~e; electromagnetic body-power

From bc <human@electronetwork.org>
Date Sun, 30 Dec 2001 20:11:04 -0600

Unlocking the Power of the Body Electric

December 27 2001

Scientists are working on tiny batteries that capture energy derived 
from motion and heat for military and civilian uses.

By Dave Wilson

American soldiers slogging though Afghanistan use constant radio 
communication, satellite navigation and night vision goggles. Today, 
a single grunt has capabilities and powers a battalion couldn't call 
on just a couple of decades ago.
But the gizmos that give a commando godlike abilities devour power. 
There was a time not so long ago when all an infantryman had to carry 
were a weapon and ammo. Now he's got to drag around a couple of 
pounds of batteries for stuff like his range finder.
Some servicemen have to lug a pack that tops 100 pounds, depending on 
the mission. When gear gets that heavy, the choice comes down to 
packing an extra AA battery or another couple of rounds for the 
rifle. There's only so much weight a man can carry before he looses 
his effectiveness as a soldier--and in many cases, a battery can be 
more important than a bullet. That is one reason so many researchers 
are trying to capture electricity derived directly from human bodies 
to power portable devices. Although much of the research has been 
aimed at military applications, low-end civilian uses for this 
technology will appear soon, perhaps even next year. And someday, the 
ability to self-generate power might help dramatically redesign many 
everyday things.
For decades, the normal movements of the human body have powered some 
smaller gadgets. The best example is a self-winding watch, which uses 
the frequent motion of the human arm to wind a spring and keep the 
clock mechanism moving.
Several researchers, such as Joe Paradiso, head of the responsive 
environments group at the Massachusetts Institute of Technology's 
Media Lab, have installed tiny power generation equipment in shoes. 
Every step generates a burst of electricity. Properly controlled, 
that's the sort of thing that could power a radio.
"The trick here is storing the electricity in some kind of battery, 
so that the power doesn't stop if you're not walking around," 
Paradiso said.
Other researchers are thinking about other ways to tap the energy 
created by the human body. One of the most common methods is based on 
a well-understood principle that the difference in temperature 
between two objects can be converted into electricity. Advanced Power 
Solutions Inc. of Palm Beach, Fla., said its tiny thermoelectric 
generator will be used in a wristwatch that may be on the market next 
year. The generator creates electricity based on the difference in 
temperature between skin and air.
Why should anybody care about this?
"Beyond the life-and-death decisions on the battlefield, which is the 
focus of much of the research today, many people think this kind of 
technology will help us conserve energy in the future," said Henry W. 
Brandhorst, director of the Center for Space Power and Advanced 
Electronics at Auburn University. NASA is funding the center's power 
research for use on space missions.
Look for the technology eventually to filter down to consumer devices 
such as mobile phones and electronic organizers. "We depend on 
batteries, and they always seem to fail us at the worst possible 
time," he said. "I just tried to turn on my Palm Pilot yesterday and 
nothing happened."
Tapping into the power human bodies produce holds out the possibility 
of making medical devices largely self-contained. Someday, a cardiac 
patient may not need to get his chest cracked open every few years to 
replace the pacemaker battery.
But the technology's most profound effect may be in the way people 
design and interact with portable devices.
Battery power dictates the size and shape of just about every 
electronic gizmo. Part of the reason pagers clip to a belt instead of 
being worn as rings or shirt buttons is the size of the batteries 
needed to power them.
Someday, however, with clothing that collects and stores electricity, 
and gadgets designed to draw power from that system, form really will 
follow function. Gadgets will be no bigger than they need to be to do 
the job. Which means soldiers will be able to carry more of the 
lifesaving gear they need to do their jobs.
But Paradiso of MIT said that day won't arrive soon.
"People love this idea, but there's a lot of work that needs to be 
done. Making all this work at that level is going to be pretty hard."
Dave Wilson is The Times' personal technology columnist. He can be 
reached at dave.wilson @latimes.com.

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