One of the greatest obstacles to clinical translation of bone tissue engineering is the inability to effectively and efficiently vascularise scaffolds. This limits the size of defects that can be repaired, as blood perfusion is necessary to provide nutrient and waste exchange to tissue at the core of scaffolds. The goal of this work was to systematically explore whether architecture, at a scale of hundreds of microns, can be used to direct the growth of microvessels into the core of scaffolds. A pipeline was developed for the production of hydroxyapatite surfaces with controlled architecture. Three batches of hydroxyapatite were used with two different particle morphologies and size distributions. On sintering, one batch remained phase pure and the other two batches were biphasic mixtures of α-tricalcium phosphate (α-TCP) and hydroxyapatite. Sample production methods based on slip casting of a hydroxyapatite-gelatin slurry were explored. The most successful of these involved the use of curable silicone to produce moulds of high-resolution, three dimensional (3D) printed parts with the desired design. Parts were dried and sintered to produce patterned surfaces with higher resolution than obtainable through conventional 3D printing techniques. Given the difficulties associated with the structural reproducibility of concave pores architectures in 3D reported in the literature, in this work, a 2.5D model has been developed that varies architectural parameters in a controlled manner. Six contrasting architectures consisting of semi-circular ridges and grooves were produced. Grooves and ridges were designed to have widths of 330 μm and 660 μm, with periodicities, respectively, of 1240 μm and 630 μm. Groove depth was varied between 150 μm and 585 μm. Co-cultures of endothelial cells and osteoblasts were optimised and used to grow microcapillary-like structures (referred to as "microvessels") on substrates. Literature shows that these precursors to microcapillaries contain lumina and can produce functional vasculature, demonstrating their clinical promise. The effects of the composition and surface texture of grooved samples on microvessel formation were studied. It was found that surface microtopography and phase purity (α-TCP content) did not affect microvessel formation. However, hydroxyapatite architecture was found to significantly affect microvessel location and orientation. Microvessels were found to form predominantly in grooves or between convexities. Two metrics - the degree of alignment (DOA) and the degree of containment (DOC) - were developed to measure the alignment of endothelial cell structures and their localisation in grooves. For all patterned samples, the CD31 (an endothelial cell marker) signal was at least 2.5 times higher along grooves versus perpendicular to grooves. In addition, the average signal was at least two times higher within grooves than outside grooves for all samples. Small deep grooves had the highest DOA and DOC (6.13 and 4.05 respectively), and individual, highly aligned microvessels were formed. An image analysis method that compares sample X-ray microtomography sections to original designs to quantify architectural distortion was developed. This method will serve as a useful tool for improvements to architectural control for future studies. This body of work shows the crucial influence of architecture on microvessel self-assembly at the hundreds of micron scale. It also highlights that microvessel formation has a relatively low sensitivity to phase composition and microtopography. These findings have important implications for the design of porous scaffolds and the refinement of fabrication technologies. While important results were shown for six preliminary architectures, this work represents a toolkit that can be applied to screen any 2.5D architecture for its angiogenic potential. This work has laid the foundations that will allow elucidating the precise correspondence between architecture and microvessel organisation, ultimately enabling the "engineering" of microvasculature by tuning local scaffold design to achieve desirable microvessel properties.

This thesis proposes an algorithm that determine the geometry of 3D-printed, custom-designed spring element bands made of thermoplastic elastomer (TPE) for use in a wearable orthotic device to aid in the physical therapy of a human hand exhibiting spasticity after stroke. Each finger of the hand is modeled as a mechanical system consisting of a triple-rod pendulum with nonlinear stiffness at each joint and forces applied at the attachment point of each flexor muscle. The system is assumed quasi-static, which leads to a torque balance between the flexor tendons in the hand, joint stiffness and the design force applied to the fingertip by the 3D-printed spring element. To better understand material properties of the spring element’s material, several tests are performed on TPE specimens printed with different infill geometries, including tensile tests and cyclic loading tests. The data and stress-strain curves for each geometry type are presented, which yield a nonlinear relationship between stress and strain as well as apparent hysteresis. Polynomial curves are used to fit the data, which allows for the band geometry to be designed. A hypothetical hand is presented along with how input measurements might be taken for the algorithm. The inputs are entered into the algorithm, and the geometry of the bands for each finger are generated. Results are discussed, and future work is noted, providing a means for the design of a customized orthotic device.

