Pore Morphology Study of Porous Electrodes Using Eddy Current Sensor

Porous electrodes are used for the fabrication of different vapour-sensors including capacitive and resistive sensors. The capacitive sensors in Shaw Moisture Meter, UK, use porous gold electrodes for moisture detection in gases. The porous electrodes play an important role in the sensing performance parameters of a thin film/thick sensor. At present, costly analytical instruments are used to study the pore morphology of porous materials. This paper introduces a novel eddy current sensor for investigating the pore morphology of metal electrodes. The sensor is designed and simulated using COMSOL Multiphysics software for the most commonly used interdigital electrodes with various pore sizes. Finally, the sensor is fabricated and experimentally validated using a Keysight LCR meter at 100 kHz. Results demonstrate the effectiveness of the proposed method offering a valuable non-destructive testing technique for analyzing the pore morphology of the porous electrode (sensitivity 0.9 H/mm).