Superelastic Shape Memory Elements Using Intrinsic Sensor Effects

The superelastic effect of shape memory alloys (SMA) allows reversible material deformations of up to 8% of an element’s length. Although such SMA elements are commonly used for medical applications, only a few utilizations are used in the field of industrial automation. An often disregarded advantage of superelastic elements is the option to replace a conventional elastic element with a smart element including elastic characteristics as well as a deformation sensor. The resistance change of pseudoplastic and superelastic alloys in dependency of varying ambient temperatures, their characteristics during deformation and concepts for different elastic elements with intrinsic sensor functions are the topics of the paper at hand. Additionally, this paper offers an overview over possible combinations of both alloy types utilized as sensing elements. A demonstrator device, capable of elastic-deformation and sensor-feedback signals is presented at the end of this publication.