High-sensitivity SAW micro-pressure sensor with cantilever beam structure: optimization of IDT and electrode

SAW sensors are distinguished by the compact size, passive wireless operation, and sensitivity to multiple physical parameters, which assure widely applications across various fields. We present the design of a highly sensitive SAW micro-pressure sensor featuring a multi-layer structure and an inertial cantilever beam. The working principle is theoretically analyzed, and finite element method (FEM) simulations are conducted to compare the performance of cantilever beams, simply supported beams and circular membranes. The optimal placement of interdigital transducers (IDTs) is determined, the effects of dimensional parameters and material properties are assessed with performances of broadened frequency range and improved sensitivities. The fabrication process is finalized besides the developed testing system. Experimental results confirm high sensitivity to micro pressure, with distinct resonant frequency shifts observed under varying pressure conditions.