Performance comparison of different geometry parameters for piezoelectric micromachined ultrasonic transducers (PMUT) device

Abstract

This work reports the design of a piezoelectric micromachined ultrasound transducer (PMUT) focusing mainly on Ultrasound-based Diagnostic Imaging System, which is known better as medical imaging. A piezoelectric micromachined ultrasound transducer (PMUT) is one of the technologies available today for medical imaging. It is a Micro-Electro-Mechanical System (MEMS) that can accomplish ultrasonic transmission and reception of a particular frequency by utilizing the piezoelectric effect of piezoelectric films. The optimization is evaluated based on resonant frequencies and the Electromechanical Coupling Coefficient (EMCC) of PMUT, which is affected by the geometry parameters. The performance of PMUTs with different electrode widths, piezoelectric layer widths, and thicknesses is compared using COMSOL simulation. By varying the electrode width within the range of 200 µm to 650 µm, the piezoelectric layer width within 500 µm to 1100 µm, and the piezoelectric layer thickness within 5.35 µm to 11.35 µm, a comprehensive analysis is conducted to determine the sensitivity of the PMUT's performance to these geometry parameters. The most optimum design of a PMUT with the lowest resonant frequencies of 89.6 kHz and highest Electromechanical Coupling Coefficient (EMCC) of 12% is PMUT with a width of the electrode of 650 µm, a width of the piezoelectric layer of 1100 µm and 5.35 µm of the thickness of the piezoelectric layer.