Modern 3D printing technology is becoming a more viable option for use in industrial manufacturing. As the speed and precision of rapid prototyping technology improves, so too must the 3D scanning and verification technology. Current 3D scanning technology (such as CT Scanners) produce the resolution needed for micron precision inspection. However, the method lacks in speed. Some scans can be multiple gigabytes in size taking several minutes to acquire and process. Especially in high volume manufacturing of 3D printed parts, such delays prohibit the widespread adaptation of 3D scanning technology for quality control. The limiting factors of current technology boil down to computational and processing power along with available sensor resolution and operational frequency. Realizing a 3D scanning system that produces micron precision results within a single minute promises to revolutionize the quality control industry. The specific 3D scanning method considered in this thesis utilizes a line profile triangulation sensor with high operational frequency, and a high-precision mechanical actuation apparatus for controlling the scan. By syncing the operational frequency of the sensor to the actuation velocity of the apparatus, a 3D point cloud is rapidly acquired. Processing of the data is then performed using MATLAB on contemporary computing hardware, which includes proper point cloud formatting and implementation of the Iterative Closest Point (ICP) algorithm for point cloud stitching. Theoretical and physical experiments are performed to demonstrate the validity of the method. The prototyped system is shown to produce multiple loosely-registered micron precision point clouds of a 3D printed object that are then stitched together to form a full point cloud representative of the original part. This prototype produces micron precision results in approximately 130 seconds, but the experiments illuminate upon the additional investments by which this time could be further reduced to approach the revolutionizing one-minute milestone.

Cette thèse porte sur l'évaluation de la réponse cellulaire in vitro vis-à-vis de différentes stratégies de modification de surface pour améliorer la capacité d’ostéointégration de céramiques bioinertes pour implants orthopédiques et dentaires. Premièrement des surfaces l'alumine-zircone avec différentes micro-rugosités obtenues par moulage par injection ont été étudiées. Le comportement d'ostéoblastes primaires humains (obtenus à partir de têtes de fémurs soumis à arthroplastie) a été étudié sur les surfaces telles quelles ou modifiées par traitement avec acide hydrofluorique. La micro-rugosité a eu seulement un effet mineur sur la réponse ostéoblastique tandis que la combinaison de micro- et nano-rugosité a eu un effet synergique sur la maturation ostéoblastique. Cette stratégie de modification de surface ouvre la voie vers des cupules acétabulaires céramiques monoblocs directement ostéo-intégrées. Deuxièmement, le robocasting (une technique d’impression 3D) a été exploré pour la production de structures macroporeuses en alumine-zircone avec une haute reproductibilité et contrôle architectural. Les structures imprimées ont présentées une topographie aux multiples niveaux grâce au design et les conditions de frittage. Les ostéoblastes ont pu s'attacher sur les structures 3D mais la préservation des cellules à l’intérieur des scaffolds sur le long terme reste à améliorer. Des techniques de sélection rapide de modifications de surface ont fait l'objet de la dernière partie de cette thèse. Deux différentes stratégies ont été utilisées sur la zircone: laser femtoseconde pour la production de multiples motifs sur un échantillon unique et échantillons avec un gradient de rugosité via le contrôle du temps d’attaque chimique. La morphologie des cellules souches humaines a permis d'avoir un indicateur précoce de la lignée de différentiation cellulaire. En conclusion, les différentes techniques de modification de surface de zircone et alumine-zircone utilisées à travers la thèse peuvent moduler l’interaction cellule-matériau en stimulant la différentiation ostéoblastique de cellules souches et la maturation des ostéoblastes. / The focus of this PhD thesis is the in vitro evaluation of cell-material interactions on bioinert ceramics with novel surface modifications for enhanced osseointegration of orthopaedic and dental implants. Firstly, alumina-zirconia surfaces with different micro-roughnesses obtained by injection moulding were studied. The behaviour of human primary osteoblasts (hObs) obtained from patients undergoing total hip replacements was studied on the different micro-rough ZTA surfaces and on combined micro-/nano-rough surfaces modified by hydrofluoric acid treatment. Micro-roughness alone had minor effects on hOb response while the combination micro-/nano-roughness induced a synergic effect on hOb maturation. This latter surface modification technique opens the way to the fabrication of ceramic acetabular cups with direct implantation capabilities. Secondly, robocasting (a 3D printing technique) was explored for the fabrication of a alumina-zirconia macroporous structures with high reproducibility and control of the architecture. Roughness at different scales was observed for the 3D structures due to the scaffold design and to the low temperature sintering conditions. Osteoblasts were able to attach on the 3D structures but cell retention at long term needs further optimization. Rapid screening of cell-material interactions was the subject of the last part of the thesis. Two different strategies were tested on zirconia: femtosecond laser to produce multiple patterns on a single sample and samples with a roughness gradient by the control of chemical etching time. Stem cell morphology was used as an early marker of cell differentiation lineage. In conclusion, the different surface modification techniques of zirconia and alumina-zirconia surfaces used in the thesis allow the modulation of cell-material interactions by stimulating stem cells osteogenesis and osteoblast maturation.

