Published on the 15/06/2011 | Written by Newsdesk
New technology that turns sound waves into electricity is being used to develop mobile phones that charge themselves using the sound of the human voice…
Researchers at the University of Korea are using the technique to create devices that charge themselves gradually, using ambient sound when the phone is not being used, and then receive a larger boost when the phone is in operation by using the energy of the spoken word.
The technology uses tiny strands of zinc oxide positioned between two electrodes. A sound absorbing pad on top vibrates when sound waves hit it, causing the tiny zinc oxide wires to compress and release. This movement generates an electrical current that is used to charge a battery.
One of the developers of the project, Dr Sang-Woo Kim, of the institute of nanotechnology at Sungkyunkwan University in Seoul, South Korea, said: “A number of approaches for scavenging energy from environments have been intensively explored.
“The sound that always exists in our everyday life and environments has been overlooked as a source [of energy]. This motivated us to realize power generation by turning sound energy from speech, music or noise into electrical power.
“Sound power can be used for various novel applications including cellular phones that can be charged during conversations and sound-insulating walls near highways that generate electricity from the sound of passing vehicles.
“The latter development would have the additional benefit of reducing noise levels near highways by absorbing the sound energy of vehicles.”
