Power your mp3 with your heart beat

In a few years, you may never have to recharge your phone again. Today scientists announced the first viable "nanogenerator," a tiny computer chip that gets its power from body movements like snapping fingers or - eventually - your heartbeat.
This technology, long anticipated by futurists, could replace batteries for small devices like MP3 players and mobile phones within a few years. For now, they can generate enough electricity to power a liquid crystal display and an LED. A group of researchers led by Georgia Tech's Zhong Lin Wang announced their groundbreaking discovery today at a meeting of the American Chemical Society in California. So how do these nanogenerators work, and when can you buy one?<!--more-->
The generator itself is a flexible computer chip that you squeeze between your fingers. The chip converts the pressure into electrical energy, which it can store in capacitors and use to power LEDs. Over the past six years, Wang and his colleagues have boosted its power output by thousands times and its voltage by 150 times - and they think this is just the beginning.