A report from the British paper the Telegraph profiles a new technology under development in Seoul that harnesses the power of sound to charge mobile phones, using background noise, music and the human voice to juice up the battery.
A sound-absorbing pad between two electrodes vibrates when hit by sound waves. That pad then compresses and releases two zinc oxide wires to generate an electrical current.
The scientists are also considering applying the technology to sound-absorbing walls placed near highways, the report said.
Sang-Woo Kim of Sungkyunkwan University said the scientists have found a way to get about 50 millivolts of power out of 100 decibels of sound — about the equivalent of noisy traffic.
That’s not enough to charge a phone, but the researchers are tweaking the design to generate more power.
The report pointed out that there could be a downside to all this — if the technology takes off, folks may start yelling into their phones to pull a few more minutes out of a call.