Smart Textiles Update

By Dr. Kim Anderson, Writer/Reporter for [TC]²

In the late 1990's, academic institutions around the world were scrambling for grants on what they believed to be the next generation of textile research. Apparel companies were partnering with electronic companies to exploit what they hoped would be the lucrative advent of interactive textile products. The public's dependence upon mobile devices had created a need for lightweight, flexible electronic equipment. Textile structures- being strong, flexible, lightweight and able to conform to almost any shape -seemed to be ideally suited for use in revolutionary new products. The electronic industry had undergone new developments as the size of electronic components had become smaller and more powerful. If the fields of electrical engineering and textile science were merged, a whole new range of exciting opportunities could emerge. But how successful have researchers been? What challenges and hurdles have they encountered and have the hopes of offering true wearable electronics been squelched?

Conductive textiles have been successfully produced by using thin wires of various metals in woven and knit constructions. By impregnating a knit, woven or nonwoven substratum with carbon or metal powders, semi-conductive fabrics have been successfully produced (Kuhn). For the last twenty years electrically conductive and semi-conductive fabrics have been utilized in a wide variety of applications including electromagnetic interference (EMI), static dissipation and microwave attenuation among others (Smith). These types of fabrics have been designed to alleviate problems in a passive manner. By the late 1990's, it became apparent that a new genre of sophisticated textiles made from conductive fabrics could possibly be produced. The intent was to design interactive textile products with an electrically conductive network integrated into the fabric structure. The conductive network within the fabric would be designed to work in concert with the environment, soft switches and microcomputers; to be multi-functional and active; to be able to sense, respond and adjust to stimuli such as pressure, temperature, or an electrical charge (Kuhn). The new interactive fabrics were coined “smart textiles.”

Judging by the deluge of hits generated from a Google search on “smart textiles” one would assume that research has paid off. In a more thorough search, you will find your share of “The page cannot be displayed.” This aside, a select few have made remarkable strides. Using conductive yarns that are thin and flexible, penny size batteries and soft switches and sensors, some companies are making some truly remarkable products.

Phillips NV, a Dutch electronics giant, the European division of Levi Strauss & Co. and Massimo Osti, an Italian designer, were some of the first to brandish their way into the commercialized world of electronic apparel. In 2000 they introduced the apparel line - Industrial Clothing Design Plus (ICD+). The line included four jacket styles, each equipped with a microphone, remote controller, mobile phone, an earphone and a MP3 player (audio encoding and compression form featuring high quality and small size). The jackets retailed for $600 and up. Unfortunately, the electrical components had to be removed before the garment was washed, contributing to the limited commercial success. Undaunted by this first attempt, Phillips NV continues to invest in the development of wearable electronics- designing working prototypes that incorporate conductive textiles, fabric switches, fabric wiring, fabric stretch sensors, high-sensitivity fabric antennas and flexible electro-luminescent displays. Phillips has also developed apparel that features embedded GPS systems, mobile phones and digital cameras.

Gorix Ltd., a company based in England , has been in the forefront since the early 1990's, specializing in a variety of products with temperature controlled systems. The system contains a low voltage heating source that is powered by a simple circuitry and is capable of maintaining constant temperature regardless of the external ambient temperature. Recreational jackets, blankets and beds for animals are just some of the products Gorix Ltd. offers. Recently Gorix developed a heated diving suit which incorporates an advanced heating system. Previously, diving suits were heated by pumping hot water from a support vessel. The patented heating system is comprised of a series of heater pads powered by a stainless steel battery unobtrusively mounted on the diver's air cylinder.

Image Courtesy of Gorix, Ltd

Canesis Ltd. is a textile research and development company, the UK subsidiary of Canesis Network Ltd. ( formerly the Wool Research Organization of New Zealand). Canesis Ltd. has been a pioneer in the development of the SOFTswitch™, a fabric-based switch and pressure sensing technology. Stewart Collie, Science Manager of the Smart Textile Innovation Center for Canesis Ltd., was forthcoming about Canesis's research projects, highlighting some of their newest developments.

Canesis and AWI (Australian Wool Innovation) have teamed up to develop a heating system totally comprised of textile based materials. Unlike earlier heating systems that incorporate stiff, heavy wires, this system feels and drapes like a conventional textile. It is durable and washable. The heating system is currently being incorporated into socks as well as interior products such as upholstery and blankets.

Canesis Ltd. has also developed products that “light up.” A variety of products including safety apparel, novelty children's wear and textile displays incorporate electro-luminescence (EL) technology. Electro-luminescent materials are flexible and completely integrated into the products. “We're extending technology into fabrics,” Collie says. “Laying electro-luminescent components directly onto fabrics in a way that retains the flexibility of the underlying textile. That technology could be used to create wall coverings or drapes that illuminate interiors in new ways.”

