The days of hypothetical, "If you were stranded on a desert island, what would you take with you?" scenarios may be coming to an end. It's all thanks to urine-powered electro-socks — yes, you read that correctly — that could allow you to send a life-saving text message even if there's no outlet to plug into.
A team of scientists at the Bristol BioEnergy Centre (a collaboration between the University of West England and the University of Bristol) have developed what they say is the "world's first self-sufficient system powered by a wearable energy generator based on microbial fuel cell technology (MFC)." In layman's terms, this means an energy generator powered by urine that flows across microbial fuel cells with every step.
The scientists, led by professor Ioannis Ieropoulos, have already powered mobile phones using MFCs and urine, but in that experiment, the urine-tricity (yes, that's what they call it) generator wasn't worn or powered by human activity.
"We wanted to see if we could replicate this success in wearable technology," Ieropoulos says via email of the new tests. "We also wanted the system to be entirely self-sufficient, running only on human power — using urine as fuel and the action of the foot as the pump."
The researchers developed a system based on a simple fish circulatory system; instead of pumping blood, however, they routed urine through tubes using pumps under the wearers' heels. The urine ran across the flexible MFCs embedded in the socks to generate energy — enough energy, in fact, to wirelessly send a message every two minutes to a PC-controlled receiver module. Watch the video below to understand more.
Move over solar and wind. MFCs can convert the bacteria in any type of organic waste directly into electricity. The challenge in scaling up this type of green energy may be finding enough folks who want to handle their own — or anyone else's — urine.
Ieropoulos has an answer for that as well: Use the technology in clothing and gear that already has a urine collection system in place, without people having to carry special catheters. Look, for instance, to this hydroelectric footwear proposed way back in 2001 for an idea of another built-in system.
Ieropoulos imagines applications in the realms of: "military, space, ski or even outdoor/excursion uniforms," he says. "This was only a proof-of-concept demonstration inside our laboratory's controlled conditions, but with a bit of imagination, it is not difficult to see how this could be part of smart textiles for more general use. The main purpose of our work is to utilize what already goes down the drain as waste, and not necessarily to handle it."