Unidade de Investigação - CDRsp – Centro para o Desenvolvimento Rápido e Sustentado de Produto
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Browsing Unidade de Investigação - CDRsp – Centro para o Desenvolvimento Rápido e Sustentado de Produto by Subject "3D printing"
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- 3D printed poly(E-caprolactone)/Hydroxyapatite scaffolds for bone tissue engineering: A comparative study on a Composite Preparation by Melt blending or solvent casting techniques and the influence of bioceramic content on scaffold propertiesPublication . Biscaia, Sara; Branquinho, Mariana V.; Alvites, Rui D.; Fonseca, Rita; Sousa, Ana Catarina; Pedrosa, Sílvia Santos; Caseiro, Ana R.; Guedes, Fernando; Patrício, Tatiana; Viana, Tânia; Mateus, Artur; Maurício, Ana C.; Alves, NunoBone tissue engineering has been developed in the past decades, with the engineering of bone substitutes on the vanguard of this regenerative approach. Polycaprolactone-based scaffolds are fairly applied for bone regeneration, and several composites have been incorporated so as to improve the scaffolds’ mechanical properties and tissue in-growth. In this study, hydroxyapatite is incorporated on polycaprolactone-based scaffolds at two different proportions, 80:20 and 60:40. Scaffolds are produced with two different blending methods, solvent casting and melt blending. The prepared composites are 3D printed through an extrusion-based technique and further investigated with regard to their chemical, thermal, morphological, and mechanical characteristics. In vitro cytocompatibility and osteogenic differentiation was also assessed with human dental pulp stem/stromal cells. The results show the melt-blending-derived scaffolds to present more promising mechanical properties, along with the incorporation of hydroxyapatite. The latter is also related to an increase in osteogenic activity and promotion. Overall, this study suggests polycaprolactone/hydroxyapatite scaffolds to be promising candidates for bone tissue engineering, particularly when produced by the MB method.
- Additive manufactured stoneware fired in microwave furnacePublication . Santos, Tiago; Ramani, Melinda; Devesa, Susana; Batista, Catarina; Franco, Margarida; Duarte, Isabel; Costa, Luís; Ferreira, Nelson; Alves, Nuno; Pascoal-Faria, PaulaAdditive manufacturing (AM) techniques have revolutionized the concept of building parts not only in laboratory contexts but also in industry environments and can be applied to distinct fields such as the health, automotive and aeronautics sectors [...]
- Design of a Video Otoscope Prototype with an Integrated Scanner for Hearing Aid Direct Digital Manufacturing: A Preliminary StudyPublication . Ganhão, Francisco; Santos, António Carvalho; Silva, Carla; Monteiro de Moura, Carla SofiaIn the current landscape of hearing rehabilitation, ear mold manufacturing typically involves the injection of silicone into the external ear canal (EEC) of each patient. This invasive procedure poses several risks, including the potential for silicone residue retention and tympanic membrane perforation, which may necessitate surgical intervention. To mitigate these risks, we present the design of a video otoscope that integrates a scanner capable of capturing high-precision, real-time images of the EEC’s geometry. The developed device allows (i) the generation of a 3D CAD model leading to the direct, quick, and low-cost production of customized hearing aids using 3D printing and (ii) the establishment of medical protocols for carrying out diagnoses and monitoring of hearing pathology evolution using methodologies based on Artificial Intelligence. Furthermore, the use of customized hearing aids that allow the application of Rhythmic Auditory Stimulation (RAS) and music therapy enhances audiology as an alternative and innovative way to treat cognitive and degenerative diseases, as well as pathological disorders.
- Experimental study on 3D printing of concrete with overhangsPublication . Brun, Francis; Gaspar, Florindo; Mateus, Artur; Vitorino, João; Diz, FranciscoThe construction industry has been receiving in the recent past years the 3D printing technology as an emerging technology. Several researchers and companies have been reporting a number of case studies that show the possibilities of this technology regarding the dimensions, shape, building time, finishing and the material characteristics. It is commonly accepted that one of the big advantages of 3D printing is its possibility regarding the shape of the printed object since it can be easily changed each time a new piece is printed. This possibility raises some challenges regarding the printing limits, that are needed to the project design, such as to create overhangs. In this sense, a work was carried out to evaluate and optimize concrete printing mixtures and assess the 3D concrete printing of elements with overhangs. This paper presents the work carried out, showing the optimization of mixture composition for the binder/aggregate ratio, cement/fly ash ratio, and amount of superplasticizer and hardening accelerator, and evaluating their printing performance and mechanical properties. Printing of overhangs was possible for angles with the vertical direction till 17.5º.
- Progress in Digital and Physical ManufacturingPublication . Almeida, Henrique A.; Vasco, Joel C.This book contains selected papers from the First International Conference on Progress in Digital and Physical Manufacturing (ProDPM'19), organized by the School of Technology and Management (ESTG) of the Polytechnic Institute of Leiria (IPL). It presents a significant contribution to the current advances in digital and physical manufacturing issues as it contains topical research in this field. The book content is of interest to those working on digital and physical manufacturing, promoting better links between the academia and the industry. The conference papers cover a wide range of important topics like biomanufacturing, advanced rapid prototyping technologies, rapid tooling and manufacturing, micro-fabrication, 3D CAD and data acquisition, and collaborative design.
- The Use of Polypropylene and High-Density Polyethylene on Cork Plastic Composites for Large Scale 3D PrintingPublication . Brites, Fernando; Malça, Cândida; Gaspar, F.; Horta, J. F.; Franco, M. C.; Biscaia, S.; Mateus, A.This work focuses on studying the possibility of 3D printing of composite materials composed by cork and a polymer matrix (CPC). Initially the cork was mixed with two types of polymers (HDPE and PP) in different proportions and later processed using extrusion and injection. The composites were tested to study the physical, chemical and mechanical properties. The material was then tested on a large-scale 3D printer to study its feasibility and the ability to produce new products through 3D printing. Attention was focused on the use of pure cork, varying the concentration of cork and coupling agent in thermoplastic matrix composites of PP and HDPE. It was demonstrated that the increase of 5wt.% of coupling agent in the two types of polymers significantly improved the mechanical properties and adhesion between the phases but the increase in cork concentration decreased mechanical properties and crystallinity. The CPCs with PP showed to have better mechanical properties, better aesthetic and internal structural quality, and easier processability than those with HDPE matrix. Nevertheless, the HDPE CPCs showed a high degree of crystallization. Concerning 3D printing, it was demonstrated the possibility of making new products based on natural cork fibers, showing promising results, although additional research is still needed to optimize the process.