Study On Piezoelectric MEMS One-dimensional Vector Hydroacoustic Sensor

The ocean plays an important role in opening to the outside world and in national economic development,and plays an important role in safeguarding national sovereignty,national security and national development interests.To build China into a maritime power,we must further understand the ocean and accelerate the pace of Marine scientific and technological innovation.Sonar technology is an important means to explore the ocean,and the hydroacoustic sensor,as its core component,can help Chinese deep-sea scientific research to the international frontier.Combined with MEMS(Micro Electro Mechanical System)processing technology,the one-dimensional vector hydroacoustic sensor with four-helical beam structure is designed based piezoelectric effect.Firstly,the theory of sound propagation in water and the working principle of the hydroacoustic sensor were studied.The vibration model of the vector hydroacoustic sensor was analyzed.The PZT(Pb(ZrxTi1-x)O3)film for d31 mode was selected as the piezoelectric functional material to preliminarily design the one-dimensional vector hydroacoustic sensor.Complete modal analysis and static analysis and forecast performance of the piezoelectric one-dimensional vector acoustic sensor.Complete the process design and layout design,preparation of PZT thin film with(111)preferred orientation and realize the heterogeneous integration between PZT film and 4 inches SOI(Silicon On Insulator)wafer.Do MEMS processing to get the chip for piezoelectric one-dimensional vector acoustic sensor,and lead to complete preliminary packaging.The tests for vibration test system and calibration test system of the underwater acoustic sensor were completed,and the stability,consistency and reliability of the device were preliminarily tested by the vibration system test.The acoustic signal is tested by the underwater acoustic calibration system,and the sensitivity of the acoustic sensor designed in this paper is calculated by the comparative calibration method.The results show that the designed piezoelectric one-dimensional vector acoustic sensor has a high sensitivity(-191 dB@500 Hz,-184 dB@1000 Hz).