Nanowire generators could one day lead to medical devices powered by the patient's own heart. A tiny, nearly invisible nanowire can convert the energy of pulsing, flexing muscles inside a rat's body into electric current, researchers at Georgia Institute of Technology have shown. Zhong Lin Wang and his research group attached special designed nano wires to a rats diaphragm and heart. When the rat breathes and its heart beats they could respective generate about four pico-amps of current at two millivolts and 30 pico-amps at about three millivolts. Although this amount of current is extremely low (a pico-amp is a million millionth of an amp), it holds many promises for powering nano sized devices. Wang’s team is now looking at combining multiple nano wires to harvest more energy. The nano wire is made of zinc oxide and placed on a flexible polymer. By encapsulating it with another polymer the nano wire is protected from bodily fluids. The wires generate energy under mechanical stress, which is called the piezoelectric effect. Wang’s team has now proven this could effect could also work inside the body of a living being. Perhaps someday we could charge our mobile by our own heart power? Full paper: Advanced Materials, via: Techreview.