The systematic design and fabrication of a three-chopstick microgripper

Abstract

In this study, we constructed a new type of gripper for micron-sized objects using piezoelectric multi-layer benders. This new gripper is composed of three chopsticks: two are designed to grip micro-objects, and the third is used to help grasp and release the objects. It is well known that a micro-object is much easier to grasp than to release. Electrostatic, van der Waals forces and surface tension between the chopsticks and object are believed to be the main causes of adhesion. We introduced a third auxiliary chopstick to overcome these surface effects and to reduce the electrostatic forces between the object and chopsticks. All three chopsticks were made of tungsten wires with ends sharpened by etching, which minimises the van der Waals effect. We constructed a three-chopstick gripper for micro-objects and tested its functionality by holding and releasing a 100-micron diameter object. The experiment showed that the third auxiliary chopstick functions effectively.