Development of MEMS-based direct methanol fuel cell with high power density using nanoimprint technology

Performance of MEMS-based DMFC is low, because graphite-based porous electrodes show poor compatibility with MEMS technology. Nanoimprint technology was adopted in this paper to prepare fine pattern on proton exchange membrane (PEM) in MEMS-based DMFC as a promising alternative to the graphite-based porous electrodes. Micro-convex with the diameter of about 600 nm and the height of 50-70 nm was prepared on Nafion^® 117 membrane by the nanoimprint at 130 °C using silicon mold. Thick Pt film (20 nm) was deposited as catalyst directly on the nanoimprinted Nafion^® 117 membrane. Then the Pt-coated PEM was sandwiched with micro-channeled silicon plates to form a micro-DMFC. With passively feeding of 1 M methanol solution and air at room temperature, the as-prepared cell had the open circuit voltage (OCV) of 0.74 V and the maximum power density of 0.20 mW/cm². The measured OCV was higher than those (0.1-0.3 V) of the state-of-the-art MEMS-based DMFC with planar electrode and pure Pt catalyst.