Abstract
Microbial fuel cell (MFC) is developed as a renewable energy source, which can simultaneously carries out wastewater treatment. The ability of microorganism in generating extractable electricity highly affects the performance of a MFC; therefore, it is critical to construct a high throughput analysis platform for microorganism screening. Microfluidic MFCs are recently developed for the rapid analysis; however, several challenges remained to be overcome to construct straightforward techniques. This study presents an innovative anode composed of conductive microparticles for encapsulating electricity-generating microbes in microfluidic MFCs. The conductive polymer microparticles (Diallyldimethylammonium chloride, DADMAC) encapsulating microorganisms were generated by a T-junction microchannel. The surface area per volume of the pDADMAC micro-particle was 2.17x106 cm-1 and it can provide extensive surface area for electron transfer. We first examined the electricity generated from these particles using a batch-T ype operation. Microparticles containing microbes generated open circuit voltage (OCV) of 8 mV in the first hour and the OCV gradually decreased to 0 mV in 6 hours, indicating the depletion of substrate. Particles without microbes had relatively stable OCV around 1 mV throughout the operation except for the first 10 min. The conductive microparticles were also applied in an air-cathode batch-T ype MFC and they increased the OCV from ∼0V to ∼20 mV compared with freely suspended microorganisms. These results show the great potential of utilizing the conductive microparticles as anodal electrode in microfluidic microbial fuel cells.