Pee power to charge your cellphone

Scientists working at the Bristol Robotics Laboratory have described the "breakthrough" finding of charging cell phones using urine as the power source to generate electricity.

"We are very excited as this is a world first, no-one has harnessed power from urine to do this so it's an exciting discovery. Using the ultimate waste product as a source of power to produce electricity is about as eco as it gets," Dr Ioannis Ieropoulos from University of the West of England (UWE), Bristol, an expert at harnessing power from unusual sources using microbial fuel cells, said.

"One product that we can be sure of an unending supply is our own urine. By harnessing this power as urine passes through a cascade of microbial fuel cells (MFCs), we have managed to charge a mobile phone. 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," said Ieropoulos.

He said so far the microbial fuel power stack that scientists have developed generates enough power to enable SMS messaging, web browsing and to make a brief phone call.

"Making a call on a mobile phone takes up the most energy but we will get to the place where we can charge a battery for longer periods. The concept has been tested and it works - it's now for us to develop and refine the process so that we can develop MFCs to fully charge a battery," he said.

The Microbial Fuel Cell (MFC) is an energy converter, which turns organic matter directly into electricity, via the metabolism of live microorganisms, researchers said.

Essentially, the electricity is a by-product of the microbes' natural life cycle, so the more they eat things like urine, the more energy they generate and for longer periods of time; so it's beneficial to keep doing it, they said.

The electricity output from MFCs is relatively small and so far we have only been able to store and accumulate these low levels of energy into capacitors or super-capacitors, for short charge/discharge cycles.

This is the first time we have been able to directly charge the battery of a device such as a mobile phone and it is indeed a breakthrough, researchers said.

Scientists believe that the technology has the future potential to be installed into domestic bathrooms to harness the urine and produce sufficient electricity to power showers, lighting or razors as well as mobile phones.

The study was reported in the Royal Society of, 'Chemistry Journal of Physical Chemistry Chemical Physics'.