You're not going to be using your heart as a power generator for your cellphone anytime soon, but it soon might come in handy for powering a medical implant or embedded sensor. Scientists at Georgia Tech are first trying out their Muscle-Driven In Vivo Nanogenerator idea on rats, using a minuscule nanowire to convert the motion of flexing muscles into electric current using piezoelectric energy.
The amount of power produced is too small to be useful yet, though. So the scientists will next put together arrays of these nanowires, hoping to create enough electricity to run a pacemaker. That'll solve one of the most nagging problems of electronic devices implanted in the human body: powering them up using batteries that must be changed or attached outside the body.