Design, Analysis, and Experiment on a Novel Stick-Slip Piezoelectric Actuator with a Lever Mechanism.

Weiqing Huang,Mengxin Sun

doi:10.3390/mi10120863

Abstract

A piezoelectric actuator using a lever mechanism is designed, fabricated, and tested with the aim of accomplishing long-travel precision linear driving based on the stick-slip principle. The proposed actuator mainly consists of a stator, an adjustment mechanism, a preload mechanism, a base, and a linear guide. The stator design, comprising a piezoelectric stack and a lever mechanism with a long hinge used to increase the displacement of the driving foot, is described. A simplified model of the stator is created. Its design parameters are determined by an analytical model and confirmed using the finite element method. In a series of experiments, a laser displacement sensor is employed to measure the displacement responses of the actuator under the application of different driving signals. The experiment results demonstrate that the velocity of the actuator rises from 0.05 mm/s to 1.8 mm/s with the frequency increasing from 30 Hz to 150 Hz and the voltage increasing from 30 V to 150 V. It is shown that the minimum step distance of the actuator is 0.875 μm. The proposed actuator features large stroke, a simple structure, fast response, and high resolution.

Highlights

Though the piezoelectric effect was discovered more than a century ago, research on piezoelectric is still ongoing [1,2,3,4,5] and attracts attention in many areas [6,7,8,9,10]
Actuators can be classified by vibration state into the resonant type and the non-resonant type
The resonant type is the traditional one and is called the ultrasonic motor. This type is already widely used in precision positioning, nanotechnology, and biomechanics, among other things [15,16,17,18,19]

Summary

Introduction

Though the piezoelectric effect was discovered more than a century ago, research on piezoelectric is still ongoing [1,2,3,4,5] and attracts attention in many areas [6,7,8,9,10]. The flexure mechanisms set in the actuators are the connecting joints to implement high precision motion, and the amplification mechanism of the system This type of actuator operates with the flexure mechanism to amplify the displacement of the stator per period, which increases the output speed of the mover. Experiment results showed that the maximum mean velocity was about 5.5 mm/sec, and the length of the each step was about 275 nm [36] In these studies, the vibration of the piezoelectric stacks caused rectangular or elliptical motions at the top of the driving feet. As the driving feet are in contact with the linear guide by appropriate preload force, the micro-vibration at the top of the driving foot is transformed into the macro-linear motion of the guide These actuators have high resolution and fast response, the structure and control mechanisms are complex. The accuracy of the theoretical model is verified by experiments, and the characteristics of the prototype are tested

Structure of the Actuator

Working Principle

Conclusions