A stroll around the park may soon be enough to charge the raft of batteries needed in today's power-hungry gadgets.
US and Canadian scientists have built a novel device that effortlessly harvests energy from human movements.
The adapted knee brace, outlined in the journal Science, can generate enough energy to power a mobile phone for 30 minutes from one minute of walking.
I can't help wondering how much human-power could be harnessed without rendering workaday life unbearable. Could becoming a carbon-based bipedal battery even become fashionable, given time? With the right combination of unobtrusive technology, I don't see why not.