New carbon nanotube yarn can be stretched LED light

Put simply, you take a yarn, stretch it, it will generate electricity. Sew them into the shirt, no external power supply, the normal breathing can produce electrical signals. "Dr. Carter Haynes, director of the Nano Institute at the University of Texas at Dallas, in an interview with a Chinese-foreign cooperative study published recently in Science magazine said in an interview.

The yarn, called Twistron, is spun by many carbon nanotubes, which are about 10,000 times smaller than a human hair. In order to make the yarn highly elastic, researchers continue to increase the twist, so that it forms a spring-like structure.

"These yarns are essentially supercapacitors, but they do not need extra power to charge," said Dr. Li Na at the Nano Institute. Because of the different chemical potentials of carbon nanotubes and electrolytes, a portion of the charge is embedded in the yarn as the yarn is immersed in the electrolyte. When the yarn is stretched, the volume is reduced, the charges are brought close to each other, and the voltage generated by the charge is increased to obtain electric energy.

"The yarn produces a peak electrical power of 250 W / kg at a stretch of 30 times per second. A yarn weighs less than a fly and lightens one LED each time it is stretched." Nano Research Dr. Ray Bowman, director and author of the article, said that Twistron yarns can produce more than a hundredfold more electrical power per unit weight of Twistron yarn than other fabricable fibers.

It is worth mentioning that, salt water can also be used as electrolyte. The output of the power generating yarn can be scaled up in proportion to the increase of the yarn volume and the increase in the number of yarns working in parallel. "Twistron can eventually be used for ocean wave power generation if the production costs are reduced," Bowman said.

At present, the most suitable application of carbon nanotube yarn is for sensor or IoT communication. "With just 31 milligrams of yarn based on our average output power, IoT delivers 2 kilobytes of data every 10 seconds over a radius of 100 meters."