"Construction workers need to hold tools to become more productive, and you and me might want to climb Kilimanjaro and need extra power from a bionic leg, " he said.
An accessory device designed to be worn on a leg or arm could greatly benefit from this sort of power generation, and could lengthen the amount of time between charging.
Its second-generation Ankle Mimicking Prosthetic Foot (AMP-Foot 2.0) uses a pair of force sensors to determine the leg's relative position and let an actuator build energy when the foot bends, locking the power away to use only when the owner pushes off.