A review of rotary actuators based on shape memory alloys

International audience; The development of rotary actuators is an important issue of the engineering applications of shape memory alloys (SMAs). This paper reviews about a hundred references on this topic, and presents around eighty actuators driven by SMAs. A classification is made according to the type of rotation (continuous or non-continuous), the single or reversible direction of the rotation, as well as the number of SMA elements involved in the device. Different issues are then discussed, such as the characteristics of the SMA elements, the heating and cooling system for the SMA, the control of the actuator, as well as the output torque and stroke which can be reached. This paper provides the first review focused on rotary actuators triggered by SMAs, highlighting the specificities and potentialities of such actuators for new applications in the future.