In situ diagnosis of micrometallic proton exchange membrane fuel cells using microsensors

This work utilizes the microsensors that are fabricated on metallic bipolar plates to measure temperature and humidity in an operating micro-proton exchange membrane fuel cell (PEMFC). Bipolar plates were constructed of stainless steel (SS-304), and the flow channel was formed on a stainless steel substrate by wet etching. The micro-temperature and humidity sensors were fabricated using micro-electro-mechanical-systems (MEMS) technology. The sensors were located on the flow channel rib. Experimental results demonstrate that the operating temperature of fuel cell was 41.54 °C, which was measured by a micro-temperature sensor and the temperature outside the fuel cell was 37 °C, measured using a thermocouple. The gas flow rate of H2/O2 was 200/200 ml min−1 without humidification. The maximum power density of the fuel cell without and with microsensors on bipolar plates was 142 mW cm−2 and 56 mW cm−2, respectively.