Percorrer por autor "Sousa, Paulo"
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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.
- Patente Nacional Nº 117823 - Máscara facial, métodos para obtenção e utilização da mesmaPublication . Machado, Lúcio Manuel Machado; Soares, Delfim Fernandes; Faria, Carlos Alberto Jorge Leite; Minas, Graça Maria Henriques; Lima, Rui A.; Freitas, José Torcato Oliveira; Ribeiro, J.E.; Machado, Lúcio Manuel Alves; Freitas, Pedro Gil Novais; Gonzalez Abelleira, Lisardo Antonio; Areal, Clarisse Fernandes; Vilarinho, Maria Cândida Lobo Guerra; Carvalho, Joana Maria Freitas; Ribeiro, André José Pereira; Souza, Andrews Victor Almeida de; Sousa, Paulo; Teixeira, Senhorinha F.C.F.A presente divulgação refere-se a uma máscara facial compreendendo uma porção alongada para cobrir a face de um utilizador do nariz ao queixo e bochechas, e duas alças de orelha ligadas à porção alongada para fixar a referida porção alongada à face, em que a porção alongada compreende um filme transparente de polidimetilsiloxano (1).
- Properties and applications of PDMS for biomedical engineering: a reviewPublication . Miranda, Inês; Souza, Andrews Victor Almeida; Sousa, Paulo; Ribeiro, J.E.; Castanheira, Elisabete M.S.; Lima, Rui A.; Minas, GraçaPolydimethylsiloxane (PDMS) is an elastomer with excellent optical, electrical and mechanical properties, which makes it well-suitable for several applications such as microfluidic and pho-tonics in several areas. Due to its biocompatible feature, PDMS is widely used for biomedical purposes. This widespread led also to the massification of the soft-lithography technique, intro-duced for facilitating the rapid prototyping of micro and nanostructures using elastomeric ma-terials, most notably PDMS. This technique allowed advances on microfluidic, electronic and biomedical fields. In this review an overview of the PDMS properties and some of its commonly used treatments, aiming the suitability to those fields’ needs, are presented. Applications such as microchips in biomedical field, replication of cardiovascular flow and medical implants are also reviewed.