Nanoimprint of Polymer Electrolyte Membrane for Micro Direct Methanol Fuel Cell Application

This paper reviews current progress on the miniaturization of direct methanol fuel cell (DMFC) by micro-electro-mechanical systems (MEMS) technology. MEMS-based DMFC has low performance because of low catalyst efficiency. Thermal nanoimprint technology is presented as an attractive method for achieving high catalyst efficiency. Fine patterns were directly formed on Nafion 117 membrane by using thermal nanoimprint method. With passive feeding of 1 M methanol solution and air, the nanoimprinted micro DMFC prototype had a open circuit voltage (OCV) of about 0.74 V and a maximum power density (MPD) of 0.2 mW/cm2, which were much higher than those of the state-of-the-art MEMS-based micro DMFC with similar catalyst loading, suggesting that much higher catalyst efficiency had been realized. This conclusion was also supported by the fuel cell experiments on the nanoimprinted membrane using humidified hydrogen and oxygen at 60oC.