Design of AlN-Based PMUT with High Electromechanical Coupling Efficiency for Breast Cancer Diagnosis

Chang Liu; Yijun Cheng; Chenyang Xue

doi:10.46604/ijeti.2024.14017

Authors

Chang Liu Department of Electronic and Engineering, Taiyuan Institute of Technology, Shanxi, China
Yijun Cheng Department of Electronic and Engineering, Taiyuan Institute of Technology, Shanxi, China
Chenyang Xue Key Laboratory of Instrumentation Science & Dynamic Measurement, North University of China, Shanxi, China

DOI:

https://doi.org/10.46604/ijeti.2024.14017

Keywords:

PMUT, AlN, electromechanical coupling efficiency, breast cancer

Abstract

The study aims to develop a piezoelectric micromachined ultrasonic transducer (PMUT) with high transmission capability to achieve greater detection depth. The structural design of the sensing cell based on aluminum nitride (AlN) thin film is provided, and a mathematical theoretical model is derived. Static pressure, static displacement, vibration modes, resonant frequency, sensitivity, and acoustic impedance are analyzed using the finite element analysis. The areas of the upper and lower electrodes and the thicknesses of the piezoelectric and vibrating films are optimized. Simulation results indicate that when the ratio of the upper and lower electrodes of the sensing cells is 0.7, the electromechanical coupling efficiency of the transducer is enhanced, and its transmission performance is further improved. Mainly the first-order resonant frequency of PMUT is 7.62 MHz, with a sensitivity of -198 dB and an effective electromechanical coupling coefficient of 10.2%, meeting the design requirements for breast cancer detection.

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