Study Of A Micro-Piezoelectric Accelerometer Based On D₃₃ Mode

Piezoelectric micro-accelerometer has become a hot topic for researchers in global due to its outstanding dynamic performance and response speed.After more than 30 years of research,many breakthroughs have been made in aspects of device structure,functional material preparation and microfabrication processes.This article is mainly based on the problem of current piezoelectric micro-accelerometer on the output sensitivity,which is mainly restricted by the difficulty of preparing thick PZT film.We proposed a new kind of d33 mode design to reduce the influence of the film thickness on the performance of micro-accelerometer by making the polarization direction and deformation direction of PZT film been horizontal.By this design,the sensitivity of the piezoelectric accelerometer is increased while its natural frequency is kept constant.In this way,the practicality of the piezoelectric accelerometer can be increased.The main contents and innovations of this article include the following aspects:1)The difference between the two different piezoelectric transduction modes was analyzed and compared.It is analyzed that the d33 mode has a great advantage than the d31 mode.2)Through theoretical analysis and finite element simulation,the characteristic dimensions of the piezoelectric accelerometer have been studied and used to determine the performance of the accelerometer.3)Through the study of the d33 mode,the entire microfabrication process was determined.Based on the processing plan,a MASK design was performed and the main process steps were explored.4)In order to further improve the practicality of the piezoelectric micro-accelerometer,a cold-discharge charge amplifier circuit was designed for signal detection.