In this article, a gas sensor with a single detection unit is presented which is applicable for the detection of diverse gases including CH4, NH3, N2, O2, Ar, CO2, C3H8, and their different concentrations in the air background. The proposed Fabry-Perot-based phononic gas sensor is comprised of a detection layer surrounded by thin Steel sheets on both sides. It has been demonstrated that the operating frequency range, the total size of the sensor, the number of detection peaks, and the Q-factor could be adjusted by the width of the detection layer and material use. The functionality of the presented gas sensor has been investigated by the transfer matrix method and the average Q-factor of 1,140,072 and sensitivity of 0.69 MHz.kg-1.m3 are obtained for the structure with a thickness ratio of 9:1 for the Steel and gas layers, respectively regarding pure gases. The maximum average Q-factor and sensitivity of over 106 and 1.03 MHz.kg-1.m3 are obtained for C3H8 gas concerning the concentration increment. The proposed sensor is simple, scalable to operate at any desired frequency range, and provides a multi-peak detection mechanism.
Keywords: Fabry-Perot; Phononic gas sensor; Q-factor; Sensitivity; TMM.
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