3. Shape memory alloy (SMA) actuation

3.1 Basic principle

Shape memory alloys (SMAs) were discovered over 80 years ago. They were first used in industry in the 1970s in the form of fastening sleeves for avionics. Since then, their use has spread to many fields, particularly nickel- and titanium-based alloys. These are exploited for three of their specific thermomechanical properties: hyperelasticity in the austenite state, plastic behavior in the martensite state and shape memory effect controlled by temperature change.

The field of robotics has also been using AMF actuators for many years. Recent robotics applications such as microrobotics, space robotics and medical robotics call for actuators that are not only increasingly efficient, but also easier to integrate into highly congested systems,...