Characterisation of 100 µm Diameter Shape Memory Alloy Actuators for Cyclic Applications

Abstract

In this paper, the actuation behaviour of two commercially available shape memory alloy (SMA) actuators known as Flexinol and Biometal both having diameter of 100 µm is investigated under cyclic loading conditions. An experimental test rig was used to characterise the Nickel-Titanium (NiTi) based SMA actuators. Three different actuation voltages, 4.5 V, 5 V, 5.5 V, were used. The length of stroke and drift over one hundred cycles were measured for both types of actuators. The results showed that a higher actuation voltage result in higher length of stroke. Similarly, larger drift was observed for higher voltages. It was also found from the experimental results that Biometal actuators underwent larger drift than Flexinol actuators, this showed weaker resistance to permanent deformation for the former. It has been found from this research that Flexional actuators having diameters of 100 µm produced larger stroke and smaller drift than Biometal actuators under similar cyclic actuation conditions.