to the other ship. A sailor on the deck of the other ship sees the Morse code message, decodes it into English and sends the message up to the captain. Now, imagine doing this when the ships are on either side of the ocean separated by thousands of miles and you have a fiber-optic communication system in place between the two ships. Fiber-optic relay systems consist of the following: - Transmitter - Produces and encodes the light signals - Optical fiber - Conducts the light signals over a distance - Optical regenerator - May be necessary to boost the light signal (for long distances) - Optical receiver - Receives and decodes the light signals to the other user's computer, TV or telephone (receiving ship's captain). The receiver uses a photocell or photodiode to detect the light. 2. Fiber Optics In Textile 2.1. Smart Shirt In October 1996, A project called Georgia Tech Wearable Motherboard (Smart Shirt) was initially funded by the U.S. Navy and in 2000, The Georgia Tech Research Corporation licensed the technology to New York-based SensaTex Inc. to manufacture and market the Smart Shirt. Dr. Sundaresan Jayaraman, who is a professor at the School of Textile & Fiber Engineering Georgia Institute of Technology, is also the principal investigator at this project. According to Jayaraman, Smart Shirt is a computer t- shirt woven with fiber optics and electrically conductive thread that can monitor the health of soldiers, rescuers, the elderly and others who are medically vulnerable. The main advantage of Smart Shirt is that it provides a very systematic way of monitoring the vital signs of humans in an undisturbing manner. To use this new technology; first sensors are attached to the body, then the shirt is pulled on and sensors are attached to the shirt. Transmitter The transmitter is like the sailor on the deck of the sending ship. It receives and directs the optical device to turn the light "on" and "off" in the correct sequence, thereby generating a light signal. Optical Regenerator Some signal loss occurs when the light is transmitted through the fiber, especially over long distances (more than a half mile, or about 1 km) such as with undersea cables. Therefore, one or more optical regenerators are spliced along the cable to boost the degraded light signals. Optical Receiver The optical receiver is like the sailor on the deck of the receiving ship. It takes the incoming digital light signals, decodes them and sends the electrical signal Figure 1 The fabric being woven Figure 2 Prof. Dr. Sundaresan Jayaraman wearing the Smart Shirt
Figure 2 shows that Smart Shirt is armed and ready to detect what is going on in a soldier s body at a battlefield. Shirt itself is so customizable that sensors to detect any required information, such as; bullet wounds, temperature, heart rate and respiration rate, oxygen levels or hazardous gas levels (which indicates that Smart Shirt can also be used by fire department or police department) can be added if necessary. This flexible data bus integrated into the structure, transmits the signals to the army headquarters or in civilian case to the fire station or to the police station giving information about the health status of the person who wears it. Georgia Tech Wearable Motherboard can also be used on patients that are continuously need to be monitored (e.g., patients discharged after major surgeries, patients those are suffering from manic depression) and this reveals the possibility of telemedicine. Likewise, continuous monitoring of astronauts in space, of athletes during practice sessions and in competition are all extremely important. Smart Shirt, which can be laundered without any damage to the sensors themselves, is no doubt one of the 21st century s best inventions and in 2002 it took its place among the Smithsonian Institution s collection of important items in the history of textile in Washington, D.C. 2.2. Flexible Screen France Telecom R&D, announced in the press release May 03, 2002 that, it has designed a prototype for a flexible screen made of woven optical fibers capable of downloading and displaying static or animated graphics such as; logos, texts, patterns, scanned images etc. By this innovation we understand that, clothes can now act as a graphical communication interface, displaying visual information in real time and offering access to all telecom services (internet, video, e-commerce and 3G mobiles). on luminous diodes. A special abrasion process for the fibers at the surface of the fabric associated to a specific fabric weave developed by the France Telecom laboratories made it possible to create the first bitmap screen matrix on a flexible textile base. Figure 3 Clothing with a flexible fiber-optics screen and remote-control Figure 4 Backpack with a flexible fiber-optics screen and remote-control This unique display technology is based on the association of fabric containing optical fibers and an electronic control system that controls lighting based Figure 5 Flexible Screen on a scarf Figure 6 Flexible Screen on clothing
