Nano-AAO-Based Microsensor for Monitoring Process Carbon Monoxide

This study developed a porous nano anodic aluminum oxide (AAO) based gas microsensor for detecting process carbon monoxide (CO) at room temperature. The small sensing microdevice has stable response with high sensitivity which includes porous AAO structures, gas sensing membrane, interdigitated sensing electrode, heater and temperature sensor. The tungsten oxide (WO3) sensing membrane covers AAO to enlarge total gas sensing surface area to enhance gas sensing response. The Pt interdigitated sensing electrode can also improve the sensitivity. The experimental results showed that the CO gas concentration sensitivity is proportional to temperature. As compared with the sensor without AAO, the concentration range of CO sensed by this microsensor is 100~1000 ppm, the gas sensing resistance change rate can be increased by 87.4 %.