Discrete-holes film fueling anode heads for high performance air-breathing microfluidic fuel cell

Microfluidic fuel cells is one of the most promising micro power sources for the portable micro-electronic devices. Facing the requirement of high performance, in this work, a novel air-breathing microfluidic fuel cell (AMFC) with discrete-holes film fueling anode is developed by inputting the idea of gas film cooling, where fuel is fed into the capillary tube and then outflows through the discrete holes to fuel the catalyst layer by annular film flow, enabling fuel transfer enhancement. Idea of the new AMFC architecture is realized, and the annular film flow based on film fueling is visualized and proved by fluorescence microscopy at various flow conditions. In addition, the cell performances under various annular film flow patterns are compared at equal total fuel supply. The effects of fuel concentration and fuel flow rate on fuel transport and cell performance are investigated and discussed in detail. And the maximum power density of 361.9 mW cm −3 is obtained. These results are in favor of promoting the practical application of microfluidic fuel cells.