AC Impedance Investigation of Flooding in Micro Flow Channels for Fuel Cells

The paper presents a study on the transport phenomena related to gas flow through fuel cell micro-channels, specifically the impact of dimensional scale on the order of 100 microns and below. The use of structural photopolymer (SU-8) enabled the direct fabrication of functional fuel cell micro-channels. Previous experimental observation has revealed that if flow channels are too small, they may reduce the performance of fuel due to flooding (Cha et al., 2003). For further investigation, AC Impedance technique has been employed to measure the mass transfer resistance. The result confirmed that in smaller channels, mass transportation resistance increases due to the flooding.