Review of MSM Actuators: Applications, Challenges, and Potential

Magnetic shape memory alloys (MSMAs) are a new and rapidly developing class of smart materials. These alloys demonstrate significant strain (from
6%
to
12%
) under an external magnetic field, which combined with their wide actuation frequency range, rapid accelerations, and high energy efficiency has resulted in MSMAs being used in a wide range of applications, for example, for energy harvesting, in measurement devices, flow control and pump applications, and as actuators and dampers. MSM actuators inherit the properties of MSMAs and MSM actuators can thus be extremely useful in many areas such as robotics, mobile machines, aerospace engineering and medicine, to name a few. Although the volume of research related to MSM actuators has increased in recent years, only a few types of these actuators exist, and the number of possible applications is currently rather limited. Nevertheless, MSM actuators clearly have great potential. Against this background, this paper reviews the current state of MSMA technology, examines different classes of MSM actuators and their current applications, and presents opportunities that have not yet been properly explored.