Finite element analysis of surface acoustic wave based on a micro force sensor

• We present the elastic stiffness matrix, the stress, and the size of IDT as the three problems.
• The FEM can be used in simulate the substrate that possesses good linearity in performance.
• The work proposes three different kinds of substrate in contrasting the suitable size of the sensor.

The finite element method (FEM) is regarded as the most appropriate and effective method of numerical analysis for surface acoustic wave (SAW) devices. This paper presents the FEM for SAW devices based on a micro force sensor; the method calculates the structure of the interdigital transducer (IDT) based on LiNbO3. Theoretical studies, realization, and characterization of the pressure sensor in different SAW sizes are researched. The strain and stress of SAW based on a micro force sensor subjected to different pressures are calculated and analyzed using the Christophe and wave propagation equations. The minimum and maximum deformations of the substrate length in the mechanical analysis are established through the ANSYS software. Experimental results for the measured pressure sensitivity of the device show that the design has reasonable detection circuit and stability of frequency and amplitude.