Any geek can tell you that battery life hasn't kept up with gadget innovations. But not to worry: Inventors are figuring out how to turn geeks into batteries.
While most gadget lovers hunt for empty wall sockets to charge their devices, Kevin Bartholomew just plugs his cellphone into his hip. That is where he keeps a nine-inch device looped around his belt that converts the kinetic energy of his motion into enough power to keep his devices running.
Mr. Bartholomew's tube-shaped personal energy generator, called the nPower PEG, can turn 15 minutes of walking into a minute of phone talk time.
It is a good alternative to finding a plug, depending on how much exercise you get, says the 31-year-old electrical engineer from Logan, Utah.
The latest in body-powered technology includes gizmos that absorb excess energy produced by motion, like the jiggle of a backpack or bend of a knee. There are T-shirts that capture the electricity in sound waves, boots that convert walking into energy and solar panels that attach to everything from pants to bikes.
A tech truism called Moore's Law holds that computing power will grow exponentially, as transistors get smaller. But it doesn't apply to batteries. Apple Inc.'s latest iPhone 4S comes with eight hours of talking time—exactly as much as the original iPhone model that came out in 2007.
The battery deficit has created a market opportunity for companies like Goal Zero, of Salt Lake City. It first started making personal-size solar panels in 2007 for cellphones in Africa, but found a need among gadget addicts closer to home, says President Joe Atkin. Last year, he sold some 200,000 foldable 14-inch solar chargers. "It is about freedom," says Mr. Atkin.
Marc D. Latrique, a media liaison at the United Nations in New York, carries his personal solar panel with him every day "just in case, for any reason, I'm stuck in a situation where I won't have access to an outlet," he says.
While solar panel technology has been around for a long time, recent innovations have made the panels portable and efficient enough for folks to use as everyday personal power generators.
To keep the juice flowing, Mr. Latrique, 38, seeks out windows and sunny patches in the street. In pursuit of power, he has wrapped his panel around his jeans and clipped it to his backpack. In an clumsier episode, he accidentally set it afloat on a Hawaiian beach.
On a recent flight, he hooked his panel up to the plane window to charge his daughter's iPod. "My daughter said, 'Oh, Daddy, you are saving the planet.'" His response: "No, I'm just being convenient."
There is much more potential to energize humans, say inventors.
Last summer, for the Glastonbury music festival in Scotland, British phone carrier Orange produced T-shirts that used a so-called piezoelectric panel to convert sound pressure waves into electricity. The panel allowed those standing close enough to the speakers to charge a smartphone.
One finding: The "Sound Charge" shirts collected more energy with dance music than jazz or classical, says Mat Sears, a spokesman for Orange parent company Everything Everywhere. That is because bass notes—more common in dance tunes—carry more energy. "But it didn't seem to care who was singing," he says.
Zhong Lin Wang, a professor at the Georgia Institute of Technology, is tackling a new kind of power suit—made from fabric that uses nanotechnology to generate energy as the body moves around.
Any wrinkle in shirts, pants—even undergarments—made with the fabric produces a charge, he says. The trick involves super-slim wires, measuring one-thousandth the width of a strand of hair, that are woven into the fabric. When the specially treated plastic and zinc material moves, it creates mechanical energy that can be harvested by a capacitor, so nobody gets shocked.
Mr. Wang's self-powering clothes are at least two years away, he says.
Knees are another frontier. Max Donelan has been working for roughly a decade on a device that captures energy as people walk with a generator attached to their legs.
Knee muscles naturally push and pull upon one another to speed the body up and slow it down, he says. The device, which is being made by a company called Bionic Power Inc., captures energy by selectively turning on a generator at certain parts of the stride.
"As long as you're walking, you have access to energy," says Mr. Donelan, who is Bionic Power's chief science officer. The downside is comfort: His knee braces weigh roughly two pounds per leg, about the same as one worn by a professional basketball player.
The nPower PEG, used by Mr. Bartholomew, was one of the first commercial kinetic energy generators when it came out last year—and its maker, Tremont Electric Inc., is already sold out.
The idea came to inventor Aaron LeMieux, 37, when he was backpacking along the Appalachian Trail. "I was always stopping into towns to buy batteries to keep my electronics running," he says. "I was paying $10 or $12 for a pack of batteries that are heavy, expensive and didn't supply all the power I needed."
His solution is a metal rod that produces energy when a mechanism inside moves up and down with the motion of the person wearing it.
But it is not for the sedentary geek. "It won't take your iPhone off the power grid unless you're a long-distance backpacker," says Mr. LeMieux.
Victor Sherwood, 24, rarely goes out without the PEG sitting upright in his backpack to build up a charge, he says.
One time, though, the field IT engineer left his PEG unshaken in his car for several days exactly at a moment when he needed it: during a late-night job at a warehouse when his phone ran out of juice.
So Mr. Sherwood turned himself into a human power station, running around and shaking his PEG up and down like a jackhammer, to create more energy.
"I got enough of a charge that I could call the boss and tell him that my phone was dead," he says.