Knee Brace Could Generate Enough Power for Electronic Prosthetics

Just like a hybrid auto engine generates electricity while a car rolls to a stop, a new knee brace works by creating resistance when the leg stops with each step. Already the prototype can power a cell phone. Later versions may be able to power computerized and motorized prosthetic knees on the opposite leg.

Such knees are already on the market. Otto Bock's C-Leg uses a computer chip to control hydrolic fluid, thus regulating the speed and resistance on a prosthetic knee. A much heavier, bulkier knee, Ossur's Power Knee, has a motor that powers the lower leg and bluetooth chips that pick up signals from the sound leg. The problems with all of these designs are that they need to be plugged in overnight and the batteries add weight and bulk, something many older amputees cannot tolerate.

If hopes for this new power-generating brace work out, it would provide the electricity for these devices so they can become much smaller, lighter, and versatile.