This dissertation presents the investigation of biologically inspired direction finding (DF) and localization systems, 3D printing solution for RF components and systems, and fundamental aspects of antennas regarding bandwidth and power efficiency. Biologically inspired direction finding and localization systems are explored first. Inspired by the human binaural auditory system, an improved direction of arrival (DoA) estimation technique using two antennas with a lossy scatterer in between them to achieve additional magnitude cues is proposed. By exploiting the incident-angle- dependent magnitude and phase differences between the two antennas with specially designed scatterer, the DoA of an incident signal from two-dimensional (2-D) / three- dimensional (3-D) space can be estimated. Besides, compact DF systems with enhanced directional sensitivity using a scatterer of high permittivity in between adjacent closely spaced electrically-small antennas are examined. Inspired by the human monaural auditory system, a novel single-antenna DF technique is also proposed by exploiting the incident-angle-dependent spectra for a broadband RF signal only. In addition, a wideband superior DF system utilizing Luneburg lens and uniformly placed detectors on the equator of the lens is evaluated. The DoA is estimated using the amplitude distribution of the received signals at the detectors. Moreover, A portable inventory localization system utilizing hybrid RF (for direction, using previously introduced DF techniques) and ultrasound (for distance) signals is proposed and experimentally demonstrated. Next, a multilayer phased array system is designed and individual parts are printed to demonstrate the applicability of hybrid thermal wire-mesh embedding (for conductors) and thermoplastic extrusion (for dielectrics) techniques for additively manufacturing RF17integrated systems. Finally, fundamental aspects of antennas in terms of bandwidth limit for reactive matching and power efficiency for non-Foster matching are analyzed.

This thesis present the fabrication of 2 types of soft wearable electrical devices, utilizing the 3D printing technique. The devices are capable to detect human heart pulse waves and sound waves for health evaluation and speech recognition.

The purpose of this thesis is to investigate how to decrease lead-times of conventionally manufactured prototypes of tools and fixtures. Which could lead to increased knowledge of how an operations site within the automotive industry could utilize additive manufacturing when producing company specific prototypes of tools and fixtures.  The research approach applied in this case study combines a literature review to systematically find relevant literature aligned with the research topic of additive manufacturing or 3D printing related to lead-time reduction and generative design terms. With the help of interviews and observations profound knowledge was gained as preparation before continuing the research. Thereafter, a pre-study was conducted in order to further enhance the understanding of the industrial context of the two chosen fixtures (study objects). Rapid prototyping activities with additive manufacturing processes and technologies of experimentation character was conducted iteratively with both 3D CAD and 3D printing software and hardware. Analysis of the data was conducted through a comparison between lead-times of conventionally manufactured and 3D printed prototypes of the two chosen fixtures. Moreover, identifying potential effects with additive manufacturing of prototypes have with a SWOT analysis.  The case study found that additive manufacturing could significantly decrease lead-times when producing prototypes compared to conventional manufacturing. Furthermore, the results showed that the effects of additive manufacturing are plenty and rather complex due to the fact of this new way to manufacture prototypes. Therefore, the term design for additive manufacturing need first class priority if next steps were to be taken in the additive manufacturing field to enhance industrial and academic benefits.  The research on this subject is strongly constrained by the scarcity of empirical experience and, consequently, by the scarcity of available empirical data. Research publication on the topic are fruitful and plenty but their findings specified to their chosen study objects. This case study gives an up-to-date contribution to the topic of additive manufacturing with endless possibilities to reduce lead-time with rapid prototyping activities that utilizes additive manufacturing. Moreover, the research approach used in this thesis combines 3D CAD data through theoretical concepts and physical objects with additive manufacturing practice. Overall, the results can be used to improve academic research in the topic and promote discussion among different actors entering or within the additive manufacturing field.

