压电式MEMS水听器振膜结构的幅频特性检测研究

Amplitude-Frequency Characteristics Testing of the Diaphragm Structure in Piezoelectric MEMS Hydrophones

摘要:

介绍了一种使用反射式数字全息显微镜检测压电式 MEMS 水听器中振膜结构幅频特性的方法。首先采用光学方法测量得到水听器上振膜结构的静态形貌，再利用压电材料的逆压电效应对压电薄膜施以一定区间频率的电激励，经数字全息显微镜表征动态三维形貌，记录振膜在不同频率下的动态响应情况，以获得其特征频率、 特征频率处的振型等关键信息。试验结果表明，该方法能较好地表征振膜结构的静态形貌、特征频率、振型等特性，有助于加速压电式微机电系统（MEMS）水听器的迭代开发。

Abstract:

This paper introduces a method for detecting the amplitude frequency characteristics of the diaphragm structure in piezoelectric MEMS hydrophones using a reflective digital holographic microscope. The static morphology of the diaphragm structure on the hydrophone was measured using optical methods. Then， the inverse piezoelectric effect of piezoelectric materials was used to apply electrical excitation to the piezoelectric film at a certain frequency range. The dynamic three-dimensional morphology was characterized via a digital holographic microscope， and the dynamic response of the diaphragm at different frequencies was recorded to obtain key information， such as its characteristic frequency and mode shape， at the characteristic frequency. The experimental results show that this method can effectively characterize the static morphology， characteristic frequency， mode shape， and other characteristics of the diaphragm structure， which aids in accelerating the iterative development of piezoelectric MEMS hydrophones.