Power though goo

Scientists have boosted the power output of microbial fuel cells more than 10 fold by letting the bacteria congregate in a biofilm.

The research, led by microbiologist Derek Lovley of the University of Massachusetts Amherst, suggests that efficient technologies for generating electricity with microbes are much closer than anticipated. Lovley presented the results yesterday, May 10 in a plenary talk at the meeting of the Electrochemical Society in Denver.

A typical fuel cell converts fuels to electricity without the need for combustion and microbial fuel cells work the same way. They usually comprise two compartments, or cells, which are separated by an electrically insulating membrane. In one compartment, microorganisms pull electrons and protons from some sort of fuel, such as waste organic matter. These protons and electrons are attracted to molecules in the second compartment (usually oxygen) and will move towards those molecules. The protons do this by passing through the membrane. But the electrons can’t go through the membrane and so must travel via an alternate route; a wire or electrode that connects the two compartments. It is this flow of electrons through the electrode that supplies power.