While at my local gym recently, I happened to mention to my personal trainer that they should find a way to hook the treadmills, bicycles, and elliptical machines up to the power grid and use the exertions of the gym’s own customers to power the building (at least in part). (He just looked at me blankly and then increased the severity of my workout. I get that a lot.)
Anyway, I still like the idea of using normal everyday activities and even human movements to generate power, so I was intrigued by
this story in the
Telegraph about attempts to power cellphones using the phone conversation itself:
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.”
How on Earth would you do this?
The technology uses tiny strands of zinc oxide sandwiched 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 can then be used to charge a battery.
A prototype of the technology was able to convert sound of around 100 decibels - the equivalent of noisy traffic - to generate 50 millivolts of electricity.
That’s not a lot of power, but researchers are looking at alternate materials to boost it. It’s a cool idea, but I wonder what one of the unanticipated results would be, such as being out in public and constantly hearing people on their phones bellowing: “WE NEED TO TALK LOUDER! MY PHONE’S BATTERY IS RUNNING DOWN!!!!!” Not that we don’t have this already.
On a related note, the
Telegraph story had a link to this story about an
iPod that could be charged by the human heart. All I can say is that if that becomes practical, it might make the accessories section of the Apple Store a bit macabre....