Este trabalho avaliou a aplicação das tecnologias de prototipagem rápida por Impressão 3D e FDM (Fused Deposition Modeling) na produção de moldes rápidos. Esta avaliação foi feita com base nas qualidades das peças obtidas por vazamento nos moldes produzidos, bem como nas limitações encontradas em suas utilizações. Foram estabelecidas as principais diferenças do ponto de vista de qualidade, custos, tempos gastos e praticidade. Foram construídos moldes para peças que contemplando vários graus de dificuldades. Para cada ferramental foram obtidos lotes de peças, através dos quais foram analisadas e comparadas as qualidades dos protótipos. / This work evaluated the application of the Rapid Prototyping technologies 3D printer and FDM (Fused Deposition Modeling) in the rapid manufacturing of molds. This evaluation is based on the quality of the parts molded, as well as in the limitations found in the molds applications. As result the main differences related to quality, and usability was established. The molds produced parts with different degrees of geometric difficulties. For each mold, a few prototypes were produced and their qualities compared.

Les techniques de fabrication rapide, issues des techniques de prototypage rapide comme l’impression 3D ou la découpe laser permettent de fabriquer des pièces uniques sans demander d’expertise particulière du procédé mis en œuvre. En revanche la modélisation de nouveaux objets tout comme la personnalisation d’objets existants restent difficiles. En effet, les techniques de prototypages rapides imposent des contraintes sur la géométrie du modèle qui doivent être respectées. Cette thèse présente un ensemble de techniques qui ont pour point commun d’assister l’utilisateur dans la modélisation d’un objet, en tenant compte des contraintes du procédé qui permettra de le fabriquer. À cette fin, l’algorithme prend en charge tout ou partie de la modélisation. En particulier, les problématiques suivantes sont abordées : Tout d’abord, je propose d’améliorer la qualité des objets fabriqués avec une imprimante 3D en minimisant certains défauts qui apparaissent lors de la fabrication. Les approches développées modifient uniquement les algorithmes de pilotage de l’imprimante. En second lieu, je propose d’aider l’utilisateur à prendre en compte les contraintes de fabrication pendant la modélisation. Mes techniques utilisent des informations partielles sur la forme que l’utilisateur souhaite fabriquer, comme le dessin en deux dimensions d’un mécanisme, ou un modèle paramétrique qui définit un meuble. L’algorithme optimise une forme finale qui améliore des critères liés à sa fabrication (gaspillage, encombrement, etc.). Enfin, dans certains cas (e.g. grand public) l’utilisateur n’est pas forcément à même de modéliser ces formes via des logiciels spécialisés. Pour ce cas précis, je propose une technique de synthèse de meubles à partir de spécifications fonctionnelles, e.g. la spécification de poids à porter dans l’espace / The Rapid Manufacturing techniques that emerged from Rapid Prototyping techniques such as 3D printing or laser cutting allow to fabricate unique objects. However, the design of those objects with existing CAD software remain a difficult task: rapid prototyping processes impose constraints on the geometry of the model. This thesis presents a set of techniques that assist the user in the design of an object by taking into account the constraints of the fabrication process. To achieve this, the algorithm automatically performs part of the modelling process. The following problems have been tackled: First, I propose to improve the quality of 3D printed objects by minimizing defects that appear during the fabrication. The technique developed impacts only the algorithm that drives the printer. Then, I propose to help the user to take into account the fabrication constraints during the modelling process. My techniques rely on partial information about the shape that the user wants to fabricate like the 2D sketch of a mechanism or a parametric model of a furniture. The algorithm optimizes the initial shape to improve fabrication objectives(Wastage, etc.) Finally, in some cases, the user does not know how to operate dedicated software. In this case, I propose a synthesis technique of furniture from functionnal specification, e.g. loads that have to be supported in space

