Good Vibrations.(International Edition; TECHTONIC SHIFTS)(kinetic energy)(Report)

Byline: Sophie Grove

Anyone who thinks running on a treadmill in the gym is a futile exercise should talk to Steve Beeby. The British scientist, a microsystems expert at the Engineering and Sciences Research Council, hates to see all those potential watts go to waste. For nine years he has been working on ways of tapping kinetic energy--the energy from moving objects--to power electronic gadgets. His research team at the University of Southampton has developed a device that converts surplus vibrations from industrial machinery into electrical power. Now Beeby and other scientists think the world is humming (literally) with possibilities: shuddering railway cars, flexing joints and even the stomp of London's rush-hour commuters could all be tiny, renewable sources of power.

The principle of energy harvesting is nothing new. Remember that clunky bicycle dynamo, which connected pedals and gears to a generator? The first kinetic (self-winding) clock was invented in the 1770s. In the past few years, however, the need to power a proliferation of digital gadgets such as wireless sensor networks --mobile data-collection devices--has triggered a new look into this science. The idea is simple: each time an object vibrates, the energy from the motion can be harnessed to generate electricity, extracting energy from vibrations that currently goes to waste. Vibrations cause magnets to quiver, generating a current in a copper coil; about 30 percent of the kinetic energy gets converted into electrical power. Such opportunistic energy-catching usually yields mere microwatts of power but has big potential to supply juice to small devices--such as environmental sensors and accelerometers that monitor bridge stress and traffic-tracking systems--that are turning up everywhere, and for which batteries are costly, cumbersome and difficult to replace. In the last few years the technology has gained ground in the medical, military and mechanical industries. "These are parasitic devices," says Beeby. "We're using vibrations already there in the environment."

Researchers at Imperial College in London are working on a bionic-powered pacemaker that harnesses energy from the beating of the heart. The contraption keeps a tiny battery charged, which kicks in when the heartbeat falters--"rather like a solar-powered flashlight that uses the sunshine to power itself and then works in the dark when you need it," says Paul Mitcheson, who leads the study. The new-style pacemaker is still just a prototype and has yet to be inserted into a human body, but Mitcheson hopes that the device "could prevent the need for replacing pacemakers every six or seven years, which at the moment involves complex heart surgery."

Some eco-savvy consumer-oriented companies are ...