A high performance membraneless microfluidic microbial fuel cell for stable, long-term benchtop operation under strong flow

TL;DR

This paper introduces a robust membraneless microfluidic microbial fuel cell with enhanced stability and power output, capable of long-term operation under strong flow conditions without oxygen scavengers.

Contribution

The study presents a novel design integrating gas diffusion barriers and optimized electrode placement, achieving six months of stable operation and significantly higher power densities.

Findings

Operates for half a year without oxygen scavengers

Power densities are four times higher than previous microfluidic MFCs

Stable performance under high flow rates

Abstract

Strong control over experimental conditions in microfluidic channels provides a unique opportunity to study and optimize membraneless microbial fuel cells (MFCs), particularly with respect to the role of flow. However, improved performance and transferability of results to the wider MFC community require improvements to device stability under all applied operational conditions. To address these challenges, we present an easy-to-fabricate membraneless MFC that combines (i) O2 elimination via a gas diffusion barrier, (ii) integrated graphite electrodes, and (iii) optimized electrode placement to avoid of cross-contamination under all applied flow rates. Attention to all of these design features in the same platform resulted in operation of a MFC with a pure-culture anaerobic Geobacter sulfurreducens biofilm for half a year, six times longer than previously reported, without the use of an oxygen scavenger. As a result of higher device stability under high flow rates, power densities were four times higher than reported previously for microfluidic MFCs with the same biofilm.