Self-powered devices may soon be possible

U.S. researchers say they are utilizing materials known as piezoelectrics to move science closer to self-powering devices, such as cellular telephones.

Texas A&M Professor Tahir Cagin and his team say they've made a significant discovery in the area of power harvesting -- a field that aims to develop self-powered devices that do not require replaceable power supplies, such as batteries.

Specifically, Cagin and colleagues at the University of Houston discovered a certain type of piezoelectric material can covert energy at a 100 percent increase when manufactured at a very small size -- about 21 nanometers in thickness. And when constructed bigger or smaller than 21 nanometers, they show a significant decrease in energy-converting capacity.

"When materials are brought down to the nanoscale dimension, their properties for some performance characteristics dramatically change," said Cagin. "One such example is with piezoelectric materials. We have demonstrated that when you go to a particular length scale -- between 20 and 23 nanometers -- you actually improve the energy-harvesting capacity by 100 percent.

"We're studying basic laws of nature such as physics and we're trying to apply that in terms of developing … better performing engineering materials," he added.

The research appeared recently in the journal Physical Review B.