https://www.mdpi.com/2218-6581/5/2/11/pdf

State of the Art Robotic Grippers and Applications

Recent trends in piezoelectric actuators for precision motion and their applications: a review

Design and manufacturing of mobile micro manipulation system with a compliant piezoelectric actuator based micro gripper

This paper is a study on the hybrid position/force control of a two-fingered miniature gripper driven by piezoelectric bimoph cells. The system is composed of the flexible cantilevers and a compact force sensor attached to the tip of one finger. Control action is applied by two piezoelectric bimorph strips placed at the base of each finger. The theoretical model of the electro-mechanical system is developed and applied to the study of a control problem where the gripper is commanded to grasp its object with a time-constant force 0.01 N at a prescribed commanded fingertip position. The PID control algorithm is introduced to drive the gripper.The system control behaviour is examined both theoretically and experimentally.

http://petit.lib.yamaguchi-u.ac.jp/G0000006y2j2/file/16323/20110721164516/2009010409.pdf

Soft-handling gripper driven by piezoceramic bimorph strips

This paper reports the design and modelling of a new piezo-driven microgripper with large output displacements. The design of the microgripper is based on the double-rocker mechanism and the parallelogram mechanism. The microgripper can produce a large output displacement and a parallel movement of the gripper tips. Theoretical models for the microgripper are derived using the pseudorigid-body-model method. Through several finite-element analysis simulations, the optimal geometric parameters of the microgripper are obtained, and the theoretical models are evaluated and verified. The performance of the proposed microgripper is demonstrated by several experiments, and a micromanipulation case is presented. The experimental results indicate that the microgripper with the double-rocker mechanism has a large output displacement of 213.9 μm and a large amplification ratio of 21.4. The microgripper is capable of multiscale micromanipulation.

https://iopscience.iop.org/article/10.1088/0964-1726/24/7/075031/pdf

A new piezo-driven microgripper based on the double-rocker mechanism

Piezoelectric bimorphs have been used as a micro-gripper in many applications, but the system might be complex and the response performance might not have been fully characterized. In this study the dynamic characteristics of bending piezoelectric bimorphs actuators were theoretically and experimentally investigated for micro-gripping applications in terms of deflection along the length, transient response, and frequency response with varying driving voltages and driving signals. In addition, the implementation of a parallel micro-gripper using bending piezoelectric bimorphs was presented. Both fingers were actuated separately to perform mini object handling. The bending piezoelectric bimorphs were fixed as cantilevers and individually driven using a high voltage amplifier and the bimorph deflection was measured using a non contact proximity sensor attached at the tip of one finger. The micro-gripper could perform precise micro-manipulation tasks and could handle objects down to 50 µm in size. This eliminates the need for external actuator extension of the microgripper as the grasping action was achieved directly with the piezoelectric bimorph, thus minimizing the weight and the complexity of the micro-gripper.

https://www.mdpi.com/1424-8220/13/5/5826/pdf

Ahmed Abo-Ismail

Papers

Development of a micro-gripper using piezoelectric bimorphs.