Effects of the nanoimprint pattern on the performance of a MEMS-based micro direct methanol fuel cell

In this paper, nanoimprint technology is presented as an excellent candidate for replacing conventional graphite-based porous electrodes for a more compact and thinner micro direct methanol fuel cell (DMFC). High catalyst efficiency is realized in a MEMS-based passive micro DMFC by directly forming fine patterns on a polymer electrolyte membrane by the nanoimprint method. The MEMS-based micro DMFC has a maximum power density (MPD) of about 0.2 mW cm ^-2 with a Pt catalyst loading of about 0.04 mg cm^-2. The MPD is much higher than those of the reported micro DMFCs with similar catalyst loading. We also investigated the relationship between the cell performance, the nanoimprinted patterns and the catalyst. A good match is necessary between the nanoimprinted patterns and the catalyst layer for high catalyst efficiency. It is mainly owing to the fact that the Pt catalyst layer plays the function of a current collector in the prepared MEMS-based micro DMFC. Higher performance could be enabled by improving the catalyst layer and the nanoimprinted patterns.