Electrochemical Hydrogen Sensor Assembly for Monitoring High‐Concentration Hydrogen

The demand for hydrogen energy is rapidly increasing because of its clean, abundant, and efficient nature. To utilize hydrogen gas as a fuel for fuel‐cell vehicles, several types of hydrogen sensors are needed to address cost and safety issues. Precise monitoring of hydrogen gas concentration is critical in optimizing vehicle fuel‐cell efficiency. Herein, a fully packaged hydrogen sensor to continuously measure a hydrogen concentration of 20–100% with environmental variations is fabricated, including temperature (from −40 to 105 °C), humidity (from 10 to 98 RH%), and pressure (from 30 to 350 kPa). A signal‐processing circuit is designed to reduce the error rate, and a sensor chip and printed circuit board are assembled in a module using a packaging process with robust materials for harsh vehicle environments. The result herein suggests direct application of the sensor to monitor hydrogen concentration in the hydrogen recirculation unit in a fuel‐cell vehicle.