Walking for Watts: Sneaker Insole Harvests Electricity, Could Power iPhone

Human locomotion generates kinetic energy.
No step goes to waste. (Photo: Tom Krupenkin and J. Ashley Taylor)
Aug 24, 2011· 1 MIN READ
Salvatore Cardoni holds a political science degree from the George Washington University. He's written about all things environment since 2007.

Maybe this will convince the 72.9 percent of obese or overweight Americans to hit the treadmill: researchers in Wisconsin have designed a sneaker insole that captures the electricity generated by the walker’s steps, reports Mother Nature Network.

The power could be used to juice up a broad range of devices like smart-phones, laptops, or night vision goggles, but the inventors say that the concept is years away from being market-ready.

The news comes weeks after we reported on a nanotechnology breakthrough that converts sound into electricity, allowing a mobile to be powered up while a conversation is in progress.

Conceived by University of Wisconsin researchers Tom Krupenking and Ashley Taylor, the technology hinges on an idea known as “electrowetting.”

MNN breaks down the science behind the insole:

In [electrowetting] a droplet of a conductive liquid is placed on an electrode and is deformed by the application of electric charge. But Krupenkin took the concept in a different direction, what the researchers call "reverse electrowetting." In this case, microscopic droplets are placed between multilayer thin films; as the droplets move—in this case, from the energy of a shoe landing on the ground—energy is produced.

Several factors—the speed and weight of the walker as well as the efficiency of the device—will end up determining how much power the shoe produces.

Right now, Krupenking and Taylor are estimating between 1 and 10 watts.

As if the concept’s awesome quotient couldn’t get any higher, the researchers say that no direct physical connection is required to bridge the insole and the wireless device.

This means that energy could be transferred easily with a Bluetooth through a wi-fi connection.

To bring their concept to market, Krupenking and Taylor have formed InstepNanoPower and are actively seeking out investors.