O bambu é considerado um dos materiais naturais com a melhor relação resistência por peso. Entre as características responsáveis encontram-se os feixes fibrosos do esclerênquima, que protegem os elementos de condução de água e solutos na planta, além de serem preenchidos pelo parênquima. Os feixes estão distribuídos gradual-mente, da parte interna à externa do bambu, aumentando a rigidez do colmo. Contudo, a morfologia da seção dos feixes fibrosos e a presença da matriz parenquimática no caule ainda não foram totalmente estudados, quanto à sua importância estrutural, nem aplicados em estruturas biônicas. Esse estudo trata do design de estruturas biônicas baseada na caracterização do bambu, por meio de técnicas não-invasivas, de proto-tipagem e de análise por elementos finitos. Um protocolo de amolecimento e secagem para secionamento foi seguido em uma amostra de bambu (Bambusa tuldoides Munro). A superfície da amostra foi analisada por microtomografia computadorizada de raios X de alta resolução. As imagens resultantes permitiram a segmentação dos tecidos constituintes e caracterização em nível celular. Os modelos 3D do parênquima e do esclerênquima foram discretizados para uma análise por elementos finitos não-linear. Os resultados mostraram que o parênquima é configurado como uma matriz celular de baixa densidade e que distribui as tensões em todos os elementos de re-forço na planta, sendo considerado um tecido com importante função estrutural. De mesmo modo, a geometria da seção dos feixes fibrosos apresentou um desempenho mecânico superior às seções referenciais. Ambas características foram aplicadas no desenvolvimento de duas estruturas biônicas, sendo analisadas como mais eficientes em comparação a um modelo da literatura, e impressas em 3D para análise visual. / Bamboo is considered one of the natural materials with the best strength-to-weight ratio. Among the features responsible for its properties are the sclerenchyma’s fiber bundles that protect the conducting elements of water and solutes in the plant, and are filled by parenchyma. Bamboo fibers are gradually distributed from the inner to the outer side of the plant, thus increasing the culm stiffness. However, the morphology of the section of the fiber bundles and the presence of the parenchymatic matrix in the stem have not been fully studied regarding its structural importance, neither applied in bionic structures. This study addresses the design of bionic structures based on the characterization of bamboo, by means of non-invasive techniques, rapid prototyping and finite element analysis. A bamboo sample (Bambusa tuldoides Munro) was col-lected and softening and drying protocols were followed for proper sectioning. The surface of the sample was analyzed by high-resolution X-ray microcomputed tomog-raphy. Resulting images allowed the segmentation of the sample’s constituent tissues and the characterization at a cellular level. The 3D models of the parenchyma and sclerenchyma were discretized for a non-linear finite element analysis. The results showed that the parenchyma is set as a low-density cellular matrix by distributing the stresses among all reinforcement elements in the plant, being considered a tissue with great structural importance. Likewise, the shape of the fiber bundles’ section showed superior mechanical performance compared to reference sections. Both characteris-tics were applied in the development of two bionic structures that were analyzed as more efficient than a literature model, and 3D printed for a visual analysis.

