MEMS device generates power from body heat

In an attempt to develop a power source that is compact, environmentally friendly, and has an unlimited lifetime, a team of researchers from Singapore has fabricated an energy harvesting device that generates electricity from body heat or any environment where there is a temperature gradient. Their device, called a thermoelectric power generator, attaches to the body and generates a power output of a few microwatts, which could be useful for powering implanted medical devices and wireless sensors.
The entire generator consists of a chip with a size of 1 x 1 cm2, which holds more than 30,000 thermocouples. The thermocouples, when arranged in groups called thermopiles, detect a temperature difference between the hot and cold junctions and produce a voltage. With a temperature difference of 5K, the device can generate a voltage of 16.7 volts and a power output of 1.3 microwatts. For more info ...