Thermal cycling at constant stress for thin films over a wide temperature range: design and fabrication of a specific device for the study of microactuators

Abstract

The characterization of the mechanical behavior of shape memory thin film alloys is essential for their application as microactuators. Depending on the particular application, different elements has been considered for the fabrication of ternary NiTi-based alloys, in order to shift the martensitic transformation towards a lower or a higher temperature range. This work presents the design and implementation of a specific device to perform thermal cycles at constant stress on film-like samples over a wide temperature range, between -130 °C and 300 °C. The uniaxial stress application, the elongations and contractions measurements associated with the martensitic transformations and the cooling and heating methods are detailed in the present work. The fabrication and operation features of this relatively low cost device facilitates and promotes the study of shape memory thin films.