Digital fabrication technologies such as 3D printing is predicted to have a significant impact on our future society. However, the complexity of current 3D modelling softwares  risk deterring novices from engaging with the technology. In this thesis, a series of workshops were conducted to explore the implications for novices to create models out of tangible materials such as clay, paper and LEGO, that were then scanned and printed with a 3D printer. The results show that while the tangible materials create engaging opportunities for novices to engage with digital fabrication technologies such as 3D printing, the materials also provide limitations and constraints depending on their physical properties.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-07-26T14:12:57Z No. of bitstreams: 1 PDF - Janaína Benício Marques.pdf: 14648505 bytes, checksum: d012b9258828a4761e4dc0c746b9ce9a (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2017-08-29T15:31:07Z (GMT) No. of bitstreams: 1 PDF - Janaína Benício Marques.pdf: 14648505 bytes, checksum: d012b9258828a4761e4dc0c746b9ce9a (MD5) / Made available in DSpace on 2017-08-29T15:31:07Z (GMT). No. of bitstreams: 1 PDF - Janaína Benício Marques.pdf: 14648505 bytes, checksum: d012b9258828a4761e4dc0c746b9ce9a (MD5) Previous issue date: 2017-01-25 / OBJECTIVE: To compare earmolds obtained by the CAD / CAM system and the conventional pre-molding method. METHODS: Comfort sensations and anthropometric measures were analyzed in 30 ears of 15 volunteers randomly selected from a private clinic in a Brazilian Northeast Municipality, who underwent two procedures to obtain measurements, a CT scan composing the case group and preforming, constituting the control group. After the preparation of the silicone earmolds, the physical test of the devices was performed by the blind study method, in which the participants were not aware of the origin of each mold. RESULTS: The concepts Regular (53.3%), Good (20%) and Bad (20%), in the control group prevailed, based on the self-perception of the participants, while in the method proposed by the biomodel the concepts Good (73.3%) and Optimum (26.7%). As for the anthropometric linear measurements per ear in each of the evaluation forms: Conventional Preform, Conventional Silicone, Biomodel and Mold proposed significant differences (p <0.05) were found between the evaluation forms in the variables "Intertragic Incision - Top border of the Shell "," Length of the socket "" Depth of External Acoustic Meatus "," Thickness of EAM "and" Volume "in each ear. The coefficient of standard deviation being less than half of the corresponding mean values.CONCLUSION: In view of the above, it is possible to obtain atrial molds from tomographic images with favorable results. / OBJETIVO: Comparar auxiliares de audição obtidos pelo sistema CAD/CAM e pelo método convencional de pré-moldagem. METODOLOGIA: Foram analisadas as sensações de conforto e medidas antropométricas em 30 orelhas de 15 voluntários escolhidos aleatoriamente de uma clínica particular de um município do Nordeste brasileiro, os quais foram submetidos aos dois processos de obtenção de medidas, exame de tomografia computadorizada compondo o grupo caso e pré-moldagem constituindo o grupo controle. Após a confecção dos moldes de silicone, a prova física dos dispositivos foi realizada pelo método do estudo cego, onde os participantes não tinham conhecimento acerca da origem de cada molde. RESULTADOS: Com base na avaliação de autopercepção dos participantes quanto à técnica de obtenção dos moldes prevaleceram, no grupo controle, os conceitos Regular (53,3%), Bom (20%) e Ruim (20%), enquanto no método proposto pelo biomodelo prevaleceram os conceitos Bom (73,3%) e Ótimo (26,7%). Quanto às medidas lineares antropométricas por orelha em cada uma das formas de avaliação: Pré-molde convencional, Silicone convencional, Biomodelo e Molde proposto foram verificadas diferenças significativas (p < 0,05) entre as formas de avaliação nas variáveis ―Incisura Intertrágica – Bordo superior da Concha‖, ―Comprimento do encaixe‖ ―Profundidade de Meato Acústico Externo‖, ―Espessura do MAE‖ e do ―Volume‖ em cada uma das orelhas. Estando o coeficiente de desvio padrão inferior a metade dos valores das médias correspondentes. CONCLUSÃO: Diante do exposto, verifica-se que é possível obter moldes auriculares a partir de imagens tomográficas com resultados favoráveis.

Digital RF phase shifters fabricated using additive manufacturing processes are presented and studied. The purpose is to explain the performance differences between phase shifters fabricated using additive manufacturing and those fabricated with conventional subtractive techniques. All phase shifters are designed to operate at a center frequency of 2.45 GHz with a 100 MHz bandwidth. The 1-bit 45° switched line phase shifters have an average insertion loss of 1.3 dB and a 220 mm2 footprint, while the 1-bit 180° high-pass low-pass phase shifters have an insertion loss 1.56 dB and a 180 mm2 footprint. The 4-bit high-pass low-pass, switched line hybrid phase shifters on the other hand show an average state insertion loss of 5.4 dB and have a 660 mm2 foot print. By carefully analyzing the performance of the various phase shifter designs it is shown that the limiting factors of additive manufacturing technology are the low conductivity of CB028 silver ink in comparison to copper, and the inability to print dielectrics with low surface roughness. Finally, parallel plate capacitors and a spiral inductor designed to be fabricated using additive manufacturing techniques are studied. This is done in order to better understand the advantages and disadvantages of such a design. By analyzing the component’s simulated performance it is shown that 3D printed capacitors and inductors are feasible as long as the capacitance or inductance values needed are low. Large value 3D printed components are impractical for RF applications due to their large size.

