Development Of Piezoelectric MEMS Bionic Structure Vector Acoustic Sensor

With the implementation of marine power policy, to strengthen the development, management, utilization and control of the ocean is the focus of future sustained and healthy development. In order to solve the low frequency, long distance, multi target object recognition, an urgent need to address the key issues is: exploration, research and development of the vector acoustic sensor to achieve miniaturization, low frequency precise detection and to enhance the sensitivity.Based on the bionic principle, piezoelectric effect and MEMS technology, piezoelectric MEMS vector acoustic sensor can solve the above problems. This paper is designed based on the piezoelectric effect of MEMS bionic vector hydrophone, through the principle of bionics and piezoelectric effect makes the design of underwater acoustic sensor sensitivity is improved; by MEMS technology and the piezoelectric principle, batch fabrication of passive devices, to achieve miniaturization. The designed sensor has the advantages of small size, wide dynamic measurement range, low noise and high sensitivity.This paper analyses the piezoelectric effect on aquatic animals lateral line sensory conduction of the bionics theory and material, through theoretical analysis on the design of underwater acoustic sensor, the devices demonstrate the feasibility. Based on the above theory, design four fiber type cantilever beam is connected to the center of the body structure, the mathematical model is established, the natural frequency, sensitivity, stress and stiffness were analyzed, and through MATLAB and ANSYS simulation, analysis and comparison. In the MEMS processing technology platform to complete the production of the device base chip, assembly. The model prototype of the piezoelectric MEMS bionic vector acoustic sensor is manufactured by imitating the aquatic animal sensor and completing the bionic package.Finally, the test platform for the initial completion of the prototype model of the sensitivity of the calibration experiment. The experimental results show that the designed hydrophone has light weight, small size, and has the characteristic of “8”. The sensitivity is-192.2d B@500Hz(0d B 1V/ μPa), the frequency band width is 20~300Hz. The depth of directive concave points of 100 Hz is larger than 20 d B, and asymmetry of the maximum axial sensitivity value is less than 0.2d B;The depth of directive concave points of 300 Hz is larger than 23.5d B, and asymmetry of the maximum axial sensitivity value is less than 0.8d B.