Дисертації з теми "3D powder printing"
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Touma, Rikard, and Nathalie Pettersson. "3D-printing med träEn möjlighet för framtiden?" Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-92364.
Повний текст джерелаАнотація:
3D-skrivare har många användningsområden och de har blivit vanliga i många industrier.Idag talas det om att denna teknik kan vara en möjlig väg till mer hållbart byggande.Tekniken anses lovande inom byggproduktion bland annat för att det visat sig att den kanreducera materialspillet och ge kortare byggtider. Till viss del används tekniken redan förbyggnadstillverkning, men då främst med betong.Målet med arbetet är att beskriva nuvarande kunskap rörande 3D-printing medträbaserad massa, samt att undersöka möjligheten till att använda en träbaserad massabestående av sågspån, vatten och lignin vid 3D-printing.För att kunna nå målet användes en kombination av litteratursökning och laborativaexperiment. Litteratursökningen användes både för att undersöka tidigare genomförda studiergällande träbaserade material i samband med 3D-printing, samt som inspiration för deingredienser och proportioner som används i de laborativa experimenten.Enbart studier om träbaserad 3D-printing studerades. De testobjekt som togs fram i delaborativa experimenten utvärderades i hållfasthet, dimensionsstabilitet och vidhäftning.Resultaten av det laborativa arbetet tyder på att det framtagna materialet går att extrudera,men att det har låg draghållfasthet. Lagren bands samman bra för samtliga tester, medantryckhållfastheten gav varierande resultat. Högst tryckhållfasthet gavs av den blandning somhade högst andel lignin, samt torkades under längst tid.Slutsatsen är att materialet kan vara till nytta, men att rätt användningsområde börbestämmas, då materialet inte tål alltför stora laster.3D printers have many uses and they have become common in many industries. Today, thistechnology is seen as a possible route to more sustainable construction. The technology isconsidered promising in construction engineering, among other things because it has beenshown that it can reduce material waste and provide shorter production times. To someextent, the technology is already being used for building construction, but then mainly withconcrete.The aim of this study is to describe current knowledge regarding 3D printing with woodbasedpulp and to investigate the possibility of using a wood-based pulp consisting ofsawdust, water and lignin for 3D printing.In order to reach the goal, a combination of literature search and laboratory experiments wasused. The literature search was used both to investigate previously conducted studiesregarding wood-pulp based materials in 3D printing and as inspiration for the ingredients andproportions used in the laboratory experiments.Only studies on wood-based 3D printing were studied. The test objects produced in thelaboratory experiments were evaluated in strength, dimensional stability and adhesion. Theresults of the laboratory work indicate that the produced material can be extruded, but that ithas low tensile strength. The layers bonded well for all tests, while the compressive strengthresults varied. The highest compressive strength was given by the mixture with the highestproportion of lignin and the longest drying time.The conclusion is that the material might be useful, but that the correct area of use should bedetermined, as the material cannot withstand excessive loads.Keywords:
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Nur, Hassan Mohammed. "Fabrication of advanced ceramics and selective metallization of non-conductive substrates by inkjet printing." Thesis, Brunel University, 2002. http://bura.brunel.ac.uk/handle/2438/4823.
Повний текст джерелаАнотація:
Inkjet printing of ceramic components and gold conductive tracks was carried out in this study. A commercial inkjet printer, designed for printing one layer of 2D images on paper, was modified to give adequate resolution, to reverse the substrate for overprinting many layers and to accommodate the increase in thickness of 3D components during printing. Ceramic inks were prepared by wet ball milling and printed to form 3D structures. The powders used were alumina, zirconia, lead zirconate titanate (PZT) and barium titanate. The substrate used for printing the ceramic parts was an overhead transparency. Methods to stop or reduce ink flow were devised and used during printing of the ceramic parts. The alumina and zirconia powders were used for the fabrication of multi-layered laminates. The lead zirconate titanate was used to fabricate components with pillars, walls, vertical channels and x-y-z channel network. During printing of the x-y-z channel network, carbon was used as a support structure and then removed during firing. Barium titanate and carbon powders were used to form the first storey of a capacitor with a multi-storey car park structure. The printed parts were pyrolysed and fired in an oxidising environment and then characterised with scanning electron microscopy. The causes of micro structural defects found were discussed and prevention methods suggested. Organic gold powder was dissolved in methanol and then printed on three different substrates to form conductive gold tracks. The substrates used included alumina, glazed tile and microscope glass slides. The printed tracks were fired in air. The decomposition characteristics of the organic gold compound were studied with TGA and Differential Scanning Calorimetry (DSC). Scanning electron microscope was used to examine the fired gold film for defects and conductivity measurement of the tracks was carried out with a programmable multimeter.
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Goss, Cullen. "SLM 125 Single Track and Density Cube Characterization for 316L Stainless Steel." DigitalCommons@CalPoly, 2019. https://digitalcommons.calpoly.edu/theses/2050.
