I found this info on the web today, and thought I would share it with all of you. Harnessing electricity from body heat. Pretty interesting stuff! Heres the URL and a snipit of info about it:
Making calls from a cell phone with no battery, using just the warmth of your hand? Perhaps that’s no more than a pipe dream right now. But new circuits are already making it possible to harness body heat for generating electricity.
Numerous items of medical equipment are attached to the body of a patient in the intensive care ward. They monitor the heart rate, blood pressure, body temperature, pulse and breathing rate. This tends to produce quite a jumble of cables, for all these devices require their own electricity supply.
In future, medical sensors may be able to function without power from a wall socket. Instead, they will draw all the power they need from the warmth of the human body. The respective data will be sent by a radio signal to the central monitoring station.