A membrane-free micro-fluidic microbial fuel cell for rapid characterization of exoelectrogenic bacteria

A membrane-free micro-fluidic microbial fuel cell (μMFC) has been developed in this work, in which the bacteria-mediated organic fuel oxidation process is physically separated from the proton exchange process that occurs between the laminar co-flows of anolyte and catholyte streams on a micro-fluidic chip. This new strategy aims to shelter exoelectrogenic bacteria in the anode chamber from the potential influence of the agents from the catholyte stream and enable much larger anode surface for bacteria adhesion in order to enhance the electron transfer efficiency. This μMFC reveals considerable difference in the relative open-circuit voltage produced by Shewanella oneidensis MR-1 and Escherichia coli DH5α, which can be established and stabilized within 2 h. This platform can be used for rapid characterization of the exoelectrogenic capability of various microorganisms or the development of a microbe-based electrochemical biosensor.