Whether we're talking about nanobots one day coursing through our bloodstreams or lab-on-a-chip implantable devices already in development, one of the biggest hurdles remains how to power these tiny devices. The answer may be nanogenerators.

Researchers at Georgia Tech have developed a new method of Electric power generation that could drive implantable medical devices, sensors and portable electronics without the need for bulky batteries or other energy sources. Instead of batteries, electricity for such devices would come, for instance, from muscle contraction or other body movements, according to.

The report by Zhong Lin Wang and his colleagues in the Aug. 9 issue of the ACS journal Nano Letters, describes experimental observation of electric power production with "nanogenerators" fashioned from a single zinc oxide nanowire and a nanowire belt. In earlier research, Wang's group discovered that zinc oxide nanowires produce electricity via a long-known phenomenon termed the pizoelectric effect. It occurs in certain materials, which change mechanical energy -- from flexing or twisting, for instance -- into electricity.

Potential applications include harvesting electricity from mechanical movement energy (such as body movement, muscle stretching and blood pressure), vibration energy (sound waves) and hydraulic energy (blood flow or contraction of blood vessels). The technology might be used in wireless self-powered nanodevices, to charge battery-powered devices and in building larger-scale electric power generators. (photo Nano Letters)