Nano coating for heated clothing

Commuters, skiers, crossing guards and others who endure frozen fingers in cold weather may look forward to future relief as manufacturers are poised to take advantage of a new technique for creating electrically heated cloth developed by researchers at the University of Massachusetts Amherst. They have made gloves that keep fingers as warm as the palm of the hand.

Three-layered demonstration glove

The demonstration glove the scientists made can keep fingers toasty for up to eight hours. The three-layered glove, with one layer coated by the conducting polymer poly(3,4-ethylenedioxytiophene), also known as PEDOT, are powered by a button battery weighing 1.8 grams. A dime weighs just under 2.27 grams. The authors point out, “Lightweight, breathable and body-conformable electrical heaters have the potential to change traditional approaches to personal thermal management, medical heat therapy, joint pain relief and athletic rehabilitation.”

Coating works even in water

Trisha Andrew says, “We took a pair of cotton gloves and coated the fingers to allow a small amount of current to pass through, so they heat up. It's regular old-fashioned cotton cloth. We chose to make a pair of gloves because the fingers require a high curvature that allows us to show that our material is really flexible. The glove is powered by a small coin battery and they run on nano-amps of current, not enough to pass current through your skin or to hurt you. Our coating works even when it's completely dunked in water, it will not shock you, and our layered construction means the conductive cloth does not come into contact with your skin.”

Ready for market in five years

She adds, “We hope to have this reach consumers as a real product in the next few years. Maybe it will be two years to a prototype, and five years to the consumer. I think this is the most consumer-ready device we have. It's ready to take to the next phase.” Until recently, textile scientists have not used vapour deposition because of technical difficulties and high cost of scaling up from the laboratory. But recently, manufacturers are finding that the technology can be scaled up while remaining cost-effective, the researchers say. Using the vapour deposition method, the team also coated threads of a thick cotton yarn commonly used for sweaters. It performed well and offers another avenue for creating heated clothing, they state.

Easy to repair with plain thread

The materials scientists conducted several tests to assure that their gloves could stand up to hours of use, laundering, rips, repairs and overnight charging. Andrew notes, “Right now we use an off-the-shelf battery that lasts for eight hours, but you would need a rechargeable to make these more practical.” Further, “If you are skiing and rip your glove, you can repair it just by sewing it back together with plain thread.”