Collie believes the next major breakthrough in making intelligent textiles is actuation. Actuation refers to technology that will enable textiles to move in response to stimulus — “to allow textiles to adapt their structure or properties to suit the environment..” Collie goes on to elaborate, “This might mean that the fibers can lengthen or shorten to make the fabric structure get looser or tighter…the surface of the fabric can change from water absorption to water repellent if it starts to rain!” Admittedly they're not there yet, but neither is anyone else. “That sort of thing will be available in 5 to 10 years and mainstream within 20,” he says.

Eleksen, founded in 1998, has continued to demonstrate ingenuity in the design of smart products. The company lists a heavyweight roster of personnel highly experienced in innovation, product design, textiles, electronic and software development, manufacturing and marketing. Specializing in soft sensing and switching technology, their products are durable, washable, flexible and 100% fabric . Products featured at Techtextil 2005, an international trade show catering to the latest technologies in technical textiles and nonwovens included:

•  A super thin keyboard that is “flexible and coffee-proof.” The keyboard is lightweight and can fold up to easily fit into a pocket or bag.

•  A pressure sensitive five-button switch pad that can be discreetly integrated into the sleeve of a garment. The garment is equipped with built-in headphones and an iPod (portable digital audio players designed and marketed by Apple). The buttons on the switch pad are used to control volume and simple functions such as fast forwarding the iPod.

Flexible Keyboard
Image Courtesy of Elekse

Image Courtesy of Eleksen

Some of the challenges in the development of smart textiles have been predictable associated with all new ventures. Others have been unique and rather unexpected.

A wide variety of issues need to be considered in the design and development of a product constructed using a smart textile. Successful design and development takes a panel of multidisciplinary professionals including textile scientists, polymer chemists, physicists, bioengineers , software engineers, consumer specialists and fashion designers. Finding a common meeting ground is only one of the challenges. With all the jargon associated with each field of expertise disregarding the intimidating technical terminology, it can be impossible to begin a working discourse. There is no doubt that bringing together skilled people from diverse professions, who can effectively communicate, is a hurdle that can't be dismissed.

For the textile technologist, a host of challenges arise in the weaving room. It is often necessary to cut or weld the yarns within the electrical network. Today this process is done manually, slowing down the loom's running time. Some conductive yarns are in ribbon form. It is paramount that the ribbon yarns do not twist during weaving. To avoid twisting in the weft, modifications to the yarn feeders is necessary to properly tension and guide the yarn. When used in the warp in conjunction with traditional yarns, differential yarn take-up can occur. In order to maintain consistent yarn take-up, the ribbon yarn must be fed from a separate creel or warp beam. Weaving fabrics with an electrical network veers from traditional manufacturing. Smart textiles are made in short runs - and precision and quality are of the utmost importance (Seyam).

Product development is notoriously a costly and often fruitless endeavor. In a report by Michael Kanellos of CNET News.com, Robin Shephard, CEO of Eleksen, spoke candidly about the trials and tribulations of product development.

“For the first few years, the company…chased too many opportunities,” Shephard says. In 2004 for instance, Eleksen created 109 prototypes and landed only three deals. This year the number of prototypes will be reduced to between 20 and 30.

But the high expense of research and development might just pay off for Eleksen. Sales are finally climbing. "We will do several million dollars this year as compared to the square root of zero last year," Shephard says.

The cost of smart products is an issue, but not only in the obvious ways. Currently, jackets incorporating special electronic features sell for as much as $3,000. With improved technology, developers expect to bring the retail price to less than 75% of that. Still, these are coveted unique products that make them premiere attractions for “stealing the coat right off my back,” an unfortunate reality. Attempts to conceal the electronic devices within the garment are not only an aesthetic issue, but a safety concern as well.

For products that are stationary, a power source does not present a problem. However, in a portable application such as a garment, some type of mobile power source is required. Stewart Collie of Canesis, says, “The size and weight of the power source required is a challenge for us, especially in portable applications. We are using conventional and rechargeable batteries, but also keeping an eye on any new developments in the field.”

Some scientists are having success using light as the power source. Scientists in Germany have developed synthetic fibers that generate electricity when exposed to light. The researchers say the fibers could be woven into machine-washable clothes to make the ultimate in portable solar cells. The discovery may provide a big boost for developers of wearable computers. The only downside to this invention is that the power source is rendered dysfunctional in the dark

Regardless of the challenges, there are some exciting opportunities in the field of smart fabrics. As emphasized at TechTextil 2005 in May, the vast majority of commercially available products specialize in pressure-sensitive keypads and heating systems. No doubt, as the electronics and textile industries continue to make advancements, new innovative products which can respond and adjust to external stimuli will emerge.

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