Investigation of minimal strokes of NiTi shape memory wires using laser activation

Abstract

Nickel-Titanium (NiTi) shape memory wires have established themselves in the actuator market (medicine, automotive industry, aerospace) because of their high power density and their simple activation by resistance heating. The actuator stroke, normally between 1 mm and 5 mm, can be adapted with control parameters (current, voltage, and duration). However, minimal strokes (< 100 µm) can only be achieved with a certain repeat accuracy since the spatially resolved resistance depends on material defects and also the fatigue state. In this study, actuator behavior when targeting for minimal strokes using laser activation is investigated.