A introdução de resinas para uso odontológico se estabeleceu como alternativa à restauração desde meados de 1930, onde a tentativa de utilizar resinas autocuráveis fracassou, porém fortaleceu a pesquisa e esforço em busca de uma alternativa mais viável. Atualmente, a maior parte das resinas odontológicas são fotocuráveis ou termocuráveis e neste trabalho será dado enfoque nas resinas fotopolimerizáveis, que são constituídas, principalmente, por um sistema iniciador (fotoiniciador), monômeros, oligômeros (cadeias maiores formada pela junção de monômeros), aditivos (como cargas, absorvedores de luz, entre outros) e pigmentos. Na última década, um setor que ganhou largas proporções e interesses tecnológicos é o da impressão 3D. Por se tratar de uma técnica aditiva (camada-a-camada) esta forma de impressão revolucionou o modo de se projetar e aplicar diversas estruturas na solução de problemas, inclusive na área odontológica. Dentre os diversos tipos de impressora 3D, a DLP (digital light projection) foi a que apresentou melhor relação de benefícios em função do seu custo reduzido, alta resolução e praticidade na impressão. O presente trabalho apresenta o estudo da influência da cinética de fotopolimerização na qualidade de peças impressas por meio de impressão 3D DLP e como este fator afeta propriedades físicas e químicas, tais como dureza e grau de conversão. Os experimentos de p-DSC juntamente com FT-IR mostraram como a presença de um bloqueador pode afetar a cinética de fotopolimerização e o grau de conversão a curto e longo prazo, onde para o BAPO observa-se uma baixa contribuição deste composto na redução da velocidade, mas para o TPO o resultado é mais acentuado. Com os dados de dureza, foi possível observar que a presença do bloqueador leva a uma diminuição do valor obtido. Já as fotomicrografias obtidas revelaram que o absorvedor UV apresentou grande contribuição para a resolução das peças impressas, com resultado mais significativo para o fotoiniciador TPO. Dados de DSC foram analisados para correlacionar com o monômero residual presente, onde foi observado um pico exotérmico com área praticamente constante em situações otimizadas, levando a uma conclusão que o máximo de resolução está diretamente relacionado com o grau de conversão obtido no processo de impressão 3D. / The introduction of resins for the dental Market was stablished around 1930, where the self-cure resins development failed and lead the world to develop a new alternative for dental application. Recently, most of the dental resin are photo curable or thermal curable and in the present work the first one will be the focus and are composed of an initiation system (photo-initiator), monomers, additives and pigments. In the past decade, another sector, which achieve large proportion and technological interest, is the one about 3D printing. Due to the fact of being an additive technique, this type of 3D printing made a revolution in the way of projecting and building complex structures, even in the dental business. Among all the available 3D printers, the DLP (digital light projection) is the one who showed the best relationship between price, resolution and convenience in 3D printing. This work presents a study of how the photopolimerization kinetics can affect the quality of 3D printed parts and how it affects some physical-chemical properties, like hardness and degree of conversion. The p-DSC experiments within the FT-IR showed that the presence of an UV blocker might affect the photopolimerization kinetics and the degree of conversion in a short and long term, in which for BAPO it shows a lower contribution from this compound in the reaction rate, but for TPO it is more marked. According to the hardness data, it was possible to observe that the presence of an absorber leads to a lower value. In respect to the photomicrographs, it reveals the good contribution of an UV blocker in the resolution obtained for the printed parts, with a better performance when added to the TPO case. For the DSC experiments, the observation is that there is a correlation with residual monomer, where an exothermic spike with constant area was present for the same optimized conditions, leading to the fact that to achieve the best resolution it is necessary to reach a certain degree of conversion during the process of 3D printing.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2018-12-05T11:48:18Z No. of bitstreams: 1 Raissa Gonçalves Caselas.pdf: 4140601 bytes, checksum: 39e478f743f8ad192024eec9ac3c9304 (MD5) / Made available in DSpace on 2018-12-05T11:48:18Z (GMT). No. of bitstreams: 1 Raissa Gonçalves Caselas.pdf: 4140601 bytes, checksum: 39e478f743f8ad192024eec9ac3c9304 (MD5) Previous issue date: 2018-09-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / With the increasing insertion of 3D printing technologies in the industry, it becomes possible to develop new approaches for objects of different uses, allowing the creation of products highly adaptable to users, as well as the possibility of overcoming design barriers. Being aware of the limits of production and mechanical strength of materials as for lower limb prostheses when related to 3D printing, this research focused on the development of upper limb prostheses. Aiming to analyze the aesthetic and functional ways that the production of these prostheses has covered, were proposed case studies that sharpened the user's imagination and allowed them to be brought from the intangible to the palpable. Projects that were once considered to be impractical, with the technological advance are shown to be feasible, since CAD modeling with 3D printing opens new possibilities. Basing on the information sharing and using open source