This thesis aims to investigate the use of additive manufacturing (AM) as a novel manufacturing process for the production of milli-scale chemical reaction systems. Five well developed additive manufacturing techniques; stereolithography (SL), selective laser melting (SLM), fused deposition modelling (FDM), ultrasonic additive manufacture (UAM) and selective laser sintering (SLS) were used to manufacture a number of miniaturised flow devices which were tested using a range of organic and inorganic reactions. SL was used to manufacture a range of functioning milli-scale flow devices from Accura 60 photoresin, with both simple and complex internal channel networks. These devices were used to perform a range of organic and inorganic reactions, including aldehyde and ketone functional group interconversions. Conversion of products within these reactors, were shown to be comparable to commercially available milli-scale coil reactors. More complex designs, which allowed SL parts to be integrated to existing flow and analytical instrumentation, allowed us to develop an automated reaction analysis and optimisation platform. This platform allowed precise control over the reaction conditions, including flow rate, temperature and reagent composition. We also designed a simplex type reaction optimisation software package that could input data in the form of reaction conversions, peak intensities, and thermocouple data, and generate a new set of optimal reaction conditions. SL parts which incorporated embedded analytical components were also manufactured, which allowed us to perform inline reaction analysis as a feedback method for input into the optimisation platform. Stereolithography was shown to be a highly versatile manufacturing method for designing and producing these flow devices, however the process was shown to be still limited by the range of processable materials currently commercially available. SLM was also used to manufacture a number of functioning milli-scale flow devices from stainless steel and titanium, which had simplistic internal channel designs of diameters ranging from 1 to 3 mm. Again, SLM parts were manufactured which incorporated embedded analytical components, which could be integrated into an automated reaction platform. These devices, unlike parts produced via SL, could be attached to heating platforms to allow us to perform high temperature reactions. This control over the reaction temperature formed an essential part of the reaction optimisation platform. These parts were again used to perform a ketone functional group interconversion. Internal structures of these SLM parts were also visualised via micro computed tomography (μCT or microCT) scanning as well as optical microscopy. FDM was used throughout the project as an inexpensive method of prototyping parts which were to be manufactured via more expensive manufacturing processes. This prototyping allowed the optimisation of intricate design features, such as the manufacture of an inline spectroscopic flow cell for integration with a commercially available LC system. FDM was also proposed as a customisable approach to designing and manufacturing flow devices with embedded components, however the current limitations in build resolution and materials choices severely limited the use of FDM for this application. UAM was also proposed as a novel manufacturing process whereby the build process would allow discrete components to be embedded directly into a flow channel. This was demonstrated by embedding a type-k thermocouple across a 2 mm channel. The data from this thermocouple was monitored during a heated reaction, and used as a method of determining the exact reaction conditions the reaction medium was being exposed to. SLS was also proposed as a possible manufacturing method for milli-scale flow devices, however it proved difficult to remove un-sintered powder from parts with internal channel diameters as high as 5 mm. It was shown that this powder was forming a dense semi solid, due to the large degree of shrinkage upon cooling of the SLS parts, which was compressing the powder. More research into optimum processing conditions is required before SLS could be used for the production of intricate channel networks.

