For people who need a source of battery power that is both cheap and abundant...
As it cascades through a series of fuel cells, hungry bacteria consume it and release electrons, which generate an electrical current.
Now, the team reports that these energy-converting microbial fuel cells (MFCs) have successfully used urine to directly power a cellphone battery.
"One product that we can be sure of an unending supply is our own urine," BRL's Ioannis Ieropoulos said in a news release. "The beauty of this fuel source is that we are not relying on the erratic nature of the wind or the sun; we are actually re-using waste to create energy."
After a full day of charging, a Samsung cellphone worked for 25 minutes -- enough to send several texts and make a 6-minute, 20-second call.
With each fuel cell only costing around £1 to produce, the Independent reports, such devices could provide a new, cheaper way of generating power.
The team hopes the device will help people in remote areas stay connected. Perhaps in the future, it can be installed in bathrooms and produce sufficient electricity to power razors and lights. They're also aiming to have something that can be carried around easily.
The research was sponsored in part by the Gates Foundation, and the team is currently bidding for funding to work alongside partners in the U.S. and South Africa to develop a smart toilet.
The work was published in Physical Chemistry Chemical Physics last week.
Image: bigbirdz via Flickr