Nowadays it is the current technological advances what pushes forward the limits of applied scientific research, being this even more emphasized in materials science research. In particular, active materials have become an attractive field of study, both from the fundamental point of view of their peculiar structures and properties, and from the applications in new products, where industry constantly requires the implementation of new materials to improve their performances. Among active materials, a particular class of them is attracting the attention of excellence research over the last decades: the so-called Shape Memory Alloys (SMAs). These materials are metal alloys that undergo phase transitions (resulting in large mechanical deformations) induced by changing the temperature and/or applying a stress on them. The phenomenon of the transformation itself is known as the shape memory effect and relies on the Martensitic Transformation. This transformation is accompanied by large recoverable strains, as the material will recover its original form by the application of the pertinent stimulus (temperature or stress). This makes the SMAs perfect candidates for a wide variety of applications ranging from bioengineering or biomedical actuators, to their implementation in a number of industries such as robotics, aerospace or automotive. Magnetic SMAs present a large magnetic-field-induced strain (MFIS), where the application of a magnetic field deforms the material: these are the so-called Magnetic Shape Memory Alloys (MSMAs). Hence, the actuation of the material can be produced also upon the application of a magnetic field, being a contactless reaction, and that the response happens in the milliseconds timescale. Well-known typical MSMA alloys are Ni2MnGa and non-stoichiometric derived compounds, presenting deformations up to 10% of their dimensions upon the application of moderate magnetic fields in the range of few kG.
The SASPAT project presents two main goals: (a) to train the talented young researcher Dr. Jose M. Porro, in the attractive growing field of Magnetic Shape Memory Alloys (MSMAs), where the host and partner institutions have developed their expertise and knowledge; and (b) the design, development and optimisation of smart patterned MSMA surfaces for applications in industrial sectors such as microfluidics and optical microswitching. The aim of the project is to exploit the effect of the martensitic transformation on the patterned MSMAs to fabricate tunable smart surfaces. The training program includes learning the processes for growing single crystals and epitaxial thin films made of MSMAs, the patterning of the surfaces using top-down and bottom-up lithography techniques, and the structural and magnetic characterization of the patterned surfaces to explore and optimize their optical response and wettability upon the application of the corresponding stimulus.
