A large-stroke planar MEMS-based stage with integrated feedback

Micro-electromechanical systems (MEMS) are all around us nowadays, especially in sensor technology. MEMS-based positioning stages can become favorable in applications where the available volume is small, the response needs to be fast, and the fabrication costs low. This thesis describes the development of such a positioning stage. Single degree-of-freedom (DOF) electrostatic actuators are used to apply a force to a shuttle that is constrained to move over a straight line by a flexure mechanism. The position of the shuttle is measured by using an integrated sensor. The operating principle of this sensor is the conductive heat transfer through air of a resistively heated silicon beam towards the actuated shuttle parallel to the heated beam. Closed-loop position control of the shuttle using the integrated sensor is demonstrated. Three single DOF shuttles are coupled to form a parallel kinematic 3DOF stage for in-plane motion. The 3DOF stage was designed, fabricated, and validated to have a large range of motion compared to existing stages. The complete stage is integrated in the device layer of a SOI-wafer, which means no assembly if required and the stage can be fabricated using only a single mask.