Current Research In Human Energy Harvesting

An electromagnetic knee braces that uses a computer to help control excess motion was developed at Professor Max Donelan's Locomotion Lab at Simon Fraser University. The generator fires up when you are on the swinging phase of your walking motion. Walking one minute is enough to charge a cell phone for half an hour. The military is interested in this research because soldiers may carry up to 30 pounds of batteries for their equipment, and this device is only 3 lbs, though a 1 lb weight is now being developed.

A similar principle was used to develop a backpack, which is also of extreme interest to the military. The movement of the wearer generates oscillations that are converted into electricity. This is done by the walker causing the bag to bounce on a spring that uses gears to connect to an electrical generator. The motion produces 20 watts, enough to power most portable devices, but it is heavy at 80 pounds. The inventor is Professor Larry Rome of the University of Pennsylvania.

At Professor Zhong Lin Wang's Lab at the Georgia Institute of Technology, researchers have used nanotechnology to create clothes that are responsive to human movements. Specially made crystals are interwoven into fibers, and when these crystals are forced to bend by rubbing into each other, electricity is generated.

Body heat and sunlight is used to power batteryless brainwave reading headphones. Hitachi is developing a device that turns the motion of blood in the brain into electricity to switch channels.

The brainchild of two MIT grad students, the idea here is to use the kinetic energy of humans in crowded urban settings, such as from that of trains or concerts. The energy from people sitting, walking, or jumping would be transformed into electricity that could be used to power signs and other devices. As a test case that was performed at an Italian train site, the students did a demo where the weight of person sitting on a stool caused a flywheel to spin, thus powering a dynamo that in turn powered four LEDs.

One idea is that walking would depress a sub-flooring system comprised of blocks that would move in response. The slippage of the blocks against each other would be converted into electricity via the same process as that of a dynamo. Because a human step can only power two 60 watt lightbulbs for a second, this concept is best applied to a crowd, where over 28,527 steps can produce enough power for a moving train for one second. With enough steps, say 84,152,203, one can power the launch of a space shuttle.

For more on the progam, including pictures, visit MIT's School of Architecture and Planning website.

Energy Harvesting Journal

Popular Science's Harvesting Energy From Humans

MIT's Crowd Farm Project

Image Credits

Crowd Farm Stool courtesy of MIT's School of Architecture and Planning Website

Clothes by Jade