Desenvolvimento de compósito responsivo à base de PDMS, NiTi e cílios artificiais magnéticos para uso na robótica mole

Abstract

The increase in the average age of the global population drives new efforts in materials engineering to develop devices that facilitate and assist human activities. In this context, soft robotics aims to create devices and sensors capable of generating movements and forces, mimicking the dexterity and deformability found in organic entities such as human skin or octopus' arms. One of the major challenges in this field is the unavailability of lightweight systems with high mobility and control. To address the deficiency of materials that are insufficient in some of the established functions, the creation of responsive composites is necessary, thus combining the flexibility of one material with the controllability of another. Based on this, this work aimed to develop a composite based on polydimethylsiloxane (PDMS) reinforced with a nickel-titanium shape memory alloy (NiTi), exhibiting thermally responsive actuation and containing artificially generated cilia enriched with Fe, enabling magnetically responsive actuation in a bioinspired structure. The NiTi alloy, in wire and ribbon forms, activated to perform thermally induced shape memory movement, was embedded in the silicone, forming a flexible actuator and providing controlled stiffness. Fe, in turn, was incorporated through physical vapor deposition by magnetron sputtering via two routes: deposition on quartz (SiO2) for aggregation on the cilia and direct deposition on the cilia. To understand the design of the responsive composite, physical-chemical characterization techniques such as FTIR, DSC, tensile testing, mechanical simulation, SEM, magnetometry, among others, were performed. This thesis presents a literature review covering the relevant topics for the practical realization of the work, the current state-of-the-art, the methodology used, and the results obtained. From the initially generated hypothesis, it was concluded that NiTi is an interesting reinforcement for generating controlled rigidity and can be incorporated into compliant structures, providing appropriate mobility. The magnetron sputtering technique is also a strong ally in the envisioned applications, such as soft robotics, providing the necessary surface modification on various substrates, whether in powder form or solid compliant materials. The future of this study is promising, as is the range of applications that can benefit from the synergistic effect of thermally tunable stiffness and controlled actuation through the application of an external magnetic field. [resumo fornecido pelo autor]