A Compact Ultralinear Compliant Torsion-Reinforced Sarrus Mechanism

Abstract

In this study, a promising design for a compact compliant torsion-reinforced Sarrus mechanism (CORS) capable of achieving ultralinear motion is presented. The CORS prototype, made entirely of aluminum, is produced monolithically using electric discharge machining (EDM). The design incorporates four torsion-reinforced folded leaf springs that together function as a flexural mechanism. This design effectively reduces parasitic motion while improving support stiffness. To meet the specified requirements, a design optimization process is undertaken, carefully considering constraints, to attain an optimal CORS configuration. Integration of the CORS with a voice coil actuator and confocal chromatic sensors is carried out to detect parasitic motion. Experimental validation demonstrates that the CORS outperforms existing designs in terms of build volume, manufacturability, and scalability, and has parasitic translations of around 10 nm and parasitic rotations of around 5 μrad over the critical region of the range of motion.