Actuating MSM Alloy With Motionless Drive

Ni-Mn-Ga is a Magnetic Shape Memory (MSM) alloy, which shape changes when either a mechanical stress or magnetic field is applied. By manipulating the magnetic field to sweep across an MSM element, the field causes a small pocket to form in the element and move with the magnetic field. This mechanism can be used to make a micropump. Such a pump was designed to have a rotating magnet driven by an electric motor to control the magnetic field. Here, we present a motionless drive system consisting of electromagnetic poles located on both sides of the MSM element along with the appropriate electrical switches to pulse the magnetic field. We have simulated this device with the simulation tool ANSYS. We further built a prototype device and measured the magnetic field as a function of pole pitch and pole symmetry. Simulation from ANSYS verified that the magnetic field can move to translate twinned region from start to end. We next propose to insert an MSM element into the motionless drive to validate simulation and performance