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Imagine a future where working up a sweat not only does your body good, but it’ll also keep your favorite devices humming. That’s the goal of researchers at North Carolina State University, where Daryoosh Vashaee and his team have developed a way to harvest body heat and turn it into electricity. Although similar technologies have been around for years, NC State said that its prototypes are lightweight, flexes to the body, and generate “far more” electricity than their predecessors. “Wearable thermoelectric generators generate electricity by making use of the temperature differential between your body and the ambient air,” Vashaee, an associate professor of electrical and computer engineering, and the corresponding author of a paper on the work, explained. “Previous approaches either made use of heat sinks—which are heavy, stiff and bulky—or were able to generate only one microwatt or less of power per centimeter squared.” The NC State version, he added, generates up to 20 µW/cm² and doesn’t use a heat sink, “making it lighter and much more comfortable.” The material is very flexible and can be bent many times and still generate power. With a temperature difference of 31 °F between human skin and the surrounding air, the band can produce around 40 mW electric power. This energy could be used to power a smartwatch or other mobile devices with hopes that this type of technology could make the devices self-powered and sustainable. Eventually, the technology could even be scaled up to take advantage of other wasted heat in larger systems. “Our technology presents an easy and simple way of fabricating an extremely flexible, light, and high-performance TE generator,” explains Professor Cho. “We expect that this technology will find further applications in scale-up systems such as automobiles, factories, aircrafts, and vessels where we see abundant thermal energy being wasted.” The entire system, they said, is only 2 millimeters thick, making it suitable for incorporating into thinner garments such as T-shirts. For optimum energy-harvesting, however, Vashaee recommends a band, specifically one around the upper arm. It’s a more optimal location than, say, the wrist, where irregular contours limit the surface area of contact with the skin, or the chest, which is usually covered and has limited air flow. This wearable technology is possible due to the phenomenon known as the Seebeck effect, in which a difference of temperature between two objects induces a current through an n-type and a p-type semiconductor. N-type semiconductors have excess electrons for increased conductivity, whereas p-type semiconductors have excess positive “holes” for electrons.

INTO JAPANESE

あなたの体は、汗を流して作業だけでなく良い、ハミングお気に入りのデバイスも残しておこうとそれが未来を想像します。ノースカロライナ州立大学、ダルユシ Vashaee と彼のチームが体の熱を収穫し、電気に有効にする方法を開発した研究者の目標であります。F の周りされているが、同様の技術