Percorrer por autor "Faria, Carlos"
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- Applications and properties of PDMS: From biomicrofluidics to transparent face masksPublication . Lima, Rui A.; Maia, Renata; Souza, Andrews; Barbosa, Filipe; Carvalho, Denise; Carvalho, Violeta; Neves, Lucas B.; Faria, Carlos; Miranda, Inês; Sousa, Paulo; Zille, Andrea; Teixeira, Senhorinha; Minas, Graça; Machado, Lúcio; Ribeiro, J.E.Polydimethylsiloxane (PDMS) is a versatile silicone elastomer widely used in biomedical engineering due to its exceptional properties, including flexibility, chemical stability, optical transparency, biocompatibility, and ease of manufacturing. This chapter explores the unique characteristics of PDMS and its applications in biomicrofluidics and sustainable product development. PDMS is a hyperelastic material with excellent optical transparency, thermal stability, and gas permeability, making it ideal for various applications such as microfluidics, biomodels, blood analogues, implants, and organs-on-chip platforms. Its biocompatibility minimizes adverse tissue reactions, making it suitable for medical implants and skin treatments. However, its hydrophobic nature can limit certain applications, particularly in bioflow transport phenomena. To address this, surface modification techniques, such as oxygen plasma treatment, have been developed to enhance its wettability and expand its usability. In biomicrofluidics, PDMS is extensively used to create microfluidic devices that study blood cell deformability, aiding in the diagnosis of diseases like cancer, diabetes, and malaria. These devices, featuring contractions and bifurcations, provide valuable insights into microscale blood rheology and flow phenomena, improving our understanding of blood flow behavior and validating numerical simulations. The chapter also highlights the innovative use of PDMS in the production of sustainable transparent face masks. By incorporating recycled PDMS and textile fabrics, these masks feature a transparent window that allows visibility of the user’s lips, making them ideal for individuals who rely on lip-reading. The masks meet European Directive EN 14683:2019 standards, achieving level 2 certification for general public use. They offer excellent breathability, bacterial filtration efficiency, and optical transparency, while also promoting sustainability by reusing PDMS at the end of its life cycle. In conclusion, PDMS is a highly adaptable material with significant potential in biomedical applications and sustainable product development. Despite its hydrophobic nature, advancements in surface modification techniques continue to enhance its functionality, making it a valuable resource for innovative solutions in healthcare and beyond.
- Path generation, control, and monitoringPublication . Faria, Carlos; Martins, Daniela A.L.; Matos, Marina A.; Pinho, Diana; Ramos, Bruna; Bicho, Estela; Costa, Lino; Espirito Santo, Isabel; Fonseca, Jaime; Monteiro, M. Teresa T.; Pereira, Ana I.; Rocha, Ana Maria A.C.; Vaz, A. Ismael F.A critical issue in additive manufacturing (AM) is the control of the printer actuators such that the deposition of material (or a few different materials) takes place in an organized way. Typically, the actuators are connected with a low-level controller that can receive computer numerical control (CNC) instruction. A 3D printer controller is, usually, expected to receive a set of CNC instructions in a format called G-Code, where a set of control instructions is provided. These instructions include the necessary settings for the printer to work (e.g., a temperature setup) and printer head movement instructions (e.g., the x-, y-, and z- positions in reference axes). The set of the printer actuators positions, where some operations take place, is called the printer path. Path planning or generation corresponds to the computation of the printer head trajectory during a period of time where the object is to be built. A five-degree of freedom/5-axis 3D printer that considers a hybrid process based on additive manufacturing of composites with long or short fibers reinforced thermoplastic matrix is being addressed in this book.
- Progress in Nanofluid Technology: From Conventional to Green Nanofluids for Biomedical, Heat Transfer, and Machining ApplicationsPublication . Cardoso, Beatriz D.; Souza, Andrews; Nobrega, Glauco; Afonso, Inês Santos ; Neves, Lucas B.; Faria, Carlos; Ribeiro, J.E.; Lima, Rui A.Nanofluids (NFs), consisting of nanoparticles (NPs) suspended in base fluids, have attracted growing interest due to their superior physicochemical properties and multifunctional potential. In this review, conventional and green NF technology aspects, including synthesis routes, formulation, and applications, are discussed. Conventional NFs, involving NPs synthesized using physical and chemical approaches, have improved NP morphology control but are likely to cause environmental and safety concerns. In contrast, green NFs that are plant extract, microorganism, and biogenic waste-based represent a sustainable and biocompatible alternative. The effect of key parameters (e.g., NP size, shape, concentration, dispersion stability, and base fluid properties) on the performance of NFs is critically examined. The review also covers potential applications: in biomedical engineering (e.g., drug delivery, imaging, theranostics, and antimicrobial therapies), in heat transfer (e.g., solar collectors, cooling electronics, nuclear reactors), and precision machining (e.g., lubricants and coolants). Comparative insights regarding green versus conventionally prepared NFs are provided concerning their toxicity, environmental impact, scalability, and functional performance across various applications. Overall, this review highlights the new promise of both green and conventional NFs and provides key opportunities and challenges to guide future developments in this field.