Abstract This report accompanies my Master project in the fields of ceramic and glass, the CRAFT! MA program, Konstfack. In this project I fuse my industrial design toolbox and my current engagement in open-source 3D printing technology with my ceramic and glass craft practice. The first pair brings in notions of innovation and an active approach towards technological change, while the second carry ancient craft methods and knowledge. I develop and make 3D printers for clay and use them as an experimental ceramic work method. In this research based practice I use ceramics as the material for 3D printed glassblowing moulds. This act represents a link between ceramic and glass crafts, one that was known to the ancient Roman craftsmen.  A view on craft and digital innovation Although the computer is in use for several decades now, in most crafts it is still used mainly as an assistive device and we seem not to look at it as a professional tool; as a craft tool. New methods of making are out there. We need to have two toolboxes now: Our traditional one and our new digital one. We can already CAD our concepts, control CNC machines and build 3D-printers customised to our growing new practice. We share our new knowledge on open-source platforms, teach each other through the web (and around the globe) how to apply digital techniques to our craft. We now have the opportunity to join hands with the movements of democratisation of contemporary manufacturing techniques and reinvent our practice, our tools and what new-craft could be.

Nel contesto della nuova rivoluzione industriale, alti livelli di turbolenza, dinamismo, volatilità, globalizzazione, competizione e un diverso ruolo del consumatore riconfigurano il panorama delle supply chain e delle innovazioni. Nonostante il valore co-creato e le ultime innovazioni in ottica customer driven siano ormai elementi imprescindibili, poche ricerche si sono focalizzate sulle caratteristiche di una supply chain guidata dal consumatore e sull’impatto o implementazione della stampa 3D. Pertanto, questa tesi mira ad esplorare gli aspetti principali della customer driven supply chain e della direct digital manufacturing technology. Il Paper I presenta una revisione sistematica della letteratura e fornisce un quadro concettuale utile per organizzare i contributi più recenti sull'argomento, implementando la teoria e suggerendo linee guida per i manager. Il Paper II e Paper III propongono ricerche qualitative mediante singoli casi studio che rispettivamente analizzano come la stampa 3D è in grado di facilitare la supply chain customer centricity attraverso la co-creazione di valore nel settore aerospaziale e come un technology provider può implementare un’innovazione customer centric nel settore della gioielleria italiana. Gli studi suggeriscono modelli concettuali e proposizioni che incrementano la letteratura esistente e guidano i manager. Questa tesi contribuisce all'esplorazione dei recenti progressi in merito all’'orientamento della supply chain e della direct digital manufacturing technology fornendo analisi critiche approfondite relative a diverse metodologie. / In the new industrial revolution, high levels of turbulence, dynamism, volatility, globalization, competition and modified customer’s role reconfigure supply chains and innovations landscape. Even if value co-creation and last technologies towards customer driven orientation are unavoidable elements, few contributions have focused on customer driven supply chain characteristics and on 3D printing impact on supply chain or elements of its implementation. For this reason, the thesis aims to explore the main features of customer driven supply chains and direct digital manufacturing technology. Paper I presents a systematic literature review that shows a conceptual framework able to organize the most recent contributions on the topic, implementing the knowledge on the theme and suggesting guidelines to managers. Paper II and Paper III provide qualitative constructive single case study research respectively focused on how 3D printing can enable supply chain customer centricity by value co-creation in the aerospace sector and how 3D printing can be implemented by a technology provider in the Italian jewellery sector. The studies suggest conceptual framework and propositions for improving existing knowledge and addressing managers. This thesis contributes to the exploration of recent advancements in supply chain orientation and direct digital manufacturing technology by providing deep critical analysis related to diverse methodologies.

