New Technologies In E-Textiles

Car seats that wake up drowsy drivers, bed sheets that monitor your health, socks that let you know when you are about to do a tendon, vests that trigger an emergency beacon if you are dying of exposure - these are all concepts that may not be as far away as you think and were recently discussed at the Electronic textile Workshop held in Geelong.

Textile scientists, polymer chemists, physicists, and bioengineers from around the world met at CSIRO Textile and Fibre Technology not only to dream about the garments and textiles of the future, but also to talk about the technologies that will turn these dreams into reality. CSIRO hopes the meeting will lead to international collaborations.

The workshop explored ways in which the new technologies might be applied. Some of the ideas raised included:

• Smart materials with improved functionality including the ability to sense and react to external conditions (temperature and humidity), communications, light emission and shielding the wearer from radiation.

• Garments that sense temperature and respond by generating heat or contracting to change their warmth or moisture management characteristics.

• Electronic fabrics that protect against hazards posed by low-level electromagnetic radiation.

• Electronic textiles that have potential for reducing noise generated by moving parts.

• Garments that are softer, lighter thinner and more vapour permeable than conventional products providing better protection systems.

• Body suits that monitor your physiological state and communicate to your doctor.

Interactive Electronic Textile Technologies

Electronic textiles can be created by using minute electrically conductive fibers. These metallic fibers have been used for years in various industrial applications for the purpose of controlling static and electromagnetic interference shielding. Today, metallic fibers are finding new applications in the development of electronic textiles. Electrically conductive fibers can be classified into two general categories, those that are naturally conductive and those that are specially treated to create conductivity.

Naturally conductive fibers or metallic fibers are developed from electrically conductive metals such as ferrous alloys, nickel, stainless steel, titanium, aluminum, copper, and carbon. Metal fibers are very thin metal filaments, with diameters ranging from 1 to 80 microns (µm). Officially called a micrometer, a micron (µm) is one thousandth of a millimeter. To illustrate the fineness of a metallic fiber of 1 µm, a comparison can be made between these fibers and the diameter of a strand of human hair which ranges between 70 and 100 µm.

Metallic fibers are typically produced by either using a bundle-drawing process or by a shaving process. The bundle-drawing process consists of bundling several fine metal wires then drawing them continuously and simultaneously from source metals.

History of Wearable Computing

Wearable computing devices have been around for years. They can easily be defined as devices that become part of the users personal space and are operationally and interactively controlled by the user, i.e. they are always on and accessible .

Historical research suggests the first complete wearable computer, conceived in 1955, was designed to predict outcomes of the casino gambling game roulette. This wearable system was a cigarette-pack sized analog computer with four push buttons. A data taker would use the buttons to indicate the speed of the roulette wheel, then the computer would send tones via radio to a hearing aid worn by the bettor. This wearable was later prototyped in 1961 by Edward Thorp and Claude Shannon at the Massachusetts Institute of Technology. Thorp disclosed a similar system, featured in the March 27th 1964 issue of Life Magazine, for beating the Wheel of Fortune gambling game.

Since then, many researchers have experimented with wearable concepts. One such researcher, Steve Mann, professor at the Massachusetts Institute of Technology (MIT), is considered a pioneer in the area of wearable computing. He has been designing and building wearable devices since the early 1980's. Early wearable computing systems developed by Mann consisted of head and waist mounted displays and cameras.

These apparatus have proved to be cubersome and awkward, therefore they are impractical for daily use. Today, Mann's wearables have shifted toward more comfortable and practical devices such as eyeglass based communication systems, 'smart shoes' that incorporate sensors to provide information on footstep force and velocity, and 'smart undergarments' that can monitor heart rate and respiration.

Overview of Electronic Textiles

Electronic Textiles (e-textiles) are fabrics that have electronics and interconnections woven into them, with physical flexibility and size that cannot be achieved with existing electronic manufacturing techniques. Components and interconnections are intrinsic to the fabric and thus are less visible and not susceptible to becoming tangled together or snagged by the surroundings. An e-textile can be worn in everyday situations where currently available wearable computers would hinder the user. E-textiles can also more easily adapt to changes in the computational and sensing requirements of an application, a useful feature for power management and context awareness.

E - Textiles have applications ranging from smart materials for aerospace applications to wearable computing. This paper addresses the modeling of computation, communication and failure in e-textiles and investigates the performance of two techniques, code migration and remote execution, for adapting applications executing over the hardware substrate, to failures in both devices and interconnection links. The investigation is carried out using a cycle-accurate simulation environment developed to model computation, power consumption, and node/link failures for large numbers of computing elements in configurable network topologies. A detailed analysis of the two techniques for adapting applications to the error prone substrate is presented, as well as a study of the effects of parameters, such as failure rates, communication speeds, and topologies, on the efficacy of the techniques and the performance of the system as a whole. It is shown that code migration and remote execution provide feasible methods for adapting applications to take advantage of redundancy in the presence of failures and involve trade offs in communication versus memory requirements in processing elements.