Battery Taps Water

A new type of battery uses the way water molecules line up when they come in contact with glass.

The electrokinetic micro-channel battery, developed by Larry Kostiuk and his colleagues at the University of Alberta, exploits water molecules having positive and negative ends. Glass takes on a positive charge wherever it touches water, explains Kostiuk. Conversely, the negative-charged ends of all the water molecules line up, faking the glass container. In the battery, water flows through glass channels, producing electricity along the channel walls.

“Each channel contributes less than a nanoamp,” says Kostiuk. “But you can gang together as many as you need.” The prototype cranks out 2 microamps.