WEARABLE ELECTRONICS

by Paul Gough
NXP, a spin-out of Philips Research

Electronics and Clothes: Wear in and Wear out

The intersection of textiles, clothes and electronics offers the possibility of radical new products. We can envisage clothes that dynamically change colour, or garments that unobtrusively monitor your physiological state, or clothes that become a second skin enhancing how you sense the world about you. But how far away are these fine visions? What can we do today and where should we head tomorrow?

Conductive fibres are the principal breakthrough that is enabling textile electronics to get off the ground. These fibres; using either silver, stainless steel or carbon in various forms enable those of an electronics disposition to start to think in terms of soft, drapable electronics; rather than the usual hard forms. Of course to a degree a conductive fibre is a wire, and wires are often not considered exciting when compared to the transistors, diodes, and a myriad of IC’s that one can normally call upon. However, that is to underestimate the ingenuity of those in this nascent field, from conductive fibres we have seen components such as:
• Fabric antennas
• Sensors that can measure stretch
• Fabric data and power busses
• Fabric electrodes for measuring heart-rate and respiration sensors

Beyond conductive fibres there are other technologies starting to have an impact in wearables, such as polymer electronics which enable soft keypads, strain-sensing and hold out the future promise of actuating fibres. As regards light and displays the options are still rudimentary but Electroluminscent wires, fibre optics, thermochromic materials and LED’s are being used, or at least experimented with. With the vast amount of research focussed on flexible displays it is likely to only be a matter of time before we see the combination of these and garments.

Of course below the surface is the rather nasty issue of garment wear and care. Although we often talk about caring for our garments what we really do is immerse them in a hot chemical bath and subsequently dry them at high temperatures. Clearly, one has to be cruel to be kind! However, such treatment is rather frightening to anyone who values the operation of his or her electrical equipment. Ensuring that textile electronics survives the cleaning process is really only just being investigated. Taking out sensitive electrical objects before cleaning is the main line of defence but sealing of electronics is also a possibility.

A toolkit of components is slowly being assembled. Quite what will be the successful applications, long term, no one really knows. Consequently, what we see happening is a great deal of experimentation, both in applications but also in mixing disciplines, which is all quite refreshing, and what makes this an interesting and pioneering area to work in. Progress is being made in the areas of sports, fashion, medical, military and workwear domains but numbers are presently small. In all likelihood it will take a number of niche applications, were wearables provides the only viable solution to see it grow. With such well defined uncertainties it is a good time to assemble a network and generate some collaborative exploration.

Paul Gough
NXP, a spin-out of Philips Research (Paul Gough was formerly manager of wearable technologies research at Philips)