Development of a Capacitive Pressure Sensor Based on Nanoporous Anodic Aluminium Oxide

Capacitive pressure sensors make pressure sensing technology more accessible to a wider range of applications and industries, including consumer electronics, automotive, healthcare etc. However, developing a capacitive pressure sensor with brilliant performance using a lowcost technique remains a difficulty. In this work, the development of a capacitive pressure sensor based on nanoporous AAO fabricated by a two-step anodization approach which offers a promising solution for precise pressure measurement is fabricated by a two-step anodization approach. A parallel plate capacitive sensor was fabricated by placing two AAO deposited sheets are placed face to face, with the non-anodized aluminum component at the base functioning as the top and bottom electrodes. A variation in the capacitance value of the as fabricated sensor was observed over an applied pressure range (100 Pa-100 kPa). This change in capacitance can be attributed to the decrease in the distance between the two plates and the non-homogenous distribution of contact stress and strain due to the presence of nanoporous AAO structure. In this pressure range the sensor showed high sensitivity, short response time and excellent repeatability which indicates a promising future of the fabricated sensor in consumer electronics, intelligent robotics etc.