Current affairs

Researchers have demonstrated a nanoscale generator that produces continuous direct current electricity by harvesting mechanical energy from environmental sources. The device could produce current from ultrasonic waves, mechanical vibration or blood flow.

Based on arrays of vertically aligned zinc oxide nanowires that move inside a novel ‘zigzag’ plate electrode, the nanogenerators could provide a new way to power nanoscale devices without batteries or other external power sources.

‘This is a major step toward a portable, adaptable and cost-effective technology for powering nanoscale devices,’ said Zhong Lin Wang, a professor of materials science at the Georgia Institute of Technology. ‘There has been a lot of interest in making nanodevices, but we have tended not to think about how to power them. Our nanogenerator allows us to harvest or recycle energy from many sources to power these devices.’

The nanogenerators take advantage of the unique coupled piezoelectric and semi conducting properties of zinc oxide nanostructures, which produce small electrical charges when they are flexed.