You wouldn't immediately think of the ear's cochlea as an energy source, but MIT knows that every mammal effectively has a pair of very small power plants because of the ionized environment. School researchers are trying to harness that energy through a new sensor that exploits the whole ear canal system. As eardrum vibrations naturally create a usable voltage from brain signals, the prototype can build enough charge in a capacitor to drive a very low-power wireless transmitter that relays the electrochemical properties of the ear a