Generating Power Through Body Warmth

There has recently been a breakthrough at MIT and Berkley that has the potential to let us convert body warmth into useful amounts of electricity. This could be utilized in day to day life, for example, to charge mobile phones or wearable electronics.

It works by allowing heat to be harnessed by thermo-electric silicon nano-wires (shown in the picture on the right). It has been found that thermo-electric efficiency (the ability to convert heat into electricity) is enhanced if the surfaces of the device are rough. This roughness is achieved through a dense array of vertically aligned nano-wires.

Researchers at the Lawrence Berkeley National Laboratory and the University of California at Berkeley, showed high efficiency thermoelectric devices worked even at room temperature when suspended between heating pads.

While there are still issues of making the devices cost-effective, they show enormous promise in a wide range of applications. As well as wearable electronics, examples include extracting electricity from the heat generated in car exhaust pipes or as waste in electric power stations or indeed anywhere that heat is a by-product of a process.