A novel magnetic shape memory-based linear actuator with strain wave motion transmission

This paper presents the design, fabrication, and experimental validation of a novel actuator type: strain wave gearing magnetic shape memory (SWG-MSM) linear actuator. The actuator employs four individually controlled MSM elements driven by a multi-phase magnetic circuit to convert MSM elongation into continuous long-range motion through a strain wave gearing. A prototype was constructed to evaluate the performance of this concept and to compare experimental results with model-based predictions. The device achieved a maximum output velocity of 28.4 mm/s at 50 Hz and a maximum force of 2.8 N, closely matching simulation results. The experimentally verified operational bandwidth of approximately 50 Hz corresponds well to the predicted dynamic limits, with discrepancies mainly attributed to non-stabilized MSM material variability, presence of multiple twin boundaries, and mechanical backlash. The experiments confirmed that the designed circuit provides sufficient actuation bandwidth while maintaining low magnetic crosstalk between phases. The results demonstrate the feasibility of SWG-MSM actuation and validate key performance characteristics predicted by the underlying model. The study identifies the primary factors limiting performance and outlines directions for further optimization towards practical high-precision MSM-based actuators.