Bacteria are known to adhere to surfaces, which allows for the formation of biofilms, possibly causing a surge in hospital-offset infections, perilous diseases, and in some cases, death. Although certain bacteria are present in the natural flora of the human skin, some present extreme clinical significance due to the ability to transmit and adhere, and can be resistant to antibiotics. They also evolve over time to survive in harsh environmental conditions. Current research reveals that design of plastic surfaces containing submicron structures, is becoming a popular approach to tackle issues concerning infection transmission, with inspiration being derived from biomimetics and self-cleaning surfaces, such as the surface of a gecko skin, and the hydrophobic wax layer of forest leaves. Main barriers to adoption include that these surfaces alone are difficult to manufacture on 3D products, expensive to fabricate on a large scale and do not last long when subjected to environmental wear. Replication of nano-scale ridges was carried out using micro-injection, and the various samples were characterised using a range of tools to determine physical and biomechanical parameters. The sample surfaces were then cultured with the pathogenic bacterium Staphylococcus aureus under several environmental conditions, and the results were statistically analysed to reveal that anti-fouling LIPSS (laser induced periodic surface structures) ridges perform better to reduce bacteria cell-substrate adhesion, when compared to flat surfaces, or surfaces containing dual structures (anti-fouling ridges combined with anti-wear walls). It was therefore demonstrated that nanotextured polymeric surfaces with hydrophobic characteristics have exceptional non-fouling properties, preventing S. aureus, a very significant bacterial strain, from initial adhesion, a critical primary mechanism in its ability to proliferate. Collectively, the findings of this study strongly support the literature, suggesting that the bacteria struggle to adhere onto polymeric topography with increased water contact angles and simple nanostructures. However, the addition of certain anti-wear micro-features increased bacterial adhesion, reducing the efficacy of the non-fouling nanostructures from preventing biofilm formation.

Afin de convertir un maillage triangulaire en une surface spline de CAGD/CAM, cette thèse adresse l’un des problèmes les plus cruciaux du processus de conversion : extraire un “bon” maillage de contrôle quadrilatéral de la surface. Ce que nous entendons par “bon” est que les arêtes du maillage de contrôle se croisent perpendiculairement et sont alignées avec les principales directions de la courbure de la surface. Ces deux propriétés du maillage de contrôle permettent de fournir une bonne approximation de la surface avec peu de points de contrôles. D’ailleurs, ils aident considérablement à réduire des oscillations non désirées sur la surface spline finale. Pour résoudre ce problème, nous proposons un nouvel algorithme automatique, appelé paramétrisation globale périodique. L’idée fondamentale de cet algorithme est de trouver une paramétrisation qui ait un “sens d’un point de vue géométrique”, pour ce faire, elle doit être guidée par la courbure de la surface, représentée par une paire de champs de direction orthogonaux. Les iso-lignes de cette paramétrisation sont ensuite extraites pour définir un maillage de contrôle qui ait les propriétés requises. Ce maillage de contrôle, nous permet de construire une approximation en surface T-spline de la surface triangulée initiale. Nous exposons plusieurs résultats de cette conversion d’un maillage triangulée en surface spline. Les résultats montrent que, grâce aux maillages de contrôle anisotropes, les surfaces spline finales ont beaucoup moins d’oscillations que celles construites par les méthodes précédentes qui ne tiennent pas compte de l’anisotropie de la surface / Aiming at converting a triangular mesh into a CAGD/CAM spline surface, this thesis focuses on one of the most crucial problems of the conversion process, i.e. extracting a “good” quadrilateral control mesh of the surface. What we mean by good is that the edges of the control mesh should be orthogonal and aligned with the principal directions of curvature of the surface. These two properties make the control mesh optimum in an approximation point of view, and greatly help to reduce unwanted oscillations on the final spline surface built from it. To solve this problem, we propose a new automatic algorithm, called periodic global parameterization. The basic idea is to find a “geometry-meaningful” parameterization guided by a pair of orthogonal anisotropic direction fields. Then, the iso-value lines of this parameterization will be extracted to define an initial control mesh, that satisfies the two criteria of a good control mesh. With the initial control mesh, we explain how to construct a T-spline approximation of the initial triangulated surface. We show several examples of the triangular mesh to T-spline conversion. The results show that thanks to the anisotropic control meshes, the final spline surfaces generated have much less oscillations as compared to results of previous methods, that do not take into account of the anisotropy

Now a days. additive Manufacturing is becoming a major part of the manufacturing industries all around the world. Even, it is still a developing field.Its main advantage is its ability to print different types of shapes, in different sizesand good quality. The additive manufacturing technologies is capable of bring down the costs of the manufacturing when compared to other traditional methodsof manufacturing. This technology gives the flexibility to making complex shapesaccording to the clients and customers requirements also this technology canreduce time and human effort/involvement needed in the manufacturing industries. Now 3D printing has more influence in Swedish market more than ever and thisthesis is a part of a project of DiSAM – Digitalization of supply chain in Swedish Additive Manufacturing to implement 3D Printing into Swedish market. This thesis describe how advance materials and new manufacturingtechnologies can play a very important role in building the future and from thisstudy we are trying to find out whether the additive manufacturing technology can replace the traditional manufacturing process like injection molding. The main aim of the thesis is to design and fabricate a simple mould geometry for producing Silicone Rubber products using additive manufacturing and to assess the quality ofthe obtained product in terms of surface topography. Our project partner UnimerPlast & Gummi AB who is a major producer of plastics and rubber products is facing a problem in the production of silicone rubber products. They want to produce a mould for producing silicone rubber products using additivemanufacturing. In this thesis we had made the study in two parts, a design part and ananalysis part. In the design part we sorted out one material which is suitable for our application that is to produce a mould for making silicone products while in analysis part we made a study about the surface topology and its quality to see whether 3D printed moulds could produce silicone rubber products with same or better surface quality than the one which are produced using conventional injection moulding process. As a result of our study we came to know that high temperature resin can be used for making moulds to produce silicone products and only factor affecting the quality of the surface of mould or silicone product is built orientation and other factors like layer thickness, curing temperature and time does not have any impact on the surface quality.

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