THE STUDY OF A PIEZOELECTRIC ACCELEROMETER BASED ON D33 WORKING MODE
作者单位：Pen-Tung Sah Institute of Micro-Nano Science and TechnologyXiamen University College of Physical Science and Technology Xiamen University
会议名称：《2016年全国压电和声波理论及器件应用研讨会》
会议日期：2016年
学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学]
基 金：supported by the Scientific Research and Development Program of City of Xiamen (3502Z20143003) the University-Industry Collaboration Program of Fujian Province (2015H6021)
关 键 词：Piezoelectric D33 working mode Interdigital electrode
摘 要：Background, Motivation and Objective Accelerometers fabricated by MEMS technology are in high demand for application in aerospace, automobiles, military systems, and biomedical engineering field. Various acceleration sensing mechanisms have been used in accelerometers, including piezoresistive, capacitive, and piezoelectric. An external power source is required for capacitive and piezoresistive sensors, whereas piezoelectric type sensors can generate the electrical signals by directly converting the mechanical stimuli, thus their operation could consume less energy and does not even necessarily require an external power supply. Besides, piezoelectric accelerometers have a better performance over the other sensing mechanisms in temperature stability and dynamic characteristics. This feature makes piezoelectric accelerometer drawing much attention all over the world in recent years. State of Contribution/Methods Currently, piezoelectric accelerometers are mostly designed in a kind of cross-shaped cantilever structure with four suspension beams supporting a central seismic mass. Electrodes and PZT thin films are sequentially deposited on the suspension beams, forming a sandwich structure. When the mass is subjected to inertia acceleration, it will move vertically. And the piezoelectric thin films will be deformed with the cantilever. Due to piezoelectric effect, charge can be detected from the electrodes. However, the deformation in horizontal directions is very limited, resulting in an extremely low horizontal sensitivity. In our study, a pair of interdigital electrodes is deposited on the top of the piezoelectric thin films to replace the conventional sandwich electrode configuration. In this way the PZT thin films can be polarized in in-plane direction. Analytical and numerical method has been used to study this new type of piezoelectric accelerometer. Results The design can greatly improve the voltage sensitivity from 0.012 m V/g to 4.55 m V/g for vertical direct