A HIGH POWER DENSITY MEMS MICROBIAL FUEL CELL

We report a microfabricated microbial fuel cell (MFC) that produces a high power density using a Geobacteraceae-enriched mixed bacterial culture. The MFC features 4.5-L anode/cathode chambers defined by 20-m-thick photo-definable polydimethylsiloxane (PDMS). The short proton diffusion length (20 m) in the anode lowers electrolyte resistance and consequently enhances power generation. A maximum current density of 16.3 mA/cm 3 and power density of 2.3 mW/cm 3 are achieved. The start-up time is only 2 days for maximum current generation. The MFC was operated under semi-continuous flow conditions, and L-cysteine was added in order to chemically scavenge the dissolved oxygen in the anode chamber.