Miniature fuel cell creates power for smartphone from just one visit to toilet
Published 11/07/2016 | 12:56
A miniature fuel cell costing no more than £2 which can generate electricity from a single visit to the toilet has recharged a smartphone for the first time.
Using "pee power", scientists have been able to provide three hours of phone calls for every six hours of charge time - all from 600ml of urine.
The microbial fuel cell technology provides enormous potential to enable people to stay connected in areas that are off grid using urine.
The world first has been developed at the University of the West of England in Bristol by Professor Ioannis Ieropoulos and his team.
Prof Ieropoulos said: "We are excited to announce several global firsts - this development was possible by employing a new design of microbial fuel cells that allowed scaling up without power density losses.
"Although it was demonstrated in the past that a basic mobile phone could be charged by microbial fuel cells, the present study goes beyond this to show how, simply using urine, a microbial fuel cell system successfully charges a modern-day smartphone."
Several energy-harvesting systems have been tested and results have demonstrated that the charging circuitry of commercially available phones may consume up to 38% of energy on top of the battery capacity.
Each of the fuel cells costs between £1 and £2 and works by using natural biological processes of "electric" bacteria to turn urine into electricity.
Urine passes through the microbial fuel cell for this reaction to happen, with the bacteria then generating electricity.
This can be stored or used to directly power electrical devices.
The fuel cell measures just one inch square in size and uses a carbon catalyst at the cathode which is derived from glucose and ovalbumin, a protein found in egg white.
This catalyst is a renewable and much cheaper alternative to platinum, which is commonly used in other microbial fuel cells.