Tuesday, 18 December 2012
Generate Electricity From The Human Body
Turning the human body into a power station sounds like a zany plotline from the Matrix movies, but scientists are starting to take seriously the idea that one way to stem climate change might be to harvest tiny amounts of energy in the form of the body’s heat, movement, metabolism and vibrations.
In one form of the technology, experts are turning to piezoelectricity, which means “electricity resulting from pressure”. In a piezoelectric material, small amounts of power are generated when it is pushed out of shape. As an extraordinary example of what’s now possible with these materials, the heart itself could be used to power an artificial pacemaker. Though these devices require only tiny amounts of power – one millionth of a watt – their batteries typically run out after a few years. But as Dr Amin Karami at the University of Michigan says, a pacemaker that harvests the energy of the heartbeat itself might operate for a lifetime. In a recent address to the American Heart Association in Los Angeles, he pointed out that a sliver of a piezoelectric ceramic one hundredth of an inch thick, powered by vibrations in the chest cavity, is able to generate almost 10 times the power required to operate a pacemaker.
The technology can be used on the outside of the body as well. Nanotechnology researchers are developing the perfect complement to the power tie: a “power shirt” woven from pairs of fibres coated with tiny strips of zinc oxide and gold. As you move, the fibres rub against each other to produce a current. Prof Zhong Lin Wang, at the Georgia Institute of Technology, says that “we could provide a flexible, foldable and wearable power source that, for example, would allow people to generate their own electrical current while walking”.