With the emerging development of new technology and the constantly falling prices, more companies will find interest in industrial robots. Until today, the typical robot users have been large scale car manufacturers. But there exists a big potential market within the small to medium businesses that already uses of CNC machines. Attracting smaller businesses to start using industrial robots could open up the doors to new possibilities and increase their production. Unfortunately, most people still lack the knowledge of operating and programming industrial robots. But many companies have knowledge in G-code which is normally used in CNC machines. That is why this work is focussing on the development of a software that opens up the possibility to make use of G-code to program advanced robot paths with minimal user input. By striving for easier handling of robots, the vision about a more efficient and automated society will become one step closer. The introduction straightens out the different basic principles of CNC milling machines and robots. This will introduce the reader and highlight the different similarities and differences that exist between robots and CNC mills. The goal of this work has been to create an add-in application for ABB’s off-line programming software RobotStudio that was able to import at least one type of file format commonly used for CNC milling. The program should be able to handle some basic functionality, the focus has been on the standard iso6983 type of G-code. The project started with a literature study that gave the author a better insight in both the previous research within the area but also deeper knowledge of the systems CNC mills and robots. The work continued with the development of a software able to import the specified file format. The software has been built in C# and is built as an add-in software for ABB’s offline programming software RobotStudio. The result presents a software that is able to read different types of G-code and translate them into generated paths in RobotStudio. The software also has an inbuilt function in order to parameterize the G02 and G03 commands that represent curves in G-code into straight line segments of the type MoveL in RobotStudio.

L’objectif de ce travail était de concevoir et réaliser par impression un capteur acoustique capacitif résonant bas coût. Il s’inscrit dans le cadre d’un projet collaboratif de recherche intitulé « Spinnaker », défini par la société Tagsys RFID qui souhaite intégrer ce capteur afin d’améliorer la géolocalisation des étiquettes RFID. Ce travail a débuté par la conception et l’optimisation du design en utilisant la simulation par éléments finis (COMSOL) ainsi que des plans d’expériences (DOE : Design of Experiment). Cette première étape a permis de déterminer les paramètres optimaux et démontrer que les performances obtenues étaient conformes aux spécifications. Nous avons ensuite développé les différentes briques technologiques nécessaires à la réalisation des prototypes en utilisant conjointement l’impression 2D par inkjet et l’impression 3D. Nous avons vérifié la fonctionnalité de ces capteurs à l’aide de mesures électriques capacitives et acoustiques par vibrométrie laser. Nous avons démontré la sélectivité en fréquence des capteurs réalisés et comparé les résultats expérimentaux à ceux obtenus par simulation. Enfin, nous avons enfin exploré la « voie piezoélectrique » qui nous semble être une alternative intéressante au principe capacitif. En l’absence d’encre piézoélectrique commerciale imprimable par jet de matière, nous avons formulé une encre imprimable à base du co-polymère PVDF-TrFE et démontré le caractère piézoélectrique des couches imprimées. Les résultats sont prometteurs mais des améliorations doivent encore être apportées à cette encre et au procédé d’impression avant de pouvoir fabriquer des premiers prototypes. / The objective of this work was to design and fabricate a low cost resonant capacitive acoustic sensor using printing techniques. It falls within the frame of a collaborative research project named “Spinnaker”, set up by TAGSYS RFID, a French company, which has planned to integrate this sensor to improve the geolocalization of their RFID tags. This work started with the design and optimization of the sensor using finite element modeling (COMSOL) and design of experiments (DOE). This first step has enabled the identification of the optimum set of parameters and demonstrated that the output responses were in accordance with the specifications. Then, we have developed the different technological building blocks required for the fabrication of the prototypes using jointly the 2D inkjet printing technique and 3D printing method. The functionality of the sensors has been characterized using both capacitive and acoustic measurements using laser Doppler vibrometer. Experimental results showed that sensitivity and selectivity were within the specifications and in good agreement with the modeling results. Finally, we investigated the piezoelectric approach which could be an interesting option to the capacitive one. Since no inkjet printable piezoelectric ink is commercially available, stable inkjet printable polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) ink has been developed. PVDF-TrFE layers were then successfully printed and characterized. The results were quite promising, however further improvements of the ink and printing process are required before stepping towards piezoelectric based device fabrication.

