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Microbial fuel cells (MFCs) harvest energy from a wide variety of natural carbon sources to produce electricity at neutral pH and ambient temperatures. To date, standard H2/O2 PEMFC technology has yet to generate significant power under those conditions. Because most environments on earth are exposed to significant levels of oxygen, we believe the transition from sediment based MFCs to oxygen-tolerant MFCs is necessary. This transition would require both a way to simultaneously sequester the metal-reducing microbes and reduce the overall concentration of oxygen in the anode chamber. Recent work suggests that power can be generated with significant oxygen in the anolyte when using three dimensional (3D) electrodes in a miniature MFC design; potentially expanding the role of MFCs to function in more diverse regions (i.e., water column, air/water interface). Exposing the anode to air will also create unique growing conditions for the microbes themselves compared to the standard anaerobic anode conditions used in MFCs.