Modeling and Simulation of Novel Semiconducting Metal Oxide Gas Sensors for Wearable Devices

Our work focuses on the design and rigorous evaluation of two novel designs for semiconducting metal oxide (SMO) gas sensors with different shapes and sizes, in order to assess the most efficient layout geometry in terms of power consumption, membrane stability, and temperature distribution. The aim of this paper is to provide two designs, one to be used for a thin sensing film and the other to be applied with a nanowires sensing layer. Both designs implement innovative aspects, allowing for an improvement in state-of-the-art sensors' selectivity and power consumption, which make the product suitable for use on a wide variety of applications. To further support the simulation results, an analytical model based on a Cauer network is presented for estimating the power consumption of the device. We demonstrate the ability of SMO sensors to operate at 300 °C with high uniform temperature over the sensing material and ultra-low power consumption of roughly 8 mW. In addition, a microheater array design is presented, which is able to heat two active sensing layers to 270 °C and 350 °C simultaneously in 40 μs. Both designs are analyzed for stability, and it was found that the stress generated in the membranes and the resulting deformation is minimal, improving the device stability and reliability.