Wearable Electronics

Wearable Electronics is a term we use to describe the basic technology for integrating electronics into clothing. Electronic assistants are supposed to be always available, without getting on the user's nerves. Clothes are part of our everyday life. For this reason they are extremely well suited for the integration of such assistants.

Electronics and textiles - two worlds, which bring together. The application scope for Wearable Electronics, the integration of electronics in clothing is various. Wearable electronics can now combine seamlessly into ordinary clothing. Using various conductive textiles, data and power distribution as well as sensing circuitry can be merge directly into wash-and-wear clothing.

One might think that technology itself would drive this new wearable electronics industry, but that s a false perspective. The pull is from the fashion industry. Strong fashion brands need to continually innovate to remain fresh. In the past, they have used new high-performance textiles, but now wearable electronics is seen as a whole new avenue for differentiation.

While wearable electronics are empowering fashion accessories, clothes are still the heart of fashion, and as humans, we prefer to wear woven cloth against our bodies. The tactile and material properties of what people wear are important to them, and people are reluctant to have wires and hard plastic cases against their bodies. However people were also enthusiastic about the concept that existing electronic products could be broken up into separate yet interconnected modules and distributed over clothing, and that several applications could share a single resource such as the headphone, keyboard and display. It also demonstrated the possibility of controls made out of soft materials, such as a volume control operated by pulling a cord. Despite this, however, some found the business relevance of the activity more difficult to appreciate. In parallel with the conceptual work, research began on understanding and generating the enabling technologies that would bring the wearable electronics vision to life. Key elements for this were smart textiles, wear and care issues, and the Personal-Area Network (PAN).

Smart Textiles are the foundation for a new fashion philosophy for the 21st Century. Developed textiles for industrial, technical, medical or military purposes hold the key to the door leading to the future fashion. Bio-textiles or e-textiles uncover an enormous potential for the market of the "second skin". In the centre of all these possibilities are new materials, coatings and equipment.

Textiles that are electrically conductive but also soft and warm to touch now exist. As a result, one can relatively easily move audio, data and power around a garment. Conductive fibers can be integrated into knitwear and woven materials, and conductive inks allow electrically active patterns to be printed directly onto fabrics. One area in which active success is achieved is in generating new types of sensors based on fabric. The ability to produce material with a conductivity that changes in a predictable way as it is stretched or jackets that can sense the arm movements of the wearer. This could be used to monitor and assist people when playing sports: to analyze a forehand tennis stroke and, through feedback, help one improve it as well. It could also be used to infer from limb and body movements what a person is doing: gesturing during an animated conversation, driving or eating. This information would allow other devices to operate in a more natural way.

Though in its early stages, wearable electronics are gaining attention from garment and electronics manufacturers. What started decades ago with the pocket-sized transistor radio - probably the first popular portable electronic device - have evolved into fabrics that conduct electricity and can link audio-video equipment and pocket computers? Wearable electronics are no longer limited to comic books and geek fantasies: they are serious business. But Nike's integration of digital equipment like MP3 players into sports clothes, and the wristwatch phones created by Motorola and Swatch, is mere toys compared to what's coming.

Wearable electronics work by mixing conductive textiles, fabric switches, fabric wiring, fabric stretch sensors, high-sensitivity fabric antennas and flexible electro-luminescent displays to create a "personal area network", or PAN: an electronic network woven into the jacket connects various devices just as local area networks (LANs) connect computers. The hardware devices are clipped on or inserted where appropriate, and the PAN allows transport of data, power and control signals within a garment. Several devices can be clipped to a PAN, and a central controller with a small display alerts the wearer to incoming phone calls, e-mails - or just the title of the next song on the MP3 player. Of course the garment - minus the hardware - has to survive the washing machine and dryer.

The military camouflage outfit is replete with pathogen detectors; a high-density, low-temperature micro fuel cell that acts as a lightweight, long-life power source; and a flexible electroluminescent display. It was designed to show the functionality of embedded electronics and sensors.

The sensor technology includes pathogen detectors that are more reliable and more sensitive. For example the detectors on the military outfit could take bacteria, destroy it, then amplify the bacteria's DNA and look for certain characteristics of specific pathogens, like anthrax or small pox. Future versions could incorporate sensors to monitor a soldier's vital signs and fatigue.

