The generation game

A prototype electric generator working on the nanoscale has been built by researchers at Georgia Institute of Technology. The device based on arrays of vertically aligned zinc oxide nanowires that move inside a novel 'zig-zag' plate electrode produces a direct current by harvesting mechanical energy induced in the system by ultrasound energy. The designers explain that the device could just as easily draw its power from any mechanical vibration or even blood flow. "This is a major step toward a portable, adaptable and cost-effective technology for powering nanoscale devices," explains Zhong Lin Wang. Powering nanodevices has always been a stumbling block. "There has been a lot of interest in making nanodevices, but we have tended not to think about how to power them," Wang adds, "Our nanogenerator allows us to harvest or recycle energy from many sources to power these devices."