Self-aligning electrostatic gripper for assembly of millimeter-sized parts

In this study, the performance of several electrostatic grippers is evaluated. These grippers are designed to align millimeter scale parts to matching electrode geometry on the gripper surface. Friction between the gripper and part is overcome through ultrasonic excitation of the gripper by a piezoceramic element. The effect of different frequencies and amplitudes of excitation on alignment were observed. Additionally, the use of ultrasonic excitation to aid in part release after clamping was investigated. Under ideal conditions, part motion was most frequently observed in certain excitation frequency windows, which correspond to resonant modes of the part-gripper system.