Surface Embedded Metal Oxide Sensors (SEMOS)

SEMOS is a joint project between Aalborg University, Danish Technological Institute and Danish Technical University in which micro temperature sensors and metal oxide-based gas sensors are developed and tested in a simulated fuel cell environment as well as in actual working fuel cells. Initially, sensors for measuring the temperatures in an operating HT-PEM (High Temperature-Proton Exchange Membrane) fuel cell are developed for detecting in-plane temperature variations. 5 different tracks for embedded thermal sensors are investigated. The fuel cell MEA (Membrane Electrode Assembly) is quite complex and sensors are not easily implemented in the construction. Hence sensor interface and sensor position must therefore be chosen carefully in order to make the sensors as non-intrusive as possible. Metal Oxide Sensors (MOX) for measuring H₂, O₂ and CO concentration in a fuel cell environment is the second and main part of the project. The main challenges in developing metal oxide sensors are proper choice of the material, sensor location and fabrication technique due to lifetime and cross sensitivity issues in harsh environment where the problems like de-bonding or some kind of diffusion in the form of electrochemical migration or electro-migration due to change in the chemical composition of the sensor material may cause performance degradation of the sensor. The objective of the sensors developed in SEMOS are to aid to the fundamental understanding of the transport and degradation mechanisms occurring in PEM fuel cells. Moreover, the data from the embedded sensors can provide important validation data for numerical fuel cell models and eventually be applied to optimize the overall efficiency.