SMA Actuators: A Viable Practical Technology

SMA has evolved to become a viable and practical actuator technology. This paper presents a detailed assessment of this technology’s present status in terms of SMA maturity, ease of design and implementation, and current use. Topics covered include fundamental properties of SMA that contribute to it being a viable actuator technology, the pros and cons of its use as an actuator, elements of an SMA actuator system, rules of thumb for design and effective use, design guidelines/constraints, commercial in-product uses, and future directions and areas of desirable development. Among salient conclusions are that qualified actuator grade SMA exists, is being produced in volume, and is in current commercial use as a viable actuator technology in dozens of applications. However, current design tools are limited and thus successfully and efficiently creating an SMA actuated device still requires expert knowledge being much more difficult than it might first appear.