The fabric functions like a screen on which all sorts of visual information can be downloaded through a wireless link (by using radio waves or Bluetooth Technology) via the internet from an office computer or a mobile, or even a dedicated internet site. A flexible remote-control in the garment makes it possible to call up the visuals stored in the clothing s memory and to generate several related special effects. 2.3. Luminex After numerous attempts and experiments, it has finally been possible to integrate a luminous fibre into a fabric, giving its own brilliance. Luminex is a new fabric that can emit its own light. It s the result of a close collaboration between a highly technological electronics company like CAEN spa, which is in fact the world s leading company in the planning and production of electronic equipment for use in Nuclear physics experiments, and two companies operating in textiles sector FIT spa in Prato and the Swiss company STABIO sa. In Luminex, together with optic bright and/or sparkling fibers, natural and synthetic fibers can be used. Natural and/or synthetic fibers may be of any color. Fibers transmitting light are uncolored, they take the color of the bright source which is connected to them. Luminex can be supplied directly by 200/110 Volt using a smaller transformer (i.e.: loading for mobile phone batteries) or by a mini-battery which can be re-loaded. Figure 7 Flexible Screen on backpack Previewed at Avantex 2002, the international trade show for garment textile innovation, this prototype of a flexible screen, was awarded the prize for Research and Development Innovation and definitely it will be one of the most important usage patterns for the advertising industry. Figure 9 A closer look at Luminex Figure 8 A closer look at the Flexible Screen The first application is easily suitable for curtains, panels, and fixed structures, while the second for wearing clothes or for all mobile things. The battery is inserted in the more practical available housing, according to the manufacturing. For example, into a pair of jeans the housing is usually a small pocket on the right side of the trouser.
Figure 12 LUMINEX used to cover chair Figure 10 Bag made of Luminex by United Colors of Benetton Luminex has already manufactured and displayed several items to be sold on its internet site. Among them are, cushions, bras, shirts, bags etc. Figure 13 LUMINEX on several decorative and functional objects Figure 11 LUMINEX used as a tablecloth In Figure 11, 12, 13, it is clearly visible that LUMINEX will play a major role in the interior decoration sector. Figure 14 A closer look at Luminex
3. Summary Textile has always been one of the indispensables of our lives. The concept of design was always there. Then technology was invovled and eventually came the mass producton. With the inclusion of synthetic raw materilas to the textile world, vision of design expanded beyond dreams and now Fiber Optics are intruduced to us. Bibliography Schemes 1,2 Fig. 1,2 Fig. 3,4,5,6,7,8 Fig. 9,10,11,12,13,14 www.howstuffworks.com www.gtwm.gatech.edu www.francetelecom.fr www.luminex.it With Fiber Optics, engineers and designers have come up with quite creative ideas of modifying our daily lives by integrating it into a woven fabric. It s doubtlessly fascinating that, usage of this facility revealed the possibility of telemedicine, which suggests; monitoring and treatment of humans those in post-operative recovery, geriatric patients, mentally ill patients, children susceptible to sudden infant death syndrome and individuals prone to allergic reactions, and these are just a few forseen examples. Army, Police Departments and Fire Departmens will also be capable of monitoring their staff during a healthcare situation. Another major concequence of this new invention is of course its commercial side. Wouldn t it be great if you possessed an armchair that glows at night and you could change its color within seconds, or a table cloth, a cushion, a curtain, a panel, a rug or even an umbrella with the same qualifications? Maybe you would like to wear garments or use a backpack of that kind on which you can display constantly changing colors and images. And these, brings to mind the fact that, advertisement and entertainment sectors will also be one of the most to benefit from this innovation. In conclusion, as long as the interactivity between design, technology and manufactuirng develops gradually by the desire to design, which is the major fact that pushes technology onwards, we can be sure that such breakthroughs will not only expedite our lives but also play a vital role on our existence.