Imagine never needing to worry about a low cell phone battery, or portable video player – that is, if you're wearing a new knee brace capable of powering small electronic devices.
Researchers have developed a knee brace that uses energy from one's normal walking motion to generate electricity on the go. The device can generate enough energy in one minute of walking to to power a cell phone for ten minutes. Remarkably, the brace does not require any meaningful amount of additional work by wearer. It simply utilizes "wasted" energy expended by muscles in decelerating the forward motion of the leg, similar to a hybrid-electric car using the energy from braking.
There are still problems to be solved with the brace, including the way it attaches to the device it powers. Eventually, researchers see important medical applications for the brace, such as powering prosthetic limbs or drug pumps, as well as other practical uses.
You can listen to a podcast from NPR with the inventor, Max Donelan, describing the science behind the device, or read about it in the Newsweek article linked below.