Employment of osmotic pump as a novel feeding system to operate the laminar-flow microfluidic microbial fuel cell

Abstract

Laminar-flow microfluidic microbial fuel cell (LMMFC) has attracted attention due to the advantage of the liquid-liquid interface between anolyte and catholyte without the use of membrane as a separator resulting in less fabrication cost. Unlike previous studies of LMMFC using syringe pumps, this study proposes the use of osmotic pumps to feed anolyte and catholyte in the microchannel without any additional power supply. The osmotic pump was constructed with two cylindrical chambers separated by a forward osmosis membrane, with the initial draw solution concentration of 90 g l−1 NaCl. We have, for the first time, demonstrated using the osmotic pumps to deliver both anolyte and catholyte and create co-laminar flow in LMMFC. Under the catholyte and anolyte flow rates of 18 ml/h and 40 ml/h respectively, LMMFC cultivated with Shewanella oneidensis produced the maximum power density of 87 mW m−2 and current density of 747 mA m−2 with the internal resistance of 1660 Ω. Further studies are warranted to develop osmotic pumps-fed LMMFC into a potential platform for portable biosensors.