It"s no secret that longer battery life and safer ways to power mobile devices is what the industry is striving for. Researchers from many divisions of the Fraunhofer Institute have teamed up to devise a way to power electronic circuits by using body heat. The researchers were able to construct a method of turning body heat into electricity using the same principal as thermoelectric generators (TEG) made from semi-conductor elements. TEGs extract electricity from the temperature difference between a hot and cold environment.
Researchers from Fraunhofer say that typically a temperature difference of several tens of degrees is needed, but that the temperature difference between the body and the environment is only a few degrees. With such a small temperature difference, the TEG can deliver only 200 millivolts - most electronics require one or two volts to operate. "We combined a number of components in a completely new way to create circuits that can operate on 200 millivolts. This has enabled us to build entire electronic systems that do not require an internal battery, but draw their energy from body heat alone," said the manager of the sub-project, Peter Spies.