Wearable Tech Converts Body Heat to Electricity
Researchers at NC State have developed a new design for harvesting body heat and converting it into electricity for use in wearable electronics. The experimental prototypes are lightweight, conform to the shape of the body and can generate far more electricity than previous lightweight heat-harvesting technologies.
Wearable thermoelectric generators, or TEGs, generate electricity by making use of the temperature differential between your body and the ambient air. 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 new technology developed at NC State generates 20 times more energy without using a heat sink, which makes it lighter and more comfortable, says electrical and computer engineer Daryoosh Vashaee.
The new design begins with a layer of thermally conductive material that rests on the skin and spreads out the heat. The conductive material is topped with a polymer layer that prevents the heat from dissipating through to the outside air. This forces the body heat to pass through a centrally located TEG that is one centimeter squared. Heat that is not converted into electricity passes through the TEG into an outer layer of thermally conductive material, which rapidly dissipates the heat. The entire system is thin—only 2 millimeters—and flexible.
“We can easily make it larger, depending on a device’s power needs,” says Vashaee, who worked on the project as part of the National Science Foundation’s ASSIST Center, with Melissa Hyland, a graduate student in civil engineering, and Haywood Hunter, an undergraduate in electrical and computer engineering.
This article was originally published by NC State News.