This paper presents experimental and simulation results on the performance of a new kind of linear actuator making use of the magnetic shape memory (MSM) effect. The actuation material is a Ni-Mn-Ga foil of 200 μm thickness that has been fabricated from a bulk Ni-Mn-Ga (100) single crystal consisting of 10 M martensite variants at room temperature. Stress-strain experiments on tensile test structures demonstrate that the stress needed for reorientation of martensite variants is about 1.2 MPa. The low twinning stress allows magnetic-field induced variant switching, the basic mechanism of MSM actuation. A Ni-Mn-Ga foil actuator is fabricated by lithography and hybrid integration. The actuator shows a maximum magneto strain of 4.9%, which is limited by the constraints of fixation and loading. Upon tensile loading at 1.5 MPa, linear actuation cycles are generated with an actuation stroke of 2.2%. The linear actuator is used as a benchmark system for modeling the coupled magneto-mechanical behavior of MSM actuation. We present finite element simulations based on a thermodynamic Gibbs free energy model that describes the observed tensile stress-dependence of magneto strain in many respects.

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