Thermal cycling effect on a shape memory and piezoelectric heterostructure

Many researches have been developed from combination of various materials to obtain a new material that presents different properties. These combinations form hybrid structures or heterostructures with similar characteristics to the starting materials. In this work, it is presented an experimental study about a heterostructure composed by NiTi Shape Memory Alloy (SMA) and Lead Zirconate Titanate piezoelectric (PZT). The study shows the SMA thermal behavior based on the coupled PZT electrical behavior, when subjected to thermal cycles. Some authors classify PZT and SMA as smart materials because they express reactions when they are subjected to an external energy. Piezoelectric material produces an electric field on its surface when subjected to mechanical strain and it is deformed when subjected to an electric field. SMA materials react to changes in the shape or mechanical stiffness when subjected to heat. Thus, PZT can be classified as an electromechanical material and SMA as a thermomechanical material. In this case, with the mechanical coupling between these two materials is possible to determine the thermal behavior of SMA by varying the electric field on the PZT. An experimental structure was designed to obtain the results. The outcome of SMA thermal behavior is shown as a function of varying the voltage on the PZT.