The challenge is to make practical MFCs that produce enough electricity to power devices in the real world. A report scheduled for the May 15 issue of Environmental Science & Technology now provides researchers with reassurance that practical MFCs are possible. The study was done by Willy Verstraete and colleagues, of the Laboratory of Microbial Ecology and Technology at Ghent University in Belgium.

Researchers had hoped to get higher voltage or more current by connecting multiple MFCs together, much like batteries stacked inside a flashlight. However, they faced uncertainties about how stacking MFCs might affect the electricity-producing microbial populations inside each fuel cell.

Verstraete's research focused on how stacking of MFCs and the evolution of the microbial communities inside the MFCs influenced the electric output. "This is the first report that relates the evolution of the electrochemical and microbial features of MFCs," he noted.