Design Performance and Frequency Response Analysis of SAW-Based Sensor for Dichloromethane Gas Sensing Amidst the COVID-19

Abstract

BackgroundTo avoid the risk of increase in the rate of human infection is a big challenge for healthcare staffs during the treatment of patients affected from corona virus disease-2019 (COVID-19). This work is intended to save COVID-19-infected patients from conveyed hazardous volatile gases (VOCs) by the gas stream. The VOCs are generally generated from the pathways of medical respiratory devices.MethodHere, we present a surface acoustic wave-based sensor device for sensing dichloromethane (DCM) gas that can be connected with a gas pathway system used in medical devices. Dichloromethane is a volatile organic compound. Single- (polyisobutylene, PIB) and multi- (polyisobutylene/silicon nitride, PIB/Si3N4) surface acoustic wave-based sensors are designed on LiNbO3 piezoelectric substrate. The designed models patterned with interdigitated transducer (IDT) aluminum (Al) electrodes are used to analyze gas sensing behavior for dichloromethane (CH2Cl2, DCM) gas.ResultsThe studies for DCM gas sensing are carried out for single- and multi-layer models using COMSOL Multi-physics software. The resonant frequency and displacement are also observed for 100 ppm gas concentration of DCM at room temperature. It has been found that multi-layer designed model shows higher sensitivity as compared to single layer (PIB/LiNbO3) model on exposing DCM gas.ConclusionThe estimation of various parameters observed by the proposed module is also explained. It is observed that the sensitivity of sensor for detection of VOCs (generated in gas pathways in medical devices) is best suited in the present crisis of COVID-19 pandemic.