Design and Assessment of a Micropositioning System Driven by Electromagnetic Actuators

In this paper, a parallel-kinematics-based micropositioning system prototype driven with four electromagnetic motors is presented. The optimal design characteristics of the system incorporate its long-range displacement capability with submicrometer level positioning precision suitable for numerous microapplications. In order to achieve a compact design with micrometer level component assembly tolerances, the movable mechanical structure of the experimental prototype has been microfabricated in the silicon material using inductively coupled plasma etching process. The 80 mm × 80 mm footprint of the prototype is able to perform millimeter level displacement strokes along both axes in the horizontal plane. The experimental results demonstrate that the micropositioning system is capable of delivering variable strokes up to 2.5 mm in the xy-plane. In closed-loop control the system is able to perform repeatable displacement of 2 μm with a positioning precision of 24 nm. In addition, the proposed micropositioning system design is able to carry 17.3 g of additional load during planar motion in the xy-plane.