prosthesis designs, it was possible to attest to its reproducibility as well as the recurring aesthetic attributes, thus, two prostheses were printed and constructed with the use of additive manufacturing technology. Based on several authors from different areas, such as Lucia Santaella, Masahiro Mori, Vilem Flusser, João Teixeira, Chris Anderson and Kathryn Allan, as well as product development concepts, it was finally noticed that the aesthetics resulting from this union permeates the cyberpunk universe, introducing people who have physical disabilities not as "imperfect," but through technology, they can be like superhumans. Contrary to what was believed, prostheses showed a certain tendency towards robotization, admitting their inorganic nature and providing other means of personalization / Com a crescente inserção das tecnologias de impressão 3D na indústria, torna-se possível o desenvolvimento de novas abordagens para objetos de usos diversos, permitindo a criação de produtos altamente adaptáveis aos usuários, bem como a possibilidade de vencer barreiras projetuais. Tendo conhecimento dos limites de produção e de resistência mecânica dos materiais quanto as próteses de membro inferior quando relacionados à impressão 3D, esta pesquisa focou no desenvolvimento de próteses de membro superior. Buscando analisar os caminhos estéticos e funcionais que a produção dessas próteses tem cursado, foram propostos estudos de caso que aguçavam o imaginário do usuário e que permitiam trazê-los do intangível ao palpável. Projetos que outrora viam-se como sendo impraticáveis, com o avanço tecnológico se mostram realizáveis, pois a modelagem CAD junto a impressão 3D abrem novas possibilidades. Apoiando-se também no compartilhamento de informações e utilizando projetos de próteses open source, foi possível atestar sua reprodutibilidade, bem como os atributos estéticos recorrentes, assim, foram impressas e construídas duas próteses com a utilização de tecnologia de manufatura aditiva. Nos embasando em diversos autores de áreas distintas como, Lucia Santaella, Masahiro Mori, Vilem Flusser, João Teixeira, Chris Anderson e Kathryn Allan, além de conceitos de desenvolvimento de produtos, percebeu-se, por fim, que a estética que resulta dessa união permeia o universo do cyberpunk, apresentando as pessoas que possuem deficiências físicas não como “imperfeitas”, mas por meio da tecnologia, podem ser como super-humanos. Diferentemente do que se acreditava, as próteses apresentaram certa tendência à robotização, admitindo sua natureza inorgânica e propiciando outros meios de personalização

Additive manufacturing (AM) is currently on the verge of redefining the way we produce and manufacture things. AM encompasses many technologies and subsets, which are all joint by a common denominator; they build three dimensional (3D) objects by adding materials layer-upon-layer. This family of methods can do so, whether the material is plastic, concrete, metallic or living cells which can function as organs. AM manufacturing at the micro scale introduces new capabilities for the AM family that has been proven difficult to achieve with established AM methods at the macro scale. Electrohydrodynamic jet (E-jet or EHD jet) printing is a micro AM technique which has the ability to print at high resolution and speed by exploiting physical phenomena to generate droplets using the means of an electric field. However, when printing metallic materials, this method requires nanoparticles for deposition. To obtain a stable structure the material needs to be sintered, after which the deposited material is left with a porous structure. In contrary, electrochemical methods using the well-known deposition mechanism of electroplating, can deposit dense and pure structures with the downside of slow deposition. In this thesis, a new method is proposed to micro additive manufacturing by merging an already existing technology EHD with simple electrochemistry. By doing so, we demonstrate that it is possible to print metallic structures at the micro- and nanoscale with high speeds, without the need for presynthesized nanoparticles. To achieve this, a printing setup was designed and built. Using a sacrificial wire and the solvent acetonitrile, metallic building blocks such as lines, pillars and other geometric features could be printed in copper, silver, and gold with a minimum feature size of 200 nm. A voltage dependence was found for porosity, where the densest pillars were printed at 135-150 V and the most porous at 260 V. The maximum experimental deposition speed measured up to 4.1 µm · s−1 at 220 V. Faraday’s law of electrolysis could be used to predict the experimental deposition speed at a potential of 190 V with vexp = 1.8 µm · s−1 and vtheory = 0.8 µm · s−1. The microstructure of the pillars could be improved through lowering the applied voltage. In addition, given that Faraday’s law of electrolysis could predict experimental depositions speeds well, it gives further proof to reduction being the mechanism of deposition.

