Zang Junbin, Fan Zheng, Li Penglu, Duan Xiaoya, Wu Chunsheng, Cui Danfeng, Xue Chenyang
Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China.
Micromachines (Basel). 2022 Aug 14;13(8):1317. doi: 10.3390/mi13081317.
A piezoelectric micromachined ultrasonic transducer (PMUT) is a microelectromechanical system (MEMS) device that can transmit and receive ultrasonic waves. Given its advantages of high-frequency ultrasound with good directionality and high resolution, PMUT can be used in application scenarios with low power supply, such as fingerprint recognition, nondestructive testing, and medical diagnosis. Here, a PMUT based on an aluminum nitride thin-film material is designed and fabricated. First, the eigenfrequencies of the PMUT are studied with multiphysics coupling simulation software, and the relationship between eigenfrequencies and vibration layer parameters is determined. The transmission performance of the PMUT is obtained via simulation. The PMUT device is fabricated in accordance with the designed simple MEMS processing process. The topography of the PMUT vibration layer is determined via scanning electron microscopy, and the resonant frequency of the PMUT device is 7.43 MHz. The electromechanical coupling coefficient is 2.21% via an LCR tester.
压电微机械超声换能器（PMUT）是一种能够发射和接收超声波的微机电系统（MEMS）器件。鉴于其具有高频超声、方向性好和分辨率高的优点，PMUT可用于低电源的应用场景，如指纹识别、无损检测和医学诊断。在此，设计并制造了一种基于氮化铝薄膜材料的PMUT。首先，使用多物理场耦合仿真软件研究了PMUT的本征频率，并确定了本征频率与振动层参数之间的关系。通过仿真获得了PMUT的传输性能。根据设计的简单MEMS工艺制作了PMUT器件。通过扫描电子显微镜确定了PMUT振动层的形貌，PMUT器件的谐振频率为7.43MHz。通过LCR测试仪测得机电耦合系数为2.21%。
