Mobile phones could soon be charged by power of speech

Mobile phones could soon be charged by simply speaking into the handset.
For mobile phone users, a flat battery or a lost charger are among the frustrations of modern life. Now new research promises a way to recharge phones using nothing but the power of the human voice. Electrical engineers have developed a new technique for turning sound into electricity, allowing a mobile to be powered up while its user holds a conversation.
The technology would also be able to harness background noise and even music to charge a phone while it is not in use.
However, there could be a downside to the innovation, if it gives people a new reason to shout into their phones as they attempt to squeeze in every extra bit of power they can.
Dr Sang-Woo Kim, who has been developing the design at 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. This motivated us to realise 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.”