Korean scientists see (or hear) a possible energy source being wasted all around us. Noise.
Their hope is that someday your chattering voice could help charge your phone, or possibly highway walls could absorb the honking and drone of traffic to supplement the electric grid during rush hour.
Sound far-fetched? Well, at this point it pretty much is. But in their study in the journal Advanced Materials, the scientists created a piezoelectric material from zinc oxide that transforms sound waves into electricity.
Piezoelectric materials generate electricity from mechanical stress. The scientists sandwiched a bed of zinc oxide nanowires between two electrodes and exposed the device to 100 decibels. As the sound waves hit the electrode, it vibrated, causing the nanowires to compress and release. The piezoelectric nanowires generated around 50 millivolts. This is not enough to power a cell phone. And though some phone talkers seem like they are speaking at 100 decibels, humans typically converse at around 60 or 70 decibels.
Eric Bland writes for Discover:
Over the last few years, however, scientists have made dramatic advances in getting electricity out of piezoelectric devices. Most of these devices, which are not yet available for consumer purchase, would generate power as a person walks, runs or, in this case, talks. The U.S. Army is even looking at partially powering some vehicles by channeling the physical impact of a bullet into a small electrical current.
A bullet strike seems like a high price to pay for a modicum of power, but the world is a noisy place. If the technology develops, we might as well make use of all the clatter. That is, as long as it doesn't encourage people to talk even louder into their phones.
Related on SmartPlanet:
- Charge! Outfitting the military with clothing that serves as a battery pack
- Researchers investigate turning clothing into electrical chargers
- The future of cell phone charging