MICRO HUMIDITY SENSOR FOR MONITORING WATER FLOODING IN A PROTON EXCHANGE MEMBRANE FUEL CELL

The operating conditions (relative humidity) of a fuel cell are not ideal, and directly influence performance. A high relative humidity of fuel facilitates flooding with water downstream in the fuel cell, worsening its performance. In this study, a flexible micro humidity sensor is fabricated on a stainless steel foil using micro-electro-mechanical systems (MEMS). It has the advantages of high temperature resistance, small size, high sensitivity, and precision of measurement position. Flexible micro humidity sensors are embedded in a proton exchange membrane fuel cell (PEMFC). Experimental results obtained at a high current density and relative humidities of 100% and 75% demonstrate that the relative humidity midstream and downstream saturated, because of serious flooding by water.