The reason we focus on the functionality underwater is that most electronic textiles have a structure that means they would probably cease to function when wet,” she said. “For practical use, it’s important that this textile can withstand both foul weather and wash, as this would be expected from other textiles. Our textiles can be used in a shoulder strap, but can also be produced on a larger scale and used in upholstery, mats or as filler in composite structures. The larger the textile, the more power it will produce.”
Anyone watching Swedish scientist working out on an aerobic stepper recently might have thought it a strange way to get fit. She was stepping while holding a shoulder bag, its arm strap dripping with water. In this case, exercise was secondary to science. Wasn’t attempting to bonding fabric break a sweat — rather, she was trying to simulate a brisk walk in the rain.
The idea was to test an experimental material’s response to moisture. That’s why she doused the arm strap in tap water, hoping that the special electricty-generating fabric she and her team developed not only would keep producing power when wet but would become even stronger. It succeeded on both counts.
Several groups of scientists — using different approaches — have been working to design functional alternatives to conventional batteries using fabric or yarn. “We’ve developed high-performance, wearable and stretchable yarn batteries that can be woven into smart textiles,” a materials scientist at City University of Hong Kong, whose team has produced a rechargeable battery made of yarn that is waterproof and still can function even if cut into small pieces. “It can be easily integrated… in flexible electronics, smart fabrics and smart clothes,” and maintains its power even when “bent, stretched, hit or even washed in water,” he said.
The concept of wearable electronics or electronic textiles isn’t new, but efforts to improve them with practical and innovative power sources is an ongoing quest, made all the more important now. Climate change has prompted researchers to try to devise novel clean energy sources that emphasize comfort, utility and sustainability — in particular, new options in batteries. Conventional alkaline or lithium-ion batteries typically end up in waste piles, where they risk leaking toxic materials into the soil. They also are heavy, bulky and rigid, making them cumbersome to use.