The construction of this thesis is developed from different conceptual interlacing axis that created a networking weave through which the field of investigation was debated and defined and a project of collaborative citizenship with the goal of providing an improvement in the social environment from which the visual impairment through art was built. Firstly, we speak about the context in which, in a dialogic way, the identity of Ph. D. Rosa Gratacós Masanella has grown and developed. With the help of the narrative research and the life story methods we make an approach to the life time experience of the main character of our investigation, in order to understand her social, political and educational context, how it relates to her personal life, her work as a professor and her artistic career, and how all these different perspectives have points in common. We also approach those people who met our protagonist, those who were her referents or were important in the evolution of her identity. We point Ph. D. Rosa Gratacós pioneer investigation in the field of visual impairment and we finally explain the multisensory project of The Senses Labyrinth, a project that was born from the idea of universal accessibility from the perspective of blind people. Sensory education, game and art become the source of teaching and learning for the researcher and they are applied together to art education and artistic perception from blindness, through service and learning methodologies / La construcció d’aquesta tesi es desenvolupa a partir de diferents eixos conceptuals que es van anar entrellaçant, configurant un entramat de networking a través del qual es va posar en conflicte, es va definir el mapa del territori de la investigació, i es va generar un projecte col•laboratiu de participació ciutadana amb l’objectiu d’aportar una millora qualitativa a l’entorn ciutadà a través de l’art i a partir de la discapacitat visual. En primer lloc, parlem del context en el que, de manera dialògica, creix i es desenvolupa la identitat de la Dra. Rosa Gratacós Masanella, a partir dels mètodes d’investigació narrativa i del relat de vida per reconstruir una aproximació a la seva historia de vida que permeti entendre el context social, polític i educatiu d’aquest trajecte vital en relació a la investigadora, a la seva pròpia experiència i al seu relat de vida, factors que coincideixen en alguns punts, com són la vessant artística, educativa i investigadora, amb més o menys distància i des d’on creix l’interès per l’estudi. També ens aproximem als subjectes que han tingut relació amb la protagonista com a referents i portes d’entrada al canvi i al desenvolupament de la pròpia identitat. Situem la investigació pionera de la Dra. Rosa Gratacós relacionada amb la discapacitat visual i finalment els eixos que han teixit tot el relat es cohesionen i es presenta el projecte multisensorial de La forma de les olors, que parteix de la idea d’accessibilitat universal, iniciada des de la discapacitat visual. L’educació sensorial, el joc i l’art esdevenen la font de l’ensenyament-aprenentatge de la investigadora i s’apliquen conjuntament a l’educació artística i a la investigació de la percepció artística des de la ceguesa, a través de metodologies d’aprenentatge i servei

於德語系國家提供3D列印積層製造技術之可行性分析 / ‘People can have the Ford Model T in any color – as long as it‘s black‘ (Henry Ford) In today’s competitive business environment, more is needed than building competitive advantages solely on cheap mass production on the other side of the globe. Product life cycles become shorter, customers more demanding, cost advantages of producing large amounts far from the distribution channels are eroding and flexibility in production is an essential parameter to meet customer’s demands. The purpose of this business plan is to show small and medium sized enterprises (SMEs) a possibility to conquer constrains of mass production by using one of the few real disruptive technologies of our times. 