Actuation in microsystems: problem field overview and practical example of the piezoelectric robot for handling of microobjects

Microsystems, and in particular microrobots, require the development of new advanced actuators with very small dimensions, simple mechanical construction and high reliability. This paper presents an overview on the problem field of the microactuation and various kinds of actuation principles referring to the use of microrobots. To provide a microrobot with both the transportation and micromanipulation capabilities, various designs of piezoelectric actuators can be used. The piezoelectric robot for handling of microobjects (PROHAM) is proposed. The robot is equipped with three piezoelectrically driven legs, whereby it can move at a speed of several mm/sec. A manipulation tool, e.g. needle, pipette, gripper or glue applicator, can be mounted onto the robot's platform. The tool is driven by piezoelectric effect as well, and movements with an accuracy of 10 nm are possible. This allows the manipulation of very small objects under a microscope. The PROHAM can be used e.g. for the manipulation of biological cells, microassembly or testing of silicon chips.