Microassembly Experiments With Transparent Electrostatic Gripper Under Optical and Vision-Based Control

This paper describes the assembly experiments conducted with a novel miniature assembly cell for microelectromechanical systems. The cell utilizes a novel transparent electrostatic gripper and uses several disparate sensing modalities for position control: computer vision for part alignment with respect to the gripper, a fiber-coupled laser, and a position-sensitive detector for part to assembly alignment. The assembly experiments performed indicate that the gripping force and stage positioning accuracy of the gripper are sufficient for insertion of micromachined parts into slots etched in silicon substrates. Details of the cell operation, the control algorithm used, and their limitations are also provided. Potential applications of the developed assembly cell are assembly of miniature optical systems, integration of optoelectronics, such as laser diodes with CMOS, and epitaxial lift-off of thin films used in optoelectronic devices.