New Microbial Fuel Cell Design Has Moved The Technology Closer To Realization

Penn State environmental engineers have removed and replaced one of the most expensive parts of their prototype microbial fuel cell and the device now costs two-thirds less and produces nearly six times more electricity from domestic wastewater.
Earlier this year, the Penn State team was the first to develop a microbial fuel cell (MFC) that can generate electricity while simultaneously cleaning domestic wastewater skimmed from the settling pond of a sewage treatment plant. Now, they've shown that by modifying their original MFC to make it cheaper, they can also boost electricity production from about 26 milliwatts per square meter to about 146 milliwatts per square meter.

Bruce Logan, the Kappe professor of environmental engineering, directs the project. He says, "The new design has moved the technology closer to our goal of 1,000 milliwatts per square meter."

Microbial fuel cells produce current through the action of bacteria that can pass electrons to an anode, the negative electrode of a fuel cell. The electrons flow from the anode through a wire to a cathode, the positive electrode of a fuel cell, where they combine with hydrogen ions (protons) and oxygen to form water.