High aspect ratio microreactor for MEMS fuel cells

In this paper, we investigated the fabrication of high aspect ratio micromolds using a commercially available AZ9260 positive photoresist^® and a reactor for a miniature fuel cell having high aspect ratio structures with large surface area by metal plating in conjunction with the micromolds. A conventional contact mask aligner with standard UV light sources was used for creating micromolds. A photoresist thickness up to 24 μm on a silicon substrate was accomplished by employing a multiple coating process. The line pitch of the electroplated metal line is 9 μm (7.5 μm reactor line width and 1.6 μm space). The aspect ratio of about 15 was achieved in the structure of the microfabricated reactor with a 24 μm thickness.