Scientists have created a device that generates energy from human movements. That means now a walk in the park would be sufficient to charge the raft of batteries needed in today's power-hungry gadgets. The first people to benefit could be amputees who are being fitted with increasingly sophisticated prosthetics.

The new device generates power by a process known as "generative braking", analogous to the braking systems found in hybrid-electric cars such as the Toyota Prius. Within each stride muscles are continuously accelerating and decelerating the body.

Source