Design and Simulation of ZnO based Acetone Gas Sensor using COMSOL Multiphysics

Acetone gas is a breath marker for diabetes detection. Metal oxide gas sensors have been widely used for gas sensing applications. Zinc oxide (ZnO) is a promising material for Acetone gas detection. Metal oxide semiconductors require a high-temperature environment for detecting the target gas. The temperature generated from the micro-heater has a great influence on the concentration of gas adsorbed on the surface and also the resistance of the sensing layer. The temperature should be uniformly distributed on the surface of the heater for the better performance of the sensor. In this work, a meander shaped micro-heater is used for the ZnO sensor for Acetone gas detection. The Scanning electron microscopic image of the synthesized ZnO was found to have a spherical shape and the same structure was given for the sensing layer in the simulation. Platinum is used as the heating material because of its high thermal conductivity and low power consumption. The variation of the temperature of the heating material with respect to the input voltage was analyzed. The variation of the resistance of the sensing layer with respect to the target gas was also analyzed. The resistance of the sensing layer was found to decrease in the presence of Acetone gas. The simulation was done using COMSOL Multiphysics.