Research On Micro-Displacement Actuator Based On Piezoelectric Ceramics

Micro-displacement technology is an important way to realize ultra-precision machining,and the micro-displacement actuator is a device that can simultaneously realize the positioning accuracy of nanometer level and the stroke of centimeter level.The piezoelectric ceramic plate realizes the micro deformation through the piezoelectric effect,and the periodic driving signal is applied to the piezoelectric ceramic plate,so that the piezoelectric ceramic plate can generate movement.The piezoelectric stack formed by bonding the piezoelectric ceramic sheet with conductive silver adhesive not only maintains the original characteristics and advantages of the piezoelectric ceramic sheet,but also greatly improves its rigidity and output force.Because of its excellent performance,the micro-displacement actuator made of the piezoelectric stack is widely used in nanotechnology,micromachinery and Microsystems,communication sensing technology,electronic scanning technology,microbial technology and other fields.Especially,it can be used as a fine-tuning and positioning device of micro scanning probe microscope under extreme conditions such as extremely low temperature and super strong magnetic field.The research objective of this paper is to design a micro-displacement actuator with strong rigidity and large driving force based on the design and improvement of the overall structure of the micro-displacement actuator.The research work of this paper includes the following points:Firstly,referring to the design structure of a variety of mature micro-displacement actuators,a micro-displacement actuator based on dual piezoelectric ceramic stacks is designed and manufactured independently.I purchase materials to make real objects,manufacture and assemble each component of micro-displacement actuator based on double piezoelectric ceramic stack,and introduce its mechanical structure and working principle in detail.Secondly,through the STM32 single chip microcomputer control system,a set of drive control system for micro-displacement actuator is designed and built to achieve the precise step control of micro-displacement actuator.At the same time,a complete drive amplifier circuit is built independently,which uses OPA454 high-performance amplifier as the main component,and the performance of the drive amplifier circuit is good through experiments.Finally,the relationship between the driving voltage,driving frequency and the pitch of the micro-displacement actuator based on bimorph piezoelectric ceramics is studied by experiment.The experimental results show that the starting voltage of the micro-displacement actuator is 30 V,the minimum forward step is 65 nm,and the minimum backward step is 70 nm.The micro-displacement actuator step is approximately linear with the driving voltage,and has nothing to do with the driving frequency.