A tiny microbial fuel cell that processes urine into electricity has been created by researchers at the University of Bath in the UK. The device could be a sustainable and affordable alternative to fossil fuels to generate power, costing only from AU$2 to AU$4.

In collaboration with the Queen Mary University of London and the Bristol Bioenergy Centre, the researchers designed this one-inch squared device to work on the bacteria found in urine and other organic matter. A single microbial fuel cell can generate two watts per cubic metre, which is lower compared to hydrogen or solar fuel cells but it is still has the edge in the long run since the technology can be manufactured at extremely cheap cost. It also uses a fuel that will never disappear and produces nearly zero harmful gases.

“Microbial fuel cells can play an important role in addressing the triple challenge of finding solutions that support secure, affordable, and environmentally sensitive energy, known as the ‘energy trilemma,” says University of Bath’s Mirella Di Lorenzo. “There is no single solution to this ‘energy trilemma’ apart from taking full advantage of available indigenous resources, which include urine.”


(Left to right): Ph.D. student Jon Chouler, Senior Lecturer in the Department of Chemical Engineering, Dr. Mirella Di Lorenzo, Senior Lecturer in the Department of Chemistry, Dr. Petra Cameron. Credit: Tim Gander

The fuel cell uses a carbon catalyst at the cathode. The catalyst is obtained from glucose and an egg protein called ovalbumin. Other microbial fuel cells use a platinum catalyst, which is more expensive and unsustainable.

They found that increasing the electrodes from four millimetres to eight millimetres significantly increased the generated power. Piling multiple fuel cells together also maximised the power output.

The researchers are currently studying how to adjust the design of the device to increase the power generated. Further developments would increase the cell’s performance and could help especially those who cannot afford to pay expensive electricity bills.

“Microbial fuel cells could be a great source of energy in developing countries, particularly in impoverished and rural areas,” adds lead author Jon Chouler. “To have created technology that can potentially transform the lives of poor people who don’t have access to, or cannot afford electricity, is an exciting prospect. I hope this will enable those in need to enjoy a better quality of life as a result of our research.”