In the present work, prototypes of polymeric cantilever-based magnetic microstructures were fabricated by means of stereolithography (SL). To this end, a UV-curable system suitable for high-resolution SL-processing was formulated by blending a bifunctional acrylic monomer with photoinitiator and visible dye whose content was tuned to tailor resin SL sensitivity. Subsequently, to confer ferromagnetic properties to the photopolymer, two different strategies were implemented. A two-step approach involved selective deposition of a metal layer on photopolymer SL-cured surfaces through an electroless plating process. On the other hand, SL-processable ferromagnetically responsive nanocomposites (FRCs) were obtained by directly loading magnetite nanoparticles within the photopolymer matrix. In order to achieve high-printing resolution, resin SL sensitivities were studied as a function of the various additives contents. Photocalorimetric analyses were also performed to investigate the photopolymer conversion efficiency upon light exposure. High-performing formulations were characterized by reduced penetration depth (<50 μm) and small critical energies thus enabling for fast printing of micrometric structures. Finally, the self-standing characteristics of the resin combined with the layered-fashion deposition typical of the 3D printing technologies were exploited for the fabrication of cantilever (CL)-based beams presented as possible magnetic sensors. As a demonstration of the feasibility of the two approaches, the magnetic beams were successfully actuated and their sensing performances in terms of static deflection vs applied magnetic field applied were qualitatively studied. Being not restricted to CL-based geometries, the combination of SL-printing with the formulation of novel smart photopolymers open the way toward the fabrication of high-customized complex 3D models integrating functional microstructures.

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In the present work, surface engineering of Ti6Al4V, produced via selective laser melting parts was carried out with the aim of investigating how surface features of substrate may improve the coupling with AlTiN coatings deposited by Physical Vapor Deposition 2 reactive High-Power Impulse Magnetron Sputtering. In particular, the work highlighted how vacuum thermal treatments at 800°C induced peculiar mesoscale morphology and surface chemical modifications of the Ti6Al4V, which contributed to improve the adhesion of the deposited AlTiN thin films. Chemical composition, crystallographic structure, and surface properties of both substrates and coatings were analyzed by Field Emission Scanning Electron Microscopy (equipped with Energy Dispersive Spectroscopy), Atomic Force Microscopy, X-ray Photoelectron Spectroscopy, X-Ray diffraction, nanoindentation, and scratch test measurements.