Modeling and Simulation of TiO2/Se Sensor for Detection of CO Gas Using Comsol Multiphysics

Abstract

Metal oxide sensors are being used from past three decades. They still suffer from some disadvantages, such as high operating temperature, high power consumption, sensor stability, and cross sensitivity. Since the cost of development of these sensors is high, it is important to develop a mathematical model to economically predict the behavior of these sensors. In this context, research work focused on evaluating the performance of these sensors using numerical analysis software. In this work, modeling and simulating the gas sensing properties of Titanium dioxide/Selenium (MOS) sensor material to detect carbon monoxide (CO) gas using Comsol Multiphysics software has been proposed. The gas sensing simulation was performed using ‘Reaction engineering,’ ‘Transport of diluted species,’ ‘Surface reactions,’ and ‘Laminar flow’ interfaces of Comsol Multiphysics software on Titanium dioxide/Selenium material. Two kinds of simulations, space independent and space dependent simulation, was performed on this material in a constant volume gas chamber. The geometry was created in space dependent node, Comsol. The carbon monoxide gas was injected through gaussian pulse feed inlet at different concentrations (1 ppm, 5 ppm, 10 ppm, and 15 ppm) into the gas chamber and MOS sensor layer was allowed to reach steady state. The adsorption simulation on sensor layer exposed to carbon monoxide (CO) gas shows the change in surface concentration of the adsorbed CO molecules on the sensor layer.