The outfit also includes a flexible electroluminescent display that can be worn around the wrist to provide soldiers with instant awareness communications and updated commands, or environmental information about exposure to any biological or chemical agents. A third technology demonstrated in the outfit is an advanced micro fuel cell. The micro fuel cell would power an individual soldier's equipment for possibly up to a few weeks. It would be smaller and lighter weight than the conventional batteries that generate equivalent power

Types of Materials Used
For years the textile industry has been weaving metallic yarns into fabrics for decorative purposes. The first conductive fabric used was silk organza, which contains two types of fibers. One was a plain silk thread and the other was a silk thread wrapped in thin copper foil. This metallic yarn is prepared just like cloth-core telephone wire, and is highly conductive. The silk fiber core has a high tensile strength and can withstand high temperatures, allowing the yarn to be sewn or embroidered with industrial machinery. The spacing between these fibers also permits them to be individually addressed, so a strip of this fabric can function like a ribbon cable.

There are also conductive yarns manufactured specifically for producing fibers for the processing of fine powders. These yarns have conductive and cloth fibers interspersed throughout. Varying the ratio of the two constituent fibers leads to differences in resistivity. These fibers can be sewn to create conductive traces and resistive elements.

While some components such as resistors, capacitors, and coils can be sewn out of fabric, there is still a need to attach other components to the fabric. Soldering directly onto the metallic yarn can do this. Surface mount LEDs, crystals, piezo transducers, and other surface mount components with pads spaced more than 0.100 inch apart are easy to solder into the fabric. Once components are attached, their connections to the metallic yarn may need to be mechanically strengthened. This can be achieved with an acrylic or other exible coating. Components with ordinary leads can be sewn directly into circuits on fabric, and specially shaped feet could be developed to facilitate this process.

Gripper snaps make excellent connectors between the fabric and electronics. Since the snap pierces the yarn it creates a surprisingly robust electrical contact. It also provides a good surface to solder to. In this way subsystems can be easily snapped into clothing or removed for washing.

Innovation is a key factor to operating successfully in any market. Within the textile industry, the challenge for companies today lies in bringing to market a stream of new and improved, value-added products, in order to strengthen existing product lines, and diversify into new areas. Technology represents one critical route in doing so.

Recent advances in high added-value textiles which incorporate electronics, smart systems, are responsive or highly-functional; create opportunities to deliver new markets and improvements, to the textile industry. These developments are achievable via advances in science and technology, and collaborations between people from a variety of backgrounds and disciplines.

This bracelet was developed to investigate the introduction of wearable computing applications in financial transactions, and in particular for use with ATM machines. The bracelet is able to store, share and collect information. At the same time it can be worn as a fashion accessory. The bracelet enables users to customize the information they want to carry with them at any given time. Using this one can connect to a home computer for viewing or storing information and for accessing the internet, connect to a prototype ATM machine, instead of an ATM card, connect to point of sale stations and function as a key to different access points (the house, work environment, gym pass)

An outfit that communicates, via wristbands, to the solar panels in a surfer s body suit to adjust the suit s temperature. New combinations of fiber, fabric and micro-circuitry are also turning up in prototypes for competitive sports, combat wear and extreme sports. For example, future skiers will have GPS navigation, electronic ski passes and radio communications built into their clothing. Integrated fabric sensors are being manipulated to display and monitor everything from body temperature to pulse and blood stats. Trends suggest that soft fabric sensors could eventually cover the entire body and monitor an athlete s form, motion, and health.

The military and medical fields are also creating wearable electronics. The Department of Defense is experimenting with exoskeletons (or battlefield armor) that are smart, strong, and lethal to help soldiers communicate effectively, move quickly, lift large weaponry and leap to non-human heights and distances. This human performance augmentation promises to take war to superhero-like levels. A byproduct of this combat technology is the Smart Shirt, the world s first wearable motherboard that incorporates two-way sensing, monitoring and information processing technology into the fabric. It has all sorts of application in medicine for monitoring and communicating patient health.

User tests in different parts of the world have indicated that this fashion/technology mix could be a highly desirable combination. In the future, clothes will be an important part of the user s personal electronic network. This technology will allow the network to hear what the user hears and to see what the user sees. It will be a companion for long periods of time, natural in its interactions and proactive in its support. The interface will move from a personal one to an intimate one.