An In Situ Signal Amplification Sensor for Measuring In‐Plane Current Density Distribution in a Proton Exchange Membrane Fuel Cell

Abstract

Inconsistency of current density distribution in‐plane in fuel cells is a common phenomenon. This study develops a novel highly integrated sensor with the feature of signal in situ amplification for measuring in‐plane current density. First, the sensor is designed and fabricated based on the idea of in situ amplification of in‐plane signals before transmission. Then, the sensor accuracy is quantitatively evaluated prior to fuel cell experiments based on a single‐point calibration approach. Finally, the distribution of in‐plane current density is observed using the sensor in the fuel cell test system. Additionally, the measurement accuracy of the circuit current in the test bench is compared by introducing the calibrated segment average amplification factors. The results indicate that these signals amplified by the sensor can effectively withstand the effects of signal transmission loss and interference, and it can be determined that the measurement accuracy of the sensor is controlled within 97% in the small current range and within 98% in the nonsmall current range in normal operation. This work provides a feasible solution for in situ measurements of in‐plane current density, with significant improvements in signal acquisition, structural matching, and fabrication process compared to existing such sensors.