Self-Sensing Actuators Based on Ferromagnetic Shape Memory Alloys

Ferromagnetic shape memory alloys (FSMA) exhibit a strong magneto-mechanical coupling, which motivates their application in electro-mechanical actuators. The significant magnetic anisotropy causing the coupling can also be used for sensing. The application of both mechanism within one device form a so called self-sensing actuator. However, sensing in presence of an actuation magnetic field has not been investigated much in detail. The present study conveys the potential of different self-sensing concepts within FSMA actuators by means of simulation models, assuming typical properties and magnetic circuit topologies. Results are evaluated and the potential for practical assemblies of self-sensing FSMA actuators is discussed.