Smart toothbrushes, smartwatches, smart locks, smart washing machines - almost anything you can name these days has been graced with sensors and connectivity powers. But are any of them are powered by urine?

Yes. Yes they are.

Scientists at the Bristol Energy Centre have created a pair of socks which have an in-built wireless transmitter that’s capable of sending a message to a PC, and there’s no battery or charger in sight.

The socks are embedded with microbial fuel cells which use bacteria to generate electricity from waste fluids. Waste fluids in this case, being the wearer’s urine.

Instead of… letting loose and allowing the fluid to flow freely down and saturate the socks (apologies for the mental imagery) it is instead collected and transported to the socks via a series of soft tubes.

A manual pump, based off the design of a fish’s heart and circulatory system, then keeps the microbial fuel cells topped up with urine with each step, thanks to a series of tubes placed in each heel which compress with each step, acting as a pump.

Currently the system is capable of wirelessly transmitting an on-screen message to a PC, but we don’t expect the socks themselves to hit shelves any time soon.

Think of it more as a proof-of-concept showing off a completely human-powered, self-sustained system, as opposed to the next-generation’s answer to smartphone battery woes.

[IOP Science]