Development of a microrobot-based micromanipulation cell in a scanning electron microscope (SEM)

In the scanning electron microscope (SEM), specially designed microrobots can act as a flexible assembly facility for prototype microsystems, as probing devices for in-situ tests in various applications or just as a helpful teleoperated tool for the SEM operator when examining a few samples. Several flexible microrobots of this kind have been developed and tested. Driven by piezoactuators, these few cubic centimeters small mobile robots perform manipulations with a precision of up to 20 nm and transport the gripped objects at speeds of up to 3 cm/s. New microrobot prototypes being employed in the SEM are described in this paper. The SEM's vacuum chamber has been equipped with various elements to enable the robots to operate. In order ot use the SEM image for automatic real-time control of the robots, the SEM's electron beam is actively controlled by a PC. The latter submits the images to the robots' control computer s ystem. For obtaining three- dimensional information in real time, a triangulation method with the luminescent spot of the SEM's electron beam is being investigated. Finally, the strategies of a micro force sensing and control methods required for handling techniques with two robots are discussed.