Development of Thermal Conductivity Type Hydrogen Sensor

In fuel cell system, it is more desirable to monitor hydrogen concentration in fuel gas line for effective power generation and avoiding fuel starvation. For this need, we have developed MEMS hydrogen sensor which employs thermal conductivity measurement as its sensing principle. This sensor has a micro heater on MEMS diaphragm which enables to detect small heat release rate by hydrogen gas flow. This application requires enough robustness in highly humidified fuel gas stream with possible exposure to rich organic silicon contaminants from sealants. We have optimized the sensor design to overcome these technical hurdles by preventing dew condensation inside sensor housing and with simplified sensing algorithm.