Design and control of a novel asymmetrical piezoelectric actuated microgripper for micromanipulation

Abstract

Microgripper is an important tool in high precision micromanipulation task, which directly affects the quality and efficiency of micromanipulation. This paper presents the design and control of a novel asymmetrical microgripper driven by a piezoelectric (PZT) actuator. The developed microgripper is designed as an asymmetrical structure with just one movable jaw, so it has the advantages of no dense mode and fixed locating datum compared with the symmetrical microgripper with two movable jaws. The main body of microgripper is a compact flexure-based mechanical structure with a three-stage amplification mechanism. Based on the designed structure, large-range, robust and parallel grasping operation can be realized. The characteristics analyses of the developed microgripper are carried out by finite element analysis (FEA). A position-force switching control strategy is utilized to regulate the position and grasping force of movable jaw. Discrete-time sliding model controller (DSMC) is designed to control the position and grasping force of grasping jaw. Experimental studies are conducted and the results show that the microgripper exhibits good performance and high precision grasping operations can be realized through the developed control strategy.

Microgripper design and evaluation for automated µ-wire assembly: a survey

“…Various shapes of hinges have been studied in previous literature. Circular notch hinges are an increasingly popular design of flexible hinge as studied in previous literature (Liang et al 2018;Wang et al 2013aWang et al , 2015Kyung et al 2008;Nah and Zhong 2007;Shi et al 2018;Keoschkerjan and Wurmus 2002). This type of flexible hinge contains many advantages including being capable of achieving a large defamation prior to exceeding the tensile yield limit of the material being used.…”

“…This piezoelectric actuated microgripper has been developed in this manner to increase the precision of the gripper. When a conventional two moving jaw microgripper grasps hold of a micro-object, the jaws of the gripper often dis-align from a central position and thus effect the consistence and accuracy of the system (Liang et al 2018). The single movable jaw structure comprises of a moveable jaw and a fixed jaw.…”

“…The single movable jaw structure comprises of a moveable jaw and a fixed jaw. During the gripping process the micro-object will be held by both jaws, however the fixed jaw will remain in a constant position before and after the process and hence is a relatable constant point of the jaw (Liang et al 2018). The microgripper also comprises of three different amplification systems from the piezoelectric material to the gripper jaws, which converts a small displacement from the material to a large jaw tip displacement of 75 lm (Liang et al 2018).…”

“…During the gripping process the micro-object will be held by both jaws, however the fixed jaw will remain in a constant position before and after the process and hence is a relatable constant point of the jaw (Liang et al 2018). The microgripper also comprises of three different amplification systems from the piezoelectric material to the gripper jaws, which converts a small displacement from the material to a large jaw tip displacement of 75 lm (Liang et al 2018). Another survey reviewed a large quantity of various microgripper actuators and concluded that the piezoelectric actuated microgrippers studied were capable of producing jaw displacements between 16 and 8800 lm while the applied voltage ranged from 0 to 700 V for different microgrippers (Dochshanov et al 2017).…”

Design of a Compliant Mechanism Based Four-Stage Amplification Piezoelectric-Driven Asymmetric Microgripper

“…Zhao et al [30] designed a two stage asymmetric microgripper based on the principle of lever amplification, which realized the stable gripping of the jaws and improved displacement amplification. Based on the principle of lever amplification and triangle amplification, Liang et al [31] designed a three stage asymmetric microgripper, which realized the parallel gripping, but the amplification was smaller than that of Li et al [24], Sun [26], and Wang [27].…”