3D printing or additive manufacturing indeed has the potential to change the paradigm for manufacturing. In short, it is the process of building solid three-dimensional objects from any digital model data by applying materials usually layer upon layer. This method of building parts of virtually every shape is the reason for the name as opposed to subtractive or traditional manufacturing, where material is being removed by drilling, cutting, and milling. Additive manufacturing technologies can be used anywhere in the product life cycle from pre-production prototypes to full-scale production: On the entry level, small and medium sized enterprises could increase their performance through cost reduction by accelerating the business cycle. This is an implication of reduced time to market and improved product quality. The next level not only involves speed but also cost savings arising out of supply chain improvements. Additive manufacturing is able to significantly reduce required inventory and therefore is reducing working capital requirements. The third level takes full advantage of this new technology, exploiting the complexity for free phenomenon, which demonstrates that geometrically complex shapes can be produced at virtually no additional costs. Last but not least, while putting all the advantages of additive manufacturing, mass-customization of products becomes an available option even for smaller companies. The described paradigm shift already started, and although the industry is still small in absolute terms, growth rates have been impressive for the last few years. The global additive manufacturing market grew by 34.9% (CAGR) to US$ 3.07 billion in 2013, which is a continuation of the remarkable growth rates of 2010, 2011, and 2012. Even more exciting are the forecasts, which indicate that additive manufacturing could easily exceed US$ 21 billion by 2020. (cf. McKinsey Global Institute, 2013; Wohlers Associates Inc., 2014). The german speaking market is about 15% of the global additive manufacturing market with players being more educated in terms of additive manufacturing. Thus, it seems to be the right time to enter this market eager for innovation. This business plan proposes to set-up an additive manufacturing service provider in Austria, targeting the German speaking countries, and offering its services to mainly but not exclusively small and medium sized enterprises. Since the competition is existent but very segmented, the declared goal of 5% market share should be manageable in the first three years of operation. The main target clients are SME’s in the following fields: Manufacture of fabricated metal products and machinery and equipment Manufacture of motor vehicles, trailers, and semi-trailers Manufacture of furniture Manufacture of jewelry, bijouterie, and related articles Manufacture of medical and dental instruments and supplies 3magination, which is the proposed name for the company, shall provide the following services: Additive manufacturing education Design consultancy Material consultancy Small series production and prototyping However, the business model classifies the first three services as trust and relationship building investments and the company only charges for the production itself. 3magination disposes of metal and polymer processing printers and is able to produce a very large spectrum of objects. Design, material selection, and the flexible production itself are 3maginations’s declared competitive advantages. To ensure this path, a detailed analysis of key talents has been performed. Considering the conservative forecasts, initial investment of EUR 1.1 million in equity and a loan facility from banks of EUR 1.92 million would generate a NPV of EUR 25.5 million. Due to the large investments in fixed assets and the low sales volume at the beginning, a loss is anticipated in the first year. However, the company breaks even in the second year of operation and makes a small profit of EUR 286,394. From there on, the net income and sales ratio starts accelerating up to 34% in 2019.

