Power-producing materials are the stuff of wearable inventors’ dreams. And scientists just created a yarn that generates electricity with a simple tug. The yarn, comprised of carbon nanotubes and submerged in an electrolyte gel, isn’t ideal for sweaters – but can harvest power from a wearer’s breathing. And there’s another surprising application: it could collect energy from ocean waves.
An international team of 29 researchers devised the the yarn material, known as twistron harvesters, “by tying a carbon nanotube string into a tangled weave of carbon and submerging it into an electrolyte gel,” according to Science Magazine. When covered in gel and tugged, the yarn can illuminate a light-emitting diode with a small current. The yarn’s peak power generation – when strands are hooked together – is 250 watts per kilogram, and Ars Technica pointed out a professional cyclist’s peak exertions are only around 10 percent of that figure.
The researchers tested the yarn by sewing it in to a shirt, and saw it generated a tiny amount of electricity as the wearer breathed in and out. The researchers also connected the yarn to an artificial muscle – a polymer that contracts when warmed, according to Ars Technica – and were able to convert fluctuations in temperature into energy. A still more unexpected way the yarn could be used is in wave power. The material operates when it’s placed in saltwater similar to the ocean, and the motion of the waves moves the yarn, allowing it to generate power. Ars Technica notes the device does need a platinum electrode as seawater can be corrosive.
The proof of concept yarn strands aren’t yet powerful enough to brighten a home, but the scientists say their technology is scalable. The journal Science published the research in late August. Scientists from institutions in South Korea, the United States, and China contributed to the study.