Fancy charging your phone through your clothes?

Scientists develop high-tech yarn that can generate its own power

The days of having to carry a phone charger with you could soon be a thing of the past, thanks to a new type of yarn.

Scientists have developed a stretchy yarn called 'twistron' made of carbon nanotubes that can generate its own power.

The yarn could be used in a range of products, including smart clothing, and internet-connected devices.

"The easiest way to think of twistron harvesters is, you have a piece of yarn, you stretch it, and out comes electricity," said Carter Haines, a lead author of the study published in the journal Science.

The device, which exploits the ability of nanotubes to transfer spring-like motion into electrical energy, has numerous possible applications, according to the paper.

In the lab, tests showed that a yarn weighing less than a housefly could light up a small LED light.

When sewed into a t-shirt, it could power breathing sensors - like those used to monitor babies - using the stretch caused by the chest expanding at every inhalation.

The innovation could be used to power internet-connected devices and smart clothing, said the study's senior author Ray Baughman, a professor at The University of Texas at Dallas.

"Electronic textiles are of major commercial interest, but how are you going to power them," Dr. Baughman said in a statement.

"Harvesting electrical energy from human motion is one strategy for eliminating the need for batteries," he said.

But the twistron's most compelling feature was the ability to operate in sea water and potentially harvest vast amounts of energy from the ocean, he added.

"The grander dream is to make a real difference in the energy economy of nations," Baughman told the Thomson Reuters Foundation.

A trial in South Korea showed that a small twistron attached between a buoy and a sinker on the seabed produced electricity every time a passing wave pulled the yarn.

Baughman said that the technique could be scaled up in the future to create sea-power stations that can light entire cities, though harvesters are currently too expansive.