Skip to Content

Socks Generate Electricity Using Microbes Fed by Urine

Yes, you read that right.
December 14, 2015

For once, having socks full of urine and bacteria is a good thing. A pair of sock-like generators, designed by robotics professor Ioannis Ieropoulos’s team at the University of the West of England in Bristol, U.K., are able to turn human waste and locomotion into electrical power with a bit of help from microbes.

James Urquhart, reporting for New Scientist, has the details:

“Walking in the socks forces a bladder’s worth (roughly 648 millilitres) of urine to circulate through integrated tubes towards microbial fuels cells (MFCs), which contain bacteria that guzzle nutrients and create electricity.”

According to Ieropoulous’s team, this is the first time anyone has combined microbial fuel cells with wearable technology. Indeed, the socks produced enough electricity to power a specialized wireless transmitter sending out the message “World’s First Wearable MFC” every two minutes, reports Urquhart.

The crux of the idea was to create a self-contained system for generating power, with an eye toward survivalist scenarios. (Urquhart beat me to the Bear Grylls drink-my-own-urine joke.)

Using microbial fuel cells to generate electricity is nothing new; in fact it seems like Ieropoulos’s lab has cornered the market on piss-based power, operated “a mobile phone, a paper-based transmitter and a 3-D printed robotic heart” using what Utah Gary calls “liquid donations.” In these previous iterations, however, an external power source was needed to power pumps to move the urine around and keep the microbes fed.

The idea for the foot power was not, alas, inspired by Flintstones reruns but by the simplified circulatory system of fish, which is a single closed circuit powered by the simple pumping motion of the heart. Instead of muscular contractions, the sock uses the squeezing power of the human heel to drive the urine around so that it passes through 24 (24!) discrete, flexible MFCs positioned at different points around the sock.

Just as a fish’s muscles need their blood supply kept circulating to keep a fresh supply of oxygen available, the microbes in the MFCs need their urine bath constantly exchanged to ensure a steady supply of nutrients.

The prototype Ieropoulous and his team built did not yet address the issue how exactly to get “liquid donations” into the sock’s tubes. They seem confident, however, that such an obstacle could easily be overcome with a bit of smart textile design to channel the wearer’s waste into their device and exchange it once the nutrient supply ran out. (This calls to mind nothing so much as Dune’s stillsuits, devised to preserve every last drop of a person’s moisture on the desert planet Arrakis.)

In an ideal future, Ieropoulous sees the foot-pump system powering emergency devices to send out SOS signals for people caught away from traditional electricity sources and communications technology. Their system does not generate a tremendous amount of power, but in an outdoor emergency a single text message could make the difference between life and death.

Ieropoulous and his team published their findings in a highly readable paper in the journal Bioinspiration and Biomimetics.

Keep Reading

Most Popular

A Roomba recorded a woman on the toilet. How did screenshots end up on Facebook?

Robot vacuum companies say your images are safe, but a sprawling global supply chain for data from our devices creates risk.

A startup says it’s begun releasing particles into the atmosphere, in an effort to tweak the climate

Make Sunsets is already attempting to earn revenue for geoengineering, a move likely to provoke widespread criticism.

10 Breakthrough Technologies 2023

Every year, we pick the 10 technologies that matter the most right now. We look for advances that will have a big impact on our lives and break down why they matter.

These exclusive satellite images show that Saudi Arabia’s sci-fi megacity is well underway

Weirdly, any recent work on The Line doesn’t show up on Google Maps. But we got the images anyway.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.