A generator that converts ambient movement - including gentle wind, water tap flow and normal body movement - to electric power is reported in Nature Communications this week. The device, called a rotary triboelectric generator, is efficient and low cost.
Triboelectric generators function on a similar principle to the well-known demonstration of charge transfer: rubbing a balloon against clothing builds up negative charge on the surface, which can flow into a wall, causing the balloon to stick. Zhong Lin Wang and colleagues report a new triboelectric generator design that harvests this charge build-up and transfer, in a robust and cost effective rotary design. Specifically, charge generated by the rotation of surfaces with differing charge affinities is transferred away as useful power by a stationary array of gold electrodes. They report 24% efficiency and can run it off a range of ambient movements, demonstrating the capability of the device for use renewable energy generation.
The simplicity of the device design and its low cost could make energy harvesting from renewable sources, or even every day body movements, a real option.