Voice power could drive self-charging phones

It all sounds a bit perpetual-motiony at first, but a researcher at Texas A&M University says he might have discovered the key to creating mobile phones and other devices that never need charging.

The secret seems to be a piezoelectric material that can generate an electrical charge from sound waves … in other words, the user’s own voice. Not just any piezoelectric material will do, though: the university research team found the perfect material must have a thickness of just 21 nanometers, no more, no less.

“When materials are brought down to the nanoscale dimension, their properties for some performance characteristics dramatically change,” said lead researcher Tahir 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.”

If a way can be found to make such piezoelectrics commercially viable, mobile phone users wouldn’t be the only ones to stop worrying about batteries and recharging devices. The technology could also benefit a wide range of computer users, including the military.

“Even the disturbances in the form of sound waves such as pressure waves in gases, liquids and solids may be harvested for powering nano- and micro devices of the future if these materials are processed and manufactured appropriately for this purpose,” Cagin said.

The important word here, of course, is if. But imagine the future if if becomes when.