Studying the effect of humidity on the Graphene/AlN/Si multilayer structure of SAW chemical sensor

Abstract

This study presents the 2D FEM simulation method and experimental fabrication of SAW- based on multilayer structure Graphene/AlN/Si changes with humidity. The chemical SAW sensor is a type of sensor based on the phenomenon of surface acoustic wave changes. Simulation results show that the center frequency decreases from 127,458 MHz to 127,431 MHz, when the humidity increases from 10% to 100%. And completely in line with the trend of the experimental results, the center frequency is also reduced from 127.6 MHz to 126.7 MHz. Both of these results are consistent with the theory that as humidity increases, the average density of the sensitive layer changes (decreases), resulting in a decrease in the center frequency.