Digital fabrication technologies such as 3D printers entail a radical change to the traditional consumer-producer paradigm. Combined with other recent developments, self-styled Makers design and fabricate sophisticated devices and interactive technologies that would otherwise never have existed. However, stopping the uninitiated novice from making use of this potential is complex CAD software, and a high barrier to entry. In this study a series of workshops explore the potential of combining traditional handicraft materials – such as clay, paper and fabric – with 3D scanning to enable novices to work with 3D printers. Based on the results a set of instruction were created detailing the process of making three types of practical objects, covering the entire process from the making and subsequent 3D scanning of a physical object, to the software clean-up and final 3D printing. The results suggest that whilst the explored method can enable novices to create 3D printable models, a certain mindset is required for the novice to do so effectively. / Innovation +

För att vi ska ha en förståelse av det förflutna måste arkeologer ha möjlighet att tolka arkeologiska fynd (Why Is Archaeology Important?, 2018). En typ av fynd är kilskrift. För att säkerställa bevaringen av denna typ av fynd har etiska principer etablerats som exempelvis inte låter någon utsätta fynden för fara ("Principles of Archaeological Ethics", 2018), till exempel i form av förvittring genom beröring. På grund av detta har digitala arbetssätt börjat etableras vid exempelvis rekonstruktionsarbete av kilskrift så att arbetet kan utföras utan direkt beröring (Fisseler, Müller & Weichert, 2017). Problemet är att denna typ av arbete upplevs som frustrerande av arkeologerna då det nya digitala arbetssättet skiljer sig från deras tidigare analoga arbetssätt (Woolley et al., 2017). För att lösa denna problematik har en konceptdriven metod använts i uppsatsen. Det har skapats ett digitalt koncept kallat ARCC som kan låta arkeologer arbeta på liknande vis som det analoga naturliga arbetssättet utan att beröra kilskriften. Konceptet ARCC är en kombination av teknologierna: augmented reality, magnetic tracking systems och 3D-printing. Detta koncept är ett exempel på möjligheterna som existerar angående ett praktiskt och etiskt arbetssätt i förhållande till rekonstruktionsarbete av kilskrift. ARCC kan vidareutvecklas för att stärka konceptet, samt också agera indikator på att fler möjligheter inom detta område existerar. / In order to have an understanding of the past archaeologists need to be able to interpret archaeological finds (Why Is Archaeology Important?, 2018). One type of find is cuneiform. Ethical principles has been established to secure the conservation of this kind of find by prohibiting handling that could cause weathering ("Principles of Archaeological Ethics", 2018). Because of this, digital work methods has been established in conjunction with reconstruction of cuneiform in order to eliminate the risk of weathering through touch (Fisseler, Müller & Weichert, 2017). The problem is that this kind of work is found to be frustrating by the archaeologists since this way of work differs from their usual analog work method (Woolley et al., 2017). To solve this problem we have used a concept driven method. The digital concept ARCC has been developed which allows archaeologists to use their usual work method without touching the cuneiform. The concept ARCC is a combination of the technologies: augmented reality, magnetic tracking systems and 3D-printing. This concept is an example of the possibilities that exist regarding a practical and ethical work method regarding reconstruction of cunaiform. ARCC can be further developed to improve the concept, it could also act as an indicator of further possibilities within this area

With the recent rise of 3D-printing as a form of manufacturing and their advantages for quick prototyping there is an interest for 3D-printed optical components. This thesis tests how well 3D-printed quasi-optical components preform and verify measurements with electromagnetic simulations. Measurements were made using a 60GHz FM-CW radar as well with a trihedral reflector, and tested on 3D-printed PLA lenses printed using an Ultimaker 2+. The measurements made are of the refractive index of the material, as well as the focal length of the lenses. Results showed PLA having a refractive index close to n = 1.654 in the 60GHz region. Results also showed the lenses having consistent properties like focal length and gain, two lenses having focal length of 23.7 and 23.9 mm which are close to the simulation of 24.05 mm. These findings shows 3D printed quasi-optical components have sufficient performance for use of prototyping or production depending on use. There are also some questions that have arisen like how does crystallisation in the plastic affect the components properties? And how does the PLA degrading affect the quality of the lenses over time? / På grund av framgångar inom 3D-utskrivning på senaste tiden som en form av tillverkning och dess fördelar med snabb framtagande av prototyper finns det ett intresse för utskrivna optiska komponenter. Detta examensarbete testar hur väl 3D-utskrivna kvasioptiska komponenter funger\-ar och verifierar testresultat med elektromagnetiska simuleringar. Mät\-ning\-arna gjordes med en FM-CW radar och en trihedral reflektor, och testade PLA linser utskrivna med en Ultimaker 2+. Mätningar\-na gjordes på materialets brytningsindex samt linsernas brännvidd. Resultaten visade att PLA har ett brytningsindex nära n = 1.654 i 60GHz området. Resultaten visade även hur linserna har konsekventa egenskaper som brännvidd och förstärkning. De två slutgiltiga linserna hade en brännvidd på 23.7 and 23.9 mm vilket är nära simuleringen på 24.05 mm. Dessa resultat visar att 3D-utskrivna komponenter har tillräcklig prestanda för användning i framtagande av prototyper eller produktion beroende på användning. Det finns en del frågor som kommit till, som hur påverkar plastens kristallisation komponentens egenskaper? Och hur påverkar PLAs nedbrytande linsernas kvalité?