L'objectif principal est de faire premiers pas vers la conception topologique de structures hétérogènes à comportement non-linéaires. Le deuxième objectif est d’optimiser simultanément la topologie de la structure et du matériau. Il requiert la combinaison des méthodes de conception optimale et des approches de modélisation multi-échelle. En raison des lourdes exigences de calcul, nous avons introduit des techniques de réduction de modèle et de calcul parallèle. Nous avons développé tout d’abord un cadre de conception multi-échelle constitué de l’optimisation topologique et la modélisation multi-échelle. Ce cadre fournit un outil automatique pour des structures dont le modèle de matériau sous-jacent est directement régi par la géométrie de la microstructure réaliste et des lois de comportement microscopiques. Nous avons ensuite étendu le cadre en introduisant des variables supplémentaires à l’échelle microscopique pour effectuer la conception simultanée de la structure et de la microstructure. En ce qui concerne les exigences de calcul et de stockage de données en raison de multiples réalisations de calcul multi-échelle sur les configurations similaires, nous avons introduit: les approches de réduction de modèle. Nous avons développé un substitut d'apprentissage adaptatif pour le cas de l’élasticité non-linéaire. Pour viscoplasticité, nous avons collaboré avec le Professeur Felix Fritzen de l’Université de Stuttgart en utilisant son modèle de réduction avec la programmation parallèle sur GPU. Nous avons également adopté une autre approche basée sur le potentiel de réduction issue de la littérature pour améliorer l’efficacité de la conception simultanée. / High-performance heterogeneous materials have been increasingly used nowadays for their advantageous overall characteristics resulting in superior structural mechanical performance. The pronounced heterogeneities of materials have significant impact on the structural behavior that one needs to account for both material microscopic heterogeneities and constituent behaviors to achieve reliable structural designs. Meanwhile, the fast progress of material science and the latest development of 3D printing techniques make it possible to generate more innovative, lightweight, and structurally efficient designs through controlling the composition and the microstructure of material at the microscopic scale. In this thesis, we have made first attempts towards topology optimization design of multiscale nonlinear structures, including design of highly heterogeneous structures, material microstructural design, and simultaneous design of structure and materials. We have primarily developed a multiscale design framework, constituted of two key ingredients : multiscale modeling for structural performance simulation and topology optimization forstructural design. With regard to the first ingredient, we employ the first-order computational homogenization method FE2 to bridge structural and material scales. With regard to the second ingredient, we apply the method Bi-directional Evolutionary Structural Optimization (BESO) to perform topology optimization. In contrast to the conventional nonlinear design of homogeneous structures, this design framework provides an automatic design tool for nonlinear highly heterogeneous structures of which the underlying material model is governed directly by the realistic microstructural geometry and the microscopic constitutive laws. Note that the FE2 method is extremely expensive in terms of computing time and storage requirement. The dilemma of heavy computational burden is even more pronounced when it comes to topology optimization : not only is it required to solve the time-consuming multiscale problem once, but for many different realizations of the structural topology. Meanwhile we note that the optimization process requires multiple design loops involving similar or even repeated computations at the microscopic scale. For these reasons, we introduce to the design framework a third ingredient : reduced-order modeling (ROM). We develop an adaptive surrogate model using snapshot Proper Orthogonal Decomposition (POD) and Diffuse Approximation to substitute the microscopic solutions. The surrogate model is initially built by the first design iteration and updated adaptively in the subsequent design iterations. This surrogate model has shown promising performance in terms of reducing computing cost and modeling accuracy when applied to the design framework for nonlinear elastic cases. As for more severe material nonlinearity, we employ directly an established method potential based Reduced Basis Model Order Reduction (pRBMOR). The key idea of pRBMOR is to approximate the internal variables of the dissipative material by a precomputed reduced basis computed from snapshot POD. To drastically accelerate the computing procedure, pRBMOR has been implemented by parallelization on modern Graphics Processing Units (GPUs). The implementation of pRBMOR with GPU acceleration enables us to realize the design of multiscale elastoviscoplastic structures using the previously developed design framework inrealistic computing time and with affordable memory requirement. We have so far assumed a fixed material microstructure at the microscopic scale. The remaining part of the thesis is dedicated to simultaneous design of both macroscopic structure and microscopic materials. By the previously established multiscale design framework, we have topology variables and volume constraints defined at both scales.