Development of hazardous gas sensors with ultra-thin insulation layer for low power consumption

Abstract

Even in today’s era with extraordinary technological advancements and achievements, toxic gas related deaths are frequently occurring due to the lack of reliable and available toxic gas sensors. Implementing a reliable toxic gas sensor into our everyday smart devices, we expect a significant reduction in gas intoxication related deaths. However, with the current research level, gas sensors consume too much power for smart device integration without significantly draining its battery. In this paper, a perfectly-aligned nanowire array based on nanotechnology as the heater and sensor, along with an ultra-thin insulation layer, has resulted in a significant decrease in gas sensor’s power consumption. Conventional bottom-up nanowire formation technique requires a thick insulation layer for mechanical support during the release process due to the random assortment and arrangements of nanowires. However, this paper has utilized a top-down fabrication method that results in a continuous and uniform nanowire structure that is mechanically stable even without a thick insulation support layer. By utilizing the reliable top-down fabrication method and employing an ultra-thin insulation support layer, the proposed gas sensor was able to achieve 3.5 mW of operating power. The proposed sensor is capable of detecting various carbon monoxide gas levels from 30 ppm to as low as 1 ppm with extraordinary sensitivity and response time. The presented techniques offer a promising direction towards integrating a reliable gas sensor into a battery-driven smart device to guarantee the prevention of gas intoxication.