Повний текст джерелаАнотація:
Selective Laser Melting is a rapidly developing additive manufacturing technique that can be used to create unique metal parts with tailormade properties not possible using traditional manufacturing. To understand the process from a most basic level, this study investigates system capabilities when melting single tracks of material. Individual tracks allow for a wide range of scan speeds and laser powers to be utilized and the melt pools analyzed. I discuss how existing studies and simulations can be used to narrow down the selection of potentially successful parameter combinations as well as the limitations of interpretation for single track information. Once we attain a solid understanding of what parameters perform well at a bead level, we can move onto looking at complete 3D parts. A challenge we have faced is creating near fully dense parts and determining a reliable density measurement technique that is accessible for operators at our university. Our results show that the previously determined optimized scan speed and laser power can consistently create parts with >99.5% density over a range of sizes using an analysis method utilizing readily available equipment and software.
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Fitzgerald, Shawn. "A pneumatic conveying powder delivery system for continuously heterogeneous material deposition in solid freeform fabrication." Thesis, Virginia Tech, 1996. http://hdl.handle.net/10919/46072.
Повний текст джерелаАнотація:
Great improvements are continuously being made in the solid free form fabrication (SFF) industry in terms of processes and materials. Fully functional parts are being created directly with little, if any, finishing. Parts are being directly fabricated with engineering materials such as ceramics and metals. This thesis aims to facilitate a substantial advance in rapid prototyping capabilities, namely that of fabricating parts with continuously heterogeneous material compositions. Because SFF is an additive building process, building parts layer-by-layer or even point-by-point, adjusting material composition throughout the entire part, in all three dimensions, is feasible. The use of fine powders as its build material provides the potential for the Selective Laser Sintering (SLS), ThreeDimensional Printing (3DP), and Freeform Powder Molding (FPM) processes to be altered to create continuously heterogeneous material composition. The current roller distribution system needs to be replaced with a new means of delivering the powder that facilitates selective heterogeneous material compositions. This thesis explores a dense phase pneumatic conveying system that has the potential to deliver the powder in a controlled manner and allow for adjustment of material composition throughout the layer.
Master of Science
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Westbeld, Julius. "Investigation of support structures of a polymer powder bed fusion process by use of Design of Experiment (DoE)." Thesis, KTH, Lättkonstruktioner, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-243867.
Повний текст джерелаАнотація:
In this thesis, support structures of a polymer powder based process called XXXXXXXX™ are examined. These structures are crucial for most additive manufacturing processes. The effects of several factors on five industrially important characteristics of support structures are examined by use of the Design of Experiment (DoE) method. It describes the planning as well as the analysis of the experiments. The experiments are planned in a fractional factorial 211-5 design with 64 specimens, resulting in a resolution of IV. The analysis of the data is done by use of the ANOVA method, with which the significance of effects and interaction effects are checked.I detta examensarbete undersöks stödstrukturer för en polymer-pulverbaserad process kallad XXXXXXXX. Dessa strukturer är väsentliga för de flesta aditiv tillverkning. Med hjälp av metoden "Design of Experiment" (DoE) undersöks effekten av flera faktorer på fem industriellt viktiga egenskaper för stödstrukturer. DoE beskriver både planeringen och analysen av experiment. Experimenten planeras i en fraktionerad faktoriell 211-5 design med 64 provexemplar vilket resulterar i en upplösning av IV. Dataanalysen genomförs med hjälp av ANOVA-metoden, med vilken signifikansen av effekter och interaktionseffekter kan undersökas.
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Clark, Jared A. "The Effects of Build Orientation on Residual Stresses in AlSi10Mg Laser Powder Bed Fusion Parts." Youngstown State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1578819644598848.
Повний текст джерела
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Miller, Jacob T. "Sulfuric Acid Corrosion to Simulate Microbial Influenced Corrosion on Stainless Steel 316L." Youngstown State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ysu151621775594905.
Повний текст джерела
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Fan, Zongyue. "A Lagrangian Meshfree Simulation Framework for Additive Manufacturing of Metals." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1619737226226133.
Повний текст джерела
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GROPPO, RICCARDO. "Sviluppo e Industrializzazione di una macchina LPF e validazione attraverso l'ottimizzazione dei parametri di processo di Ottone CuZn42 e Acciaio Armonico C67." Doctoral thesis, Università degli studi di Modena e Reggio Emilia, 2021. http://hdl.handle.net/11380/1245517.
Повний текст джерелаАнотація:
Le tecnologie di costruzione additiva, dalla loro nascita alle prime applicazioni industriali, hanno fatto un grande salto in termini di sviluppo di hardware e materiali.
La continua ricerca di nuovi mercati e la crescente domanda hanno reso più accessibili i costi di tali tecnologie. Dall'uso dei polimeri per fare prototipi alle polveri metalliche per fare parti meccaniche reali i concetti sono sempre gli stessi, costruendo la parte strato per strato. In termini di denaro dagli anni Ottanta ad oggi il processo di stampa 3D mantiene un trend positivo con molti più aumenti per il futuro.
In termini di flussi monetari ed energetici durante la produzione di parti complesse, le tecnologie di costruzione additiva possono avere incrementi positivi. Con le tecnologie di costruzione additiva viene anche preso in considerazione l’aspetto legato alla misurazione del consumo energetico di produzione per le valutazioni dell'inventario del ciclo di vita. [2]
In molte catene di produzione tradizionali, dove stime affidabili del consumo energetico potrebbero non essere disponibili, l'adozione della tecnologia per costruzione additiva consente ai produttori di fornire ai propri clienti dati affidabili sull'energia incorporata nei prodotti o nei componenti durante la fase di produzione. [2]
È stato dimostrato che la selezione della configurazione dei costi minimi in Additive Manufacturing potrebbe portare all'effetto secondario della riduzione al minimo del consumo energetico di processo. [2]
La mia tesi di dottorato discuterà una specifica tecnologia di produzione additiva, basata sul processo di fusione del letto in polvere utilizzando un LASER come fonte di fusione.
Verranno analizzate le principali componenti costruttive presenti nella macchina prototipo, cercandone le principali criticità (sistema di filtraggio e recupero delle polveri, abbattimento polvere nera, flusso del gas in camera, misura delle perdite di carico nei tratti caratteristici dell’impianto, sistema di raccolta delle polveri, sistema di distribuzione e di deposizione delle polveri sul piatto di stampa) e, nel caso queste causino un arresto anomalo oppure un’irregolarità nella qualità nel componente stampato, se ne svilupperà una modifica oppure una sostituzione radicale del componente in esame.
Verificata la stabilità meccanica dell’intera macchina verranno analizzate le proprietà meccaniche dei campioni ottenuti con acciaio inossidabile X2CrNiMo17-12-2 - AISI316L, polvere di ottone CuZn42 e acciaio C67 - Acciaio Temperato. Le principali proprietà meccaniche richieste per un componente costruito per costruzione additiva sono in termini di resistenza meccanica porosità, densità, durezza Brinell, carico a rottura e tensione di snervamento.
In particolare, verranno effettuati dei rilevamenti della densità del provino mediante misurazione della densità volumetrica relativa con metodo di Archimede. Successivamente verrà stabilita la bontà della rugosità superficiale attraverso acquisizione di mappe per mezzo di un microscopio ottico e attraverso un software per l’analisi d’immagine ne verrà poi misurata la rugosità superficiale media. Lo stesso campione verrà poi utilizzato per misurare la durezza media del materiale per mezzo di un durometro.
Per testare il carico a rottura e il limite di snervamento verranno prodotti dei campioni con geometria ad osso di cane a sezione circolare a cui verrà montato un estensimetro analogico. Il software di elaborazione dei dati elabora la curva sforzo – deformazione.The additive manufacturing technologies, from their birth to the first industrial applications, made a big jump in terms of hardware and material development. The continuing research for new markets along with a growing demand have made sure that the costs of such technologies have become more accessible. From the using of polymers to do prototypes to metal powders to do real mechanical parts the concepts are always the same, building the part layer by layer. In terms of money from the eighties to present days the 3D printing process maintain a positive trend with much more increases for the future. In terms of monetary and energy flows during the production of complex parts, the additive manufacturing technologies can have positive increments. Thus the adoption of Additive Manufacturing also simplifies measurement of the manufacturing energy consumption for life cycle inventory assessments. In many traditional supply chains, where reliable estimates of cumulative energy consumption may be unavailable, the adoption of AM allows producers to provide their customers with reliable data on the energy embedded into products or component during the manufacturing stage. It has been shown that selecting the minimum cost configuration in Additive Manufacturing is likely to lead to the secondary effect of minimizing process energy consumption. My PhD thesis will discuss a specific additive manufacturing technology, based on the powder bed fusion process using a LASER as a melting source. The main construction components present in the prototype machine will be analyzed, looking for the main critical issues (filtering and powder recovery system, black powder abatement system, in-chamber gas flow, measurement of load losses in the characteristic sections of the plant, powder collection system, distribution and powder deposition system on the printing plate) and, if these cause a crash or an irregularity in the quality in the printed component, a radical modification or replacement of this component will develop. Once the mechanical stability of the entire machine has been verified, the mechanical properties of the samples obtained with stainless steel X2CrNiMo17-12-2 - AISI316L, CuZn42 brass powder and C67 steel - Tempered steel will be analyzed. The main mechanical properties required for a component built for additive manufacturing are in terms of mechanical strength porosity, density, hardness, ultimate tensile strength, and yield tension. Measurements of the density of the specimen will be carried out by measuring the relative volumetric density by Archimedes method. Subsequently, the quality of surface roughness will be measured through the acquisition of maps by means of an optical microscope and through an image analysis software the average surface roughness will then be measured. The same sample will then be used to measure the average hardness of the material by means of a durometer. To test the ultimate tensile strength and the yield strength, samples with circular section will be produced to which an analog extensometer will be mounted. Data processing software processes the strain -strain curve.
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Ramírez, Jiménez Guillermo. "Electric sustainability analysis for concrete 3D printing machine." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-258928.
Повний текст джерелаАнотація:
Nowadays, manufacturing technologies become more and more aware of efficiency and sustainability. One of them is the so called 3D printing. While 3D printing is often linked to plastic, the truth is there are many other materials that are being tested which could have several improvements over plastics.One of these options is stone or concrete, which is more suitable the architecture and artistic fields. However, due to its nature, this new technology involves the use of new techniques when compared to the more commonly used 3D printers. This implies that it could interesting to know how much energy efficient these techniques are and how can they be improved in future revisions.This thesis is an attempt to disclose and analyze the different devices that make up one of these printers and with this information, build a model that accurately describes its behavior.For this purpose, the power is measured at many points and later it is analyzed and fitted to a predefined function. After the fitting has been done, an error is calculated to show how accurate the model is when compared to the original data.It was found that many of these devices produce power spikes due to its nonlinear behavior. This behavior is usually related to switching, and can avoided with different devices.Finally, some advice is given focused on future research and revisions, which could be helpful for safety, efficiency and quality.Numera blir tillverkningstekniken alltmer medveten om effektivitet och hållbarhet. En av dem är den så kallade 3Dutskriften. Medan 3Dutskrift ofta är kopplad till plast, är verkligheten att det finns många andra material som testas, vilket kan ha flera förbättringar över plast.Ett av dessa alternativ är sten eller betong, vilket är mer lämpligt inom arkitektur och konstnärliga fält. På grund av sin natur inbegriper denna nya teknik användningen av nya tekniker jämfört med de vanligare 3Dskrivarna. Detta innebär att det kan vara intressant att veta hur mycket mer energieffektiva dessa tekniker är och hur de kan förbättras i framtida revisioner.Denna avhandling är ett försök att studera och analysera de olika enheter som utgör en av dessa skrivare och med denna information, bygga en modell som exakt beskriver dess beteende.För detta ändamål mäts effekten på många punkter och senare analyseras och anpassas den till en fördefinierad funktion. Efter anpassning har gjorts beräknas felet för att visa hur exakt modellen är jämfört med originaldata.Det visade sig att många av dessa enheter producerar spänningsspikar på grund av dess olinjära beteende. Detta beteende är vanligtvis relaterat till omkoppling och kan undvikas med olika enheter.Slutligen ges några råd om framtida forskning och revideringar, vilket kan vara till hjälp för säkerhet, effektivitet och kvalitet.
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Cestari, Francesca. "3D printing of bone scaffolds using powders derived from biogenic sources." Doctoral thesis, Università degli studi di Trento, 2023. https://hdl.handle.net/11572/363403.
Повний текст джерелаАнотація:
This doctoral work was developed in the frame of bone tissue engineering, dealing with the fabrication of scaffolds for the regeneration of bones. At this purpose, calcium phosphates derived from natural sources are very interesting because they are more similar to the bone mineral and possess better bioactivity. Indeed, the bone mineral is different from synthetic hydroxyapatite as it is non-stoichiometric, nanosized, it presents a high degree of disorder and contains many additional ions and impurities such as CO32-, Mg2+, Sr2+, Na+, etc. These characteristics can be easily obtained by synthesizing hydroxyapatite from natural sources, such as corals, starfishes, seashells, animal bones, bird eggshells etc. The natural sources used in the present work are three types of biogenic calcium carbonate, i.e. calcium carbonate that is produced by living organisms in the form of aragonite or calcite. Among the different sources, three biogenic calcium carbonates were chosen: cuttlefish (Sepia Officinalis) bones, mussel (Mytilus Galloprovincialis) shells and chicken eggshells. Besides their abundance and availability, they were selected because of their different composition: aragonite in cuttlebones, calcite in eggshells and a mixture of aragonite and calcite in mussel shells. After the first chapter, which is a theoretical introduction, this thesis is divided into other five chapters. Chapter 2 contains a careful characterization of the three biogenic raw materials while Chapter 3 deals with the synthesis of hydroxyapatite starting from these natural sources. The process developed here takes place entirely at nearly room temperature, which allows the organic part of the biological materials to be preserved. This synthesis process is basically a wet mechanosynthesis followed by a mild heat treatment (up to 150°C). The study focuses on the influence of several process parameters on the synthesis efficiency: temperature, milling time, pH and raw material. The temperature used to dry the slurry after the wet ball-milling was found to be the most important parameter, the higher the temperature the faster the conversion of CaCO3 into hydroxyapatite. Moreover, aragonite was found to transform more easily into hydroxyapatite with respect to calcite, and also to follow a different reaction path. The synthesis process described in Chapter 3 allowed to produce different bio-derived powders that were found to be non-stoichiometric, nanosized, carbonated hydroxyapatites, containing also additional ions, especially Mg2+ in the eggshell-derived material and Sr2+ in the cuttlebone-derived one. These powders were then used as a starting point for the studies presented in the next three chapters.
Chapter 4 shows a very preliminary evaluation of the interaction with human cells in vitro. First, the as-synthesized powders were consolidated by uniaxial pressing and sintering at temperatures between 900°C and 1100°C and their crystallographic composition was analyzed. Then, after having established the non-cytotoxicity of the sintered pellets, osteoblasts from human osteosarcoma cell line were seeded on the pellets and their behavior after 1, 3 and 5 days of culture was observed by confocal microscopy. In general, all materials promoted good cell adhesion and proliferation, especially the eggshell-derived one. At this point, the bio-derived materials were found to induce a good cellular response but, in order to foster the regeneration of bones, a scaffold must also contain a large amount of interconnected porosity. Among the numerous methods to fabricate porous structures, additive manufacturing is surely very attractive due many advantages, such as the possibility of customizing the shape based on tomography images from the patients, the fact that no mold is needed and the freedom of fully designing the porosity. Indeed, not only the size and the amount of porosity are important, but also the shape of the pores and their position and orientation have a deep effect on the interaction with the cells. Therefore, Chapter 5 and Chapter 6 deal with the fabrication of scaffolds by 3D printing, following two different approaches. In the study presented in Chapter 5, the powders synthesized from cuttlebones, mussel shells and eggshells were used in combination with a thermoplastic polymer (PCL, polycaprolactone) to obtain bioactive composites. Composite materials made of 85 wt% PCL and 15 wt% bio-derived hydroxyapatite were used to fabricate porous scaffolds by extrusion 3D printing. The biological in vitro tests showed that the composite scaffolds possess better bioactivity than the pure PCL ones, especially those containing mussel shell- and cuttlebone-derived powders, which promoted the best cell adhesion, proliferation and metabolic activity of human osteosarcoma cells after 7 days of culture. In addition, the elastic compressive modulus, which was found to be between 177-316 MPa, thus in the range of that of trabecular bone, was found to increase of about ∼50% with the addition of the bio-derived nanopowders. Finally, in Chapter 6, the cuttlebone-derived powder was used to fabricate porous bioceramic scaffolds by binder jetting 3D printing. Due to serious technical issues related to the printing of a nanosized powder, 10 wt% of bio-derived powder was mixed with a glass-ceramic powder with bigger particle size. Moreover, the organic part of the cuttlebone had to be previously eliminated by a heat treatment at 800°C. Thanks to the great freedom of design that is allowed by the binder jetting process, scaffolds with two different pore geometries were fabricated: with pores of uniform size and with a size-gradient. Indeed, natural bone possesses a gradient in porosity from the core to the surface, from porous trabecular bone to dense cortical bone. The sintered scaffolds showed a total porosity of ∼60% for the pure glass-ceramic and ∼70% for the glass-ceramic with 10 wt% of cuttlebone-derived nanoparticles, which most probably slowed down the densification by limiting the contact between the glassy particles. All the bioceramic scaffolds promoted good adhesion and proliferation of human bone marrow-derived mesenchymal stem cells in vitro, without any significant difference between the different samples. However, the scaffolds with the cuttlebone-derived powder and with gradient porosity showed the greatest decrease of metabolic activity after 10 days of culture, which could be accounted as a sign of differentiation of stem cells.
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Ma, Da. "Improving the Strength of Binder Jetted Pharmaceutical Tablets Through Tailored Polymeric Binders and Powders." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/101030.
Повний текст джерелаАнотація:
Additive Manufacturing (AM) provides a unique opportunity for fabrication of personalized medicine, where each oral dosage could be tailored to satisfy specific needs of each individual patient. Binder jetting, an easily scalable AM technique that is capable of processing the powdered raw material used by tablet manufacturers, is an attractive means for producing individualized pharmaceutical tablets. However, due to the low density of the printed specimens and incompatible binder-powder combination, tablets fabricated by this AM technology suffer from poor strength. The research is introducing an additional composition in the binder jetting powder bed (e.g., powdered sugar) could significantly enhance the compressive strength of the as-fabricated tablets, as compared with those tablets fabricated without the additional powder binding agent. However, no previous research demonstrated comprehensive approaches to enhance the poor performance of the 3D printed tablets. Therefore, the goal of this work is to identify processing techniques for improving the strength of binder jetted tablets, including the use of (i) novel jettable polymeric binders (e.g., 4-arm star polyvinylpyrrolidone (PVP), DI water, and different i) weight percentage of sorbitol binder) and (ii) introducing an additional powder binding agent into the powder bed (e.g.., different wt% of powdered sugar).M.S.
Three-dimensional printing is well-known as 3D printing. 3D printing pills are printed from the 3D printer. As of today, we now stand on the brink of a fourth industrial revolution. By the remarkable technological advancements of the twenty-first century, manufacturing is now becoming digitized. Instead of using a large batch process as traditional, customized printlets with a tailored dose, shape, size, and release characteristics could be produced on- demand. The goal of developing pharmaceutical printing is to reduce the cost of labor, shorten the time of manufacturing, and tailor the pills for patients. And have the potential to cause a paradigm shift in medicine design, manufacture, and use. This paper aims to discuss the current and future potential applications of 3D printing in healthcare and, ultimately, the power of 3D printing in pharmaceuticals.
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Zhao, Kunchen. "3D Printed Frequency Scanning Slotted Waveguide Array with Wide Band Power Divider." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555589955819802.
Повний текст джерела
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Thienen, Stefan, and Thomas Gellner. "Flexible and easy to engineer servo-hydraulic actuators using 3D printing manufacturing process." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71208.
Повний текст джерелаАнотація:
Already since some time, Bosch Rexroth offers solutions as compact servo hydraulic actuators (SHA). Because there are lot of requests from the market, we thought about reducing the inquiry processing time and delivery time by designing a kit system for the SHA solutions. This system should be flexible enough to cover different technical solutions (e.g. cylinder), functionalities and design styles [... aus dem Text]
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Stephenson, Joshua A. "A Study of RF/Microwave Components Using Fused Deposition Modeling and Micro-Dispensing." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6955.
Повний текст джерелаАнотація:
The design and study of multiple RF direct digital manufactured (DDM) devices are presented in this work. A 2.45 GHz, 180°; hybrid coupler is designed to provide the space required for other system components. The coupler is designed and manufactured on a 32 mil Rogers 4003C substrate and adapted to a 100% in-fill acrylonitrile butadiene styrene (ABS) substrate. A size reduction of 66% is accomplished with a bandwidth of 16%. A DDM Ku band connector is modeled and fabricated using varying relative dielectric constants of 50% and 100% in-fill ABS. The connector maintains less than 0.45 dB of insertion loss up to 14 GHz and greater than 10dB of return loss up to 15 GHz. A lumped component model is also developed to model the damaged transition of the connector with agreement to numerical electromagnetic simulation software. Lastly, a thermal and RF study of a Ku band power amplifier (PA) is performed. Two 5 mil 100% in-fill ABS PA test fixtures are fabricated with a varying number of vias. The designs are biased at various operating points to collect thermal and RF data. The PA operates at 151°C before melting the ABS substrate. A thermal model is developed from the measurement data to predict the temperatures at given power levels with good agreement between simulation and model data.
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Sharan, Kumar Varun. "Study of Binding Copper Powders by Electrochemical Deposition." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1471346137.
Повний текст джерела
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Wienhausen, Arne Hendrik [Verfasser], Doncker Rik W. [Akademischer Betreuer] De, and Andrei [Akademischer Betreuer] Vescan. "High integration of power electronic converters enabled by 3D printing / Arne Hendrik Wienhausen ; Rik W. de Doncker, Andrei Vescan." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1220082368/34.
Повний текст джерела
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Feng, Ziang. "Wearable Power Sources and Self-powered Sensors Based on the Triboelectric Nanogenerators." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/103020.
Повний текст джерелаАнотація:
The triboelectric nanogenerator (TENG) has attracted global attention in the fields of power sources and self-powered sensors. By coupling the omnipresent triboelectrification effect and the electrical induction effect, the TENGs can transduce ambient mechanical energy into electrical energy. Such energy could be consumed instantaneously or stored for later use. In this way, they could be deployed distributedly to be compatible power sources in the era of the internet of things (IoTs), completing the powering structure that is currently relying on power plants. Also, the electrical signals can reflect the environment changes around the TENGs. Thus, the TENGs can serve as self-powered sensors in the IoTs. In this work, we adopted two approaches for TENG fabrication: the thermal drawing method (TDP) and 3D printing. With TDP, we have fabricated scalable fiber-based triboelectric nanogenerators (FTENG), which have been woven into textiles by an industrial loom for wearable use. This fabrication process can supply FTENG on a large scale and fast speed, bridging the gap between the TENG and weaving industry. With 3D printing, we have fabricated TENGs that are compatible with the shape of arbitrary substrates. They have been used as biocompatible sensors: human-skin-compatible TENG has been used to recognize silent speech in real-time by sensing the chin movement; the porcine-kidney-shaped fiber mesh has been used to monitor the perfusion rate of the organ. These works have extended the territory of TENGs and can be critical components in the IoTs.Ph.D.
Portable electronic devices have become important components in our daily lives, and we are entering the era of the Internet of Things (IoTs), where everyday objects can be interconnected by the internet. While electricity is essential to all of these devices, the traditional power sources are commonly heavy and bulky and need to be recharged or directly connected to the immobile power plants. Researchers have been working to address this mismatch between the device and power systems. The triboelectric nanogenerators (TENG) are good candidates because they can harvest energy in the ambient environment. The users can use them to generate electricity by merely making the rubbing motion. In this work, we report two fabrication methods of the fiber-based triboelectric nanogenerators (FTENG). With the thermal drawing process, we have fabricated sub-kilometer-long FTENG and wove it with the regular cotton yarn into textiles. The wearable power source is human friendly as it does not induce any extra weight load for the user. Besides, we have demonstrated that such long fibers can work as self-powered distributed sensors, such as a Morse code generator. With 3D printing, we have fabricated FTENG-based devices that conform to the working substrates, which can be any shape. We have employed them as biofriendly sensors to translate the chin movement during speaking to language and to monitor the perfusion rate of a pig kidney. The FTENGs have offered excellent comfortability to the users and can play a vital role in reframing the power structure to be compatible with IoTs.
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Stratton, John W. i. "A Study of Direct Digital Manufactured RF/Microwave Packaging." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/6031.
Повний текст джерелаАнотація:
Various facets of direct digital manufactured (DDM) microwave packages are studied. The rippled surface inherent in fused deposition modeling (FDM) fabricated geometries is modeled in Ansoft HFSS, and its effect on the performance of microstrip transmission lines is assessed via simulation and measurement. The thermal response of DDM microstrip transmission lines is analyzed over a range of RF input powers, and linearity is confirmed over that range.
Two IC packages are embedded into DDM printed circuit boards, and their performance is analyzed. The first is a low power RF switch, and the second is an RF front end device that includes a low noise amplifier (LNA) and a power amplifier (PA). The RF switch is shown to perform well, as compared to a layout designed for a Rogers 4003C microwave laminate substrate. The LNA performs within datasheet specifications. The power amplifier generates substantial heat, so a thermal management attempt is described.
Finally, a capacitively loaded 6dB Wilkinson power divider is designed and fabricated using DDM techniques and materials. Its performance is analyzed and compared to simulation. The device is shown to compare favorably to a similar device fabricated on a Rogers 4003C microwave laminate using traditional printed circuit board techniques.
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Beckmann, Bastian. "Additive manufacturing of hydraulic manifolds - a holistic approach across the entire value chain." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71083.
Повний текст джерелаАнотація:
Manifolds usually consist of metallic, rectangular base bodies into which lines are inserted by means of drilling, thus logically linking the built-on or built-in valves according to the hydraulic circuit diagram. Using additive manufacturing methods, additional degrees of freedom can be used in the design of manifolds, resulting in further benefit in hydraulic drives and their controls. The challenge is not only to understand and apply additive manufacturing technology, but also to align the entire value chain with it.
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Thompson, John Ryan. "RELATING MICROSTRUCTURE TO PROCESS VARIABLES IN BEAM-BASED ADDITIVE MANUFACTURING OF INCONEL 718." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1401699643.
Повний текст джерела
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Kuntz, Sarah Louise. "Feasibility of Attaining Fully Equiaxed Microstructure through Process Variable Control for Additive Manufacturing of Ti-6Al-4V." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1464557846.
Повний текст джерела
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Lin, Jiou-Wei, and 林久瑋. "3D metal powder printing sintering parameter studies." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/vbf7f7.
Повний текст джерелаАнотація:
碩士國立虎尾科技大學
機械與電腦輔助工程系碩士班
105
In the current industry, integrated manufacturing is highly competitive. As 3D printing continue to develop, the techniques and output value are also expending. In the present domestic market, 3D printing with PLA or ABS filament wires are the most common materials. Due to the low-cost and easy operation, the machine is often purchased by schools as a teaching tool. As for the metal 3D printing, it needs to insert protective gas in a closed off space, through laser sintering and stack-build to create an object with metal powder, although such techniques can produce complex parts, very few technical developments are found in the domestic market due to the high cost. The purpose of this study is to focus on the research of 3D metal powder sintering techniques and process. Through laser sintering experiments with different metal powder mixtures to confirm possible powder sintering, then use different laser power, scanning speeds, frequencies and path spacing parameters to conduct powder sintering experiments under different experimental conditions. By using optical microscope and Vickers Hardness tester to verify sintering products and using Taguchi method to find out best parameter combinations. The conclusions of the study are summarized as follow 1.In this study, the powder mixing mechanism was designed and used, the ratio of copper and tin powder for the mixing mechanism was 18: 1 2.If the scanning rate is higher than 30mm/s, the powder indicates insufficient temperature and shows a splash phenomenon which is not conducive to sintering. This will subsequently impact on the porosity and hardness analysis experiments. 3.Through Taguchi analysis, the best combine parameters for pore-space were found. The best pore-space is 4.712%, the laser power is 80%, and the scanning speed is 7mm/s, the frequency is 30k, and the path-space is 0.05mm. 4.Through Taguchi analysis, the best combine parameters for Vickers Hardness were found. The best pore-space is 134.423HV, the laser power is 100%, the scanning speed is 7mm/s, the frequency is 33K, and the path-space is 0.07mm.
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Jhao, Hong-Jin, and 趙宏晉. "3D Printing Plate with Residual Powder Removing System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/06107652028235160423.
Повний текст джерелаАнотація:
碩士國立雲林科技大學
機械工程系
103
Traditionally, the residual powder removing process after selective laser sintering can’t be the finished in the selective laser sintering platform. However, the residual powder removing process always causes the material powder dusty. The dust has an adverse effect on the mechanical systems. In addition, it will also cause indoor pollution. The operator must wear the mask to avoid dust into the lungs. In this thesis, the development of building platform with residual powder removing system is presented. The objective is to improve the material powder dusty problem and avoid the indoor pollution during the residual powder removing process. The design concept is to build in a residual powder removing system in the selective laser sintering platform. The residual powder can be removed in the selective laser sintering platform after the sintering process. It will avoid indoor pollution problem and reduce health hazards to the operators. In addition, the increasing sintering area design is also presented in this thesis. This study starts with the patent analysis to avoid the patent infringement. SolidWorks and AYSYS Workbench are used to design and evaluate the structure parts. A prototype of the building platform with residual powder removing system is fabricated. Some experiments are also carried out in this study to confirm the feasibility of the system.
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LIU, WEI HUNG, and 劉威宏. "Polymer materials for plaster powder type 3D Printing." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/fsbh47.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
分子科學與工程系有機高分子博士班
105
3D printing is a fast manufacturing process in recent years and is therefore a popular research project. Binder jetting is a very growth technology, the molding material in the slot, according to the cut out of the output of the image file, and then use the printer. The nozzle sprayed glue, need to cure part of the adhesion together, and then covered with a layer of new powder layer, once again ejected the glue will be powder adhesion, cycle until the full shape so far, most of the absorbent material can be used as powder 3D print Materials, and according to different materials can be applied to the manufacturing process will be different, Binder Jetting 3D printing industry can be said that is worth further development of one of the technologies. Although the technology of Binder Jetting is now known to reach 0.1mm, but according to the use of gypsum material of the machine physical test and relevant test found that the real can achieve the precision is between 0.15 to 0.2mm , And the material will have the collapse of the shortcomings of the formation, this article is to explore the gypsum is added after the modification of polymer materials, whether the accuracy can be improved, as well as the strength and ductility of the shape of the discussion.
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Hu, Shu-Rui, and 胡書睿. "The Development of 3D Metal Powder Printing Mechanism." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/m47dk8.
Повний текст джерелаАнотація:
碩士國立虎尾科技大學
機械與電腦輔助工程系碩士班
104
Since 2008, 3D printing technologies have been enhanced considerably following the expiration of 3D printing patents. Previously, 3D printers were limited to providing product proofs for designers; current technologies overcome challenges typically associated with manufacturing difficulties, the inability to process directly, and lengthy lead times because 3D printers can directly print components for end products. This study modified the structure of existing 3D printers to construct a 3D metallic powder-sintering device through integrating printing processing technology with metallic powders The structure included a powder feeder, compacting mechanism, and substrate-plate lifting mechanism. Copper was used as the powder material for selective laser sintering. The substrate plate was covered with an evenly distributed layer of metallic powder, which was levelled using a flattener The sintering device fused the selected objects by selectively sintering the metallic powder with a laser beam, and the feeding mechanism distributed a new layer of powder after the substrate plate was lowered. The steps of feeding, levelling, and laser sintering were repeated until the final product was produced. A dial indicator was employed to measure the repeatability of the x- and z-axes. Through the powder-feeding experiment, we determined that the thickness of each layer of the sintered body can be adjusted between 0.1 and 0.4 mm to ensure the feasibility of a simple 3D metallic powder-sintering mechanism. Furthermore, in the powder-sintering experiments, parameters such as the laser power, velocity, frequency, and path interval were adjusted An electron microscope and Vickers hardness tester were employed to inspect the sintered products after the sintering experiment. The Taguchi method was used to obtain the optimal combination of parameters.
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Mandal, Sourav. "Fabrication, micro-computed tomography based quantitative 3D microstructure evaluation of 3D printed bioceramic scaffolds and FE modelling of biomedical implant prototypes." Thesis, 2018. https://etd.iisc.ac.in/handle/2005/5337.
Повний текст джерелаАнотація:
In summary, this thesis provides the following outcomes:
a) Formulation of novel powder-binder combination for 3D powder printing of
resorbable bone-tissue scaffold. b) The effect of post-processing approach on
the macro and microstructure, phase composition and mechanical properties
of a 3DPP system (POP-based). c) Extensive use of ¹CT to provide 3D qualitative
and quantitative microstructural analyses along with in situ mechanical
characterisation of failure behaviour. d) Establishment of a non-destructive
workflow on the basis of ¹CT imaging coupled with FE modelling or analysis
(FEM or FEA) for local mechanical property prediction. