Design and Optimization of Gas Sensor Testing Chamber using COMSOL Multiphysics®

K.Govardhan[1], K.Narmada[2], Nirmala Grace[3]
[1]VIT University, MEMS & Sensors Division, School of Electronics Engineering, Vellore, Tamil Nadu, India
[2]VIT University, Sensor System Technology, School of Electronics Engineering, Vellore, Tamil Nadu, India
[3]VIT University, Center for Nanotechnology Research, Vellore, Tamil Nadu, India
Published in 2013

This study aims at the design and optimization of a Gas Sensing Chamber. The design takes advantage of the multiphysics simulation capabilities of COMSOL Multiphysics® to incorporate various physics such as CFD, Micro fluidics, Solid Mechanics, Electro thermal effects etc. The optimization needs to be done at multiple levels such as mixture of two gases, arriving laminar flow over the substrate, thermal conduction of required heat from the heater to the substrate etc. The design needs to be optimized in terms of position of vents, placement of sensor, dimensions of heater, metal oxide coated substrate etc.

Mixing of two inlet gases have been achieved by baffles. The position, angle and gap between the baffles have been optimized to give a good mixture of inlet gases. Positioning of the substrate from the baffles, angle of placement of substrate to the gas mixture flow have been optimized to achieve a good turbulent to laminar transition, enabling a smooth laminar flow over the substrate. Gas sensing characteristics are under study now.