Abstract
This paper describes μ-PEFCs (polymer electrolyte fuel cells) based on MEMS (micro-electromechanical system) fabrication technology. The μ-PEFC has advantages such as batch fabrication, miniaturization, simple assembly and integration with various MEMS components. We propose two kinds of novel structures, "Alternating structure" and "Co-planar structure", which are different from a conventional bipolar structure. The alternating structure has a series of single cells formed in one plane, and the polarization of each single cell is alternately reversed. This structure realizes easy cell interconnection on micromachined substrates without additional wiring. The co-planar structure has a comb-shaped anode and cathode formed on a single substrate, and a thick PEM (polymer electrolyte membrane) formed on the electrodes. This structure has advantages such as simple assembly and independent controllability of membrane humidity from the upper side. We completed a μ-PEFC with the alternating structure. This μ-PEFC has a size of 20×27 mm, and consists of 9 cells with a size of 0.5×15 mm connected in series. In fabrication, some problems including short of the electrodes and pealing of the PEM from the electrodes occurred. Under this incomplete cell condition, the μ-PEFC generated a cell potential of about 0.12 V, when connected to a 10 MΩ resistor, however, the output power was extremely low.
