Design and Comparative Analysis of Different Structures of Surface Acoustic Wave Sensor for Hydrogen Gas Detection

The paper presents a comprehensive study on the design and comparative analysis of Surface Acoustic Wave (SAW) sensors for hydrogen gas detection. Three distinct 2D models of sensing layers are investigated: layered structure, nano-rod configuration, and trench configuration between input and output Interdigitated Transducers (IDT). The substrate chosen for these models is lithium niobate(LiNbO3), with platinum(Pt) as IDTs and zinc oxide(ZnO) as the intermediate and sensing layers, respectively. The primary objective is to analyze the variations in displacement graphs of these structures by varying the sensing layer and IDT gap dimensions to find the optimum dimension. Additionally, the frequency shift is studied concerning changes in the concentration of hydrogen gas in parts per million (ppm). The sensitivity and performance characteristics of each model are evaluated and compared through finite element simulations on COMSOL software.