Millimeters-Stroke Nanopositioning Actuator With High Positioning and Thermal Stability

This paper presented the design and modeling of a novel nanopositioning actuator that delivers millimeters stroke with high positioning and thermal stability. This actuator comprises a unique electromagnetic driving module (EDM) articulated from a segmented dual-magnet (DM) configuration, and flexurebased supporting bearings realized via a flexible membrane concept. In this paper, the fundamental insights on how to design and model the proposed segmented DM configuration are presented in detail. The remainder of this paper focuses on the thermal modeling of the unique EDM and the stiffness modeling of the unconventional flexure-based bearings. Subsequently, all theoretical models are evaluated through experimental investigations conducted via a developed prototype. The prototype also achieved an average positioning stability of ±10 nm with a thermal stability of ±0.1°C throughout a traveling range of 2 mm (±1 mm). Such actuator is useful for applications where direct feedback on the end effector is impossible.