Design Of Torque Balance Structure And Silicon Nanofilm Technology For Vector Hydrophone

Vector hydrophone is an important tool to obtain underwater target sound source information.With the development of underwater acoustic sensing technology and micro/nano processing technology,vector hydrophones are developing towards miniaturization,low cost,easy loading and high integration.Aiming at the problem that the vibration of underwater platform affects the detection accuracy and sensitivity of vector hydrophone,a torque balance structure design and silicon nanofilm technology for vector hydrophone are proposed in this paper.Based on the huge piezoresistive effect of silicon nanofilms,hydrophones have higher piezoresistive coefficient than bulk silicon,which can effectively improve the sensitivity of hydrophones.At the same time,the hydrophone is optimized for cilium-silicon column torque balance design,which provides an effective technical means to suppress the platform vibration noise and improve the impact resistance of hydrophone.In this paper,the working principle of the torque balance vector hydrophone,the huge piezoresistive effect of the silicon nanofilm,the suppression analysis of the vibration signal of the hydrophone,the optimization design of the structure size of the hydrophone and the technological process of the hydrophone are introduced.The specific work includes the following:(1)Based on moment balance structure of nanometer silicon membrane theory,acoustic vector hydrophone underwater acoustic sensor principle and introduces the acoustic sensing principle of vibration picking through formula deduction finished underwater acoustic signal to voltage signal conversion,and focused on the giant piezoresistive effect of surface depletion mechanism to improve the sensitivity of hydrophone is a critical technology.(2)The sensitivity and working bandwidth of hydrophone are analyzed theoretically and by simulation.In order to ensure the accuracy of hydrophone detection,the static and modal simulation analysis of MEMS vector hydrophone with torque balance structure was carried out on COMSOL simulation software to optimize the size of hydrophone structure,so as to meet the requirements of underwater acoustic detection.The simulation results of harmonic response of hydrophone show that the vector hydrophone with torque balance structure has obvious effect on suppressing vibration and noise.(3)Based on the characteristics of silicon nanofilms and the limitation of process conditions,the process layout and the whole process flow of hydrophone were designed,and the specific process flow and technical parameters were described in detail.Finally,the vector hydrophone chip sample with torque balance structure based on silicon nanofilms was successfully prepared by MEMS process.Through the I-V curve test,the resistance of the hydrophone chip is 15.3×10~5?,which fully demonstrates the feasibility of the huge piezoresistive effect of silicon nano film in the application of hydrophone chip.