High Aspect Ratio Bipolar Plate Fuel Cell Micro-Patterning Using Aluminum Oxide as a Masking Layer

This article reports a recent development of fabricating the flow channel of bipolar plates for direct methanol fuel cells (DMFC). Aluminum oxide film prepared by atomic layer deposition was used as a masking layer for the silicon etch in the deep reactive ion etching. The device design and fabrication of the bipolar plates are discussed. An aspect ratio of 20 was achieved for a 200-micron deep trench.