Planar air-breathing micro-direct methanol fuel cell stacks based on micro-electronic-mechanical-system technology

To meet the demands for high power micro-electronic devices, two silicon-based micro-direct methanol fuel cell (μDMFC) stacks consisting of six individual cells with two different anode flow fields were designed, fabricated and evaluated. Micro-electronic-mechanical-system (MEMS) technology was used to fabricate both flow field plate and fuel distribution plate on the silicon wafer. Experimental results show that either an individual cell or a stack with double serpentine-type flow fields presents better cell performance than those with pin-type flow fields. A μDMFC stack with double serpentine-type flow fields generates a peak output power of ca. 151 mW at a working voltage of 1.5 V, corresponding to an average power density of ca. 17.5 mW cm^-2, which is ca. 20.7% higher than that with pin-type flow fields. The volume and weight of the stacks are only 5.3 cm³ and 10.7 g, respectively. Such small stacks could be used as power sources for micro-electronic devices.