Fabrication of an electrothermally actuated electrostatic microgripper

A novel electrostatic microgripper, which can handle micro objects with the electrostatic force, is designed and fabricated. It consists of gripping part with one inner and two outer electrodes, and releasing part with an electrothermal actuator. It grips micro objects using electric field generated between the electrodes, and releases them using the backward motion of inner electrode with electrothermal actuation. The backward motion of inner electrode breaks the electric field and rapidly reduces the remaining charges of objects. The graspless work shows the safe object handling method and also suggests the solution for the releasing problem. The microgrippers are fabricated with 20 /spl mu/m and 40 /spl mu/m thick SOI wafers, and they successfully grip glass beads with 170 /spl mu/m diameter at 250 V and 100 V, respectively.