Neuronavigation and transcranial magnetic stimulation (TMS) are valuable tools in clinical and research environment. Neuronavigation provides visual guidance of a given instrument during procedures of neurological interventions, relative to anatomic images. In turn, TMS allows the non-invasive study of cortical brain function and to treat several neurological disorders. Despite the well-accepted importance of both techniques, high-cost of neuronavigation systems and limited spatial accuracy of TMS in targeting brain structures, limit their applications. Therefore, the aim of this thesis was to i) develop an open-source, free neuronavigation software, ii) study a possible combination of neuronavigation and 3D printing for surgical planning, and iii) construct a multi-channel TMS coil with electronic control of electric field (E-field) orientation. In the first part, we developed and characterized a neuronavigation software compatible with multiple spatial tracking devices, the InVesalius Navigator. The created co-registration algorithm enabled tracking position and orientation of instruments with an intuitive graphical interface. Measured accuracy was similar to that of commercial systems. In the second part, we created 3D printed models from patients with neurological disorders and assessed the errors of localizing anatomical landmarks during neuronavigation. Localization errors were below 3 mm, considered acceptable for clinical applications. Finally, in the last part, we combined a set of two thin, overlapping coils to allow electronic control of the E-field orientation and investigated how the motor evoked responses depend on the stimulus orientation. The developed coil enabled the stimulation of the motor cortex with high angular resolution. Motor responses showed the highest amplitude and lowest latency with E-field approximately perpendicular to the central sulcus. In summary, this thesis provides new methods to improve spatial accuracy of techniques to brain interventions. / A neuronavegação e a estimulação magnética transcraniana (EMT ou TMS, do termo em inglês transcranial magnetic stimulation) têm sido apresentadas como ferramentas valiosas em aplicações clínicas e de pesquisa. A neuronavegação possibilita a localização de instrumentos em relação a imagens anatômicas durante procedimentos de intervenção neurológica. Por sua vez, a EMT permite o estudo não invasivo da função cerebral e o tratamento de doenças neurológicas. Apesar da importância de ambas as técnicas, o alto custo dos sistemas de neuronavegação e a reduzida precisão espacial da EMT em ativar estruturas cerebrais limitam suas aplicações. Sendo assim, o objetivo desta tese foi: i) desenvolver um software de neuronavegação gratuito e de código aberto, ii) estudar a combinação entre neuronavegação e impressão 3D para planejamento cirúrgico, e iii) construir uma bobina de EMT multicanal com controle eletrônico da orientação do campo elétrico (CE). Na primeira parte, desenvolvemos e caracterizamos um software de neuronavegação compatível com vários rastreadores espaciais, o InVesalius Navigator. O algoritmo criado possibilitou o rastreamento de instrumentos por uma interface gráfica intuitiva. A precisão medida foi semelhante à de sistemas comerciais. Na segunda parte, imprimimos modelos 3D de pacientes com patologias neurológicas e avaliamos os erros de localização de marcos anatômicos durante a neuronavegação. Os erros de localização foram inferiores a 3 mm, considerados aceitáveis para aplicações clínicas. Por fim, na última parte, combinamos duas bobinas sobrepostas para controlar eletronicamente a orientação do CE, e investigamos como as respostas motoras evocadas dependem da orientação da corrente. A bobina desenvolvida possibilitou estimular o córtex motor com alta resolução angular. As respostas motoras apresentaram maior amplitude e menor latência para orientação do CE aproximadamente perpendicular ao sulco central. Em suma, esta tese fornece novos métodos para melhorar a precisão espacial de técnicas de intervenção com o cérebro.