Improved Control of Concentration Boundary Layer in Microfluidic Fuel Cells

Abstract

In the current work, the new structure for microfluidic fuel cell is proposed to improve the concentration boundary layer and raise the cell performance in consequence. Using COMSOL Multiphysics software and previously validated numerical model, the performance of the proposed design is investigated. Simulation results reveal that by splitting the electrodes which exist on the bottom wall of the microchannel and distributing them with distance on the bottom and top walls, the thickness of concentration boundary layer is controlled. in the proposed structure the electroactive area remains unchanged. By putting the split electrode on two walls of the microchannel there is no need to lengthen the microchannel. Lengthening the microchannel is undesirable because it can cause fuel crossover as the mixing region grows by lengthening the channel. As such, the maximum current density increases up to 60%.

Keywords

• microfluidic fuel cell, COMSOL Multiphysics, concentration boundary layer, laminar flow, microchannel, electrode