Co-Flow Microbial Fuel Cells

Abstract

Microbial fuel cells (MFCs) are electrochemical devices that use bacteria as a vehicle to oxidize organic and inorganic matter to produce electricity. Previous effort has developed proton exchange membrane (PEM) MFCs, which integrate continuous fluid flow and use the membrane as a physical barrier between anodic and cathodic compartments. Recently, fuel cells have been developed to take advantage of the ability of low Re fluids to flow side by side down a microchannel without convective mixing. The liquid-liquid interface acts as a membrane, through which fast protons are transported, so co-flow devices do not suffer the problem of membrane degradation that their PEM counterparts do. This paper evaluates the design, fabrication, and testing of a microfluidic co-flow MFC using the bacterial strain Shewanella oneidensis MR-1. Technical challenges in the proof of concept experimentation are systematically worked through and the design of other working co-flow devices are adapted to come up with two possible co-flow MFC fabrication procedures.