3D printing technology is rapidly advancing and is being increasingly used for biological applications. The spatial control of 3D printing makes it especially attractive for fabricating 3D tissues and for studying the role of geometry in biology. We utilized two different types of 3D printing to engineer vascularized tissues with complex vascular architectures, to use engineered vasculature to treat ischemia, and to study directional endothelial cell migration on curved wave topography. To engineer 3D tissues, perfusable vascular networks must be embedded within the tissue to supply nutrients and oxygen to cells. 3D-printed sugar filaments have previously been used as a cytocompatible sacrificial template to rapidly cast vascular networks. We improved upon the 3D-printed sugar method and used it to fabricate complex vascular geometries that were not previously possible, such as a branched channel geometry, with controlled fluid flow through the channels. We also integrated an approach utilizing vascular self-assembly to generate thick tissues with dense, capillary-scale vessel networks. The vascularized tissues fabricated using 3D-printed sugar successfully integrated with a host vasculature upon implantation and restored perfusion in two different animal models of ischemia. Cell migration critical to numerous biological processes can be guided by surface topography. However, fabrication limitations constrain topography studies to geometries that may not adequately mimic physiological environments. Direct Laser Writing (DLW) provides the necessary 3D flexibility and control to create well-defined curved waveforms similar to those found in physiological settings, such as the lumen of blood vessels. We found that endothelial cells migrated fastest along square waves, intermediate along triangular waves, and slowest along sine waves and that directional cell migration on sine waves decreased at longer sinusoid wavelengths. Interestingly, inhibition of Rac1 decreased directional migration on 3D sine waves but not on 2D micropatterned lines, suggesting that cells may utilize different molecular pathways to sense curved topographies. Our study demonstrates that DLW can be employed to investigate directional migration on a wide array of surfaces with curvatures that are unattainable using conventional manufacturing techniques. / 2020-10-22T00:00:00Z

Dans cette thèse, nous étudions les concepts de durabilité et de responsabilité à l’ère de la numérisation, époque marquée par l’émergence de nouvelles technologies numériques de rupture. Nous cherchons à identifier dans quelle mesure les technologies numériques peuvent contribuer aux objectifs de durabilité et de responsabilité et comment une technologie numérique spécifique peut faciliter l’atteinte de ces objectifs.Ces critères nous ont conduits au choix de la fabrication additive, plus communément connue sous le nom de « technologie d'impression 3D » (3DP). Observée à travers du prisme conceptuel de l'innovation responsable, notre étude dévoile au travers de ses principaux résultats certains des mystères que revêtent les 3DP auprès du grand public. En combinant le concept d'innovation responsable avec une technologie numérique spécifique, nous avons adopté une approche de recherche utilisant la théorie enracinée pour suivre les processus d'adoption/diffusion actuels à partir du terrain, et identifier les utilisateurs précurseurs et influents du domaine des 3DP. Ainsi, les principaux résultats peuvent être divisés en deux thèmes, dans un premier temps pour expliquer les caractéristiques des systèmes sociotechniques dans lequel la 3DP est située et, dans un deuxième temps, discuter des avantages et des défis sociaux, économiques et environnementaux de 3DP pour le grand public. Dans la seconde partie, la première section, consacrée aux caractéristiques du système sociotechnique, se concentre sur le processus d'adoption actuel, l'identification des utilisateurs influents prenant forme dans la culture ‘Maker’ et dans les espaces de coworking. Cette section présente également les caractéristiques actuelles de ces primo utilisateurs et les particularités de 3DP pour le grand public, telles que le déséquilibre hommes-femmes pour les utilisateurs actuels, et la manière dont contribueront la 3DP au développement de nouveaux produits. La seconde section de nos principaux résultats offre une analyse détaillée des avantages et des défis sociaux, économiques et environnementaux spécifiques de 3DP au niveau consommateur.Ces résultats indiquent qu'il existe une attente sociétale croissante auprès des 3DP pour adoucir les systèmes de production actuels et aboutir à des logiques de production plus durables. Par conséquent, les opportunités économiques offrent la possibilité de développer de nouveaux services et produits dans le marché des 3DP, caractérisé par une forte expansion et de faibles barrières à l'entrée, qui séduisent une grande variété de petites et moyennes entreprises (PME). Enfin, la nature environnementale des 3DP au niveau consommateur, même si elle offre des possibilités prometteuses pour préserver les ressources, optimiser la production, maîtriser l’obsolescence planifiée et recycler et réutiliser les matériaux, fait toujours face à un certain nombre de problèmes, qui limitent les apports environnementaux dans le cas d’une adoption de masse. Les contributions théoriques correspondent principalement aux spécificités du processus d'adoption des 3DP au niveau consommateur, à l’identification des caractéristiques des primo utilisateurs et des utilisateurs influents, mais aussi aux implications en termes de développement durable, sujets rarement traités dans la littérature en gestion. Nos principales conclusions apportent également des informations détaillées aux praticiens qui peuvent mener leurs activités entrepreneuriales, en mobilisant ces technologies pour améliorer les modèles d’affaires existants ou en développant des produits et services entièrement nouveaux. Les législateurs peuvent tirer parti des informations sur les pratiques 3DP actuelles et élaborer des politiques pour soutenir la recherche et l'innovation dans le domaine des 3DP ou pour identifier les menaces potentielles pour le public, telles que les risques liés à la propriété intellectuelle ou les problématiques de standard. / This study investigates the concepts of sustainability and responsibility in innovation through the processes of digitalization, marked by the emergence of new disruptive digital technologies. We observe the link between the digitalization and sustainability to understand how a specific digital technology can lead to sustainable and responsible outcomes. These criteria led us to additive manufacturing, or more commonly known, 3D Printing (3DP) technology.We adopted a responsible innovation concept as a set of principles to guide our study on 3DP. Moreover, this study design enabled us to align responsible innovation with existing research methods such as grounded theory. Through a bottom-up research approach, we observed trajectories of the current 3DP adoption/diffusion process and identified early users within their sociotechnical environment where 3DP is currently available. This constituted a solid ground to discuss 3DP sustainable and responsible nature and related implications. Responsible innovation concept, 3DP technology and our research methods are described in the Part I of this document.Part II elaborates main findings that can be divided into two sections. In the first section, we present characteristics of the sociotechnical system, current adoption process, 3DP innovation characteristics, and identify lead users. Current lead users of consumer-level 3DP are seen in the form of Maker culture and the coworking spaces. We present the insights on this specific interaction between the 3DP and Maker culture, whilst also discussing characteristic gender imbalance and new product development.The second section offers detailed analysis of consumer-level 3DP social, economic and environmental implications. Social implications indicate that there is an increasing societal expectation where 3DP is expected to lead a transformation towards more sustainable means of production. Economic implications are concentrated on the business opportunities relying on the growing 3DP market. As an evolving and niche market, current expansion and low-entry barriers are attracting interest of Small and Medium Entrepreneurs (SMEs) who develop new 3DP services and products. Lastly, even though with a promising potential to preserve raw resources, optimize production, tackle planned obsolescence, ensure recycling and reuse of materials, consumer-level 3DP still faces several environmental challenges. Possible rebound effect in energy and resources could lead to consequences that undermine its additive nature, where ecology is not a central topic for 3DP further development.Theoretical contributions of our study can be summarized in the specificities of consumer-level 3DP adoption process, characteristics of the early adopters and sustainability implications. These topics are scarcely covered in management research. Moreover, our key findings also provide detailed managerial contributions for the practitioners and the policy-makers. These can contribute to entrepreneurial activities that demand 3DP alignment with existing business models or development of new products and services based on this technology. Policy-makers can obtain insights on the current 3DP practices that can help guide policies to support research and innovation linked to 3DP technology. Our study insights can assist their understanding of possible threats hidden in Intellectual Property (IP), security and standardization issues related to 3DP technology.Finally, our main intention was to contribute to the ongoing scholar debate about the 3DP technology, digitalization and sustainability. For these purposes, we have developed a detailed thesis monograph offering a broad range of findings, whilst two fully published peer-reviewed publications, alongside several conference papers, ensure public visibility of our work. The published peer-reviewed articles are available in the Appendices section of this document.