Operation principle and design of a differential magnetic shape memory actuator

Magnetically controlled shape memory alloy (MSMA) exhibits large, reversible strains in the presence of a sufficiently high magnetic field, which provides a new way to produce motion and force. In this paper, the magnetic control properties of MSMA, the operation principle, design and control method of a differential MSMA actuator are introduced. In compare with the conventional MSMA actuator design, the proposed differential MSMA actuator can compensate the temperature influence, reduce the excitation power and improve the accuracy of position control as well as the dynamic behavior. The validity and feasibility of the proposed structure and control strategy have been examined by the tested results of a prototype differential MSMA actuator.