Power is under your foots!

An interesting idea would be useful to generate electricity by footsteps. It is interesting that anymore generating electricity by foots are real. Have you ever thought that you will charge your laptop or mobile phone by the energy of your foots.

University of Wisconsin-Madison researchers have come up with a technique that collects considerably more energy from human footfalls and converts it into electric power.Previous researches has yielded with less than 1 watt power but it wasn't enough for charging, but the new approach could lead to a shoe-mounted generator that produces up to 10 watts, says Tom Krupenkin a mechanical engineering professor who works on this project.

"A lot of energy is simply wasted as heat while we walk," says Krupenkin. "If one can convert this into electrical energy, numbers come out to be up to 10 watts per foot." Cell phones and smart phones need about one to two watts, while small laptops need 10 to 12 watts. Power-generating shoes could be an important breakthrough for soldiers, who currently carry heavy batteries to power their radios, GPS units, and night-vision goggles.

Energy collecters keep this force and convers displacement into electrical energy. The most promising approaches to tap into the human gait have involved piezoelectrics and electroactive polymers, materials that convert mechanical stress into electric power. But neither material works well with the relatively high displacements, but low frequency, of footfalls, Krupenkin says.

Finishing project could take in one or two years then, you can buy a power-generating shoes, though. So far the researchers have only an array of 150 drops that made ​​a few milliwatts of power. However, they calculate that a 1,000-unit drop in a four-meter-long, one millimeter-wide channel that would cover an area of ​​40 square centimeters and could fit in a shoe sole to produce a few watts.

"The process is interesting, and the work itself is very good," says Paul Wright, a mechanical engineering professor at the University of California at Berkeley. However, he says, "to be useful to society, they would need to scale up the approach and show that it still works."

Krupenkin and his colleagues have established a startup, InStep NanoPower, to develop and possibly commercialize the technology. The company has a first-generation benchtop-sized prototype device. They expect the third generation harvester could be embedded in footwear. "This kind of product will have to be a collaborative project between Instep and a shoe manufacturer," Krupenkin says. "We can't expect anything on the market earlier than two years."

technologyreview.com