By Peter Weiss
A new way to use flowing water to generate electricity may lead to gadget-size, hydroelectric batteries. So say engineers at the University of Alberta in Edmonton, who have powered a tiny lamp by driving water through channels only about twice the diameter of a red blood cell.
The new approach to electric power uses no moving parts, such as in turbines. Instead, the rush of water on a miniature scale drags positive ions downstream, creating a usable voltage difference. The prototypes built so far can power only tiny devices, such as the light-emitting diodes used as on-off indicators in electronic devices. Only about 1 percent of the mechanical energy supplied to move the water gets converted to electricity, says Alberta mechanical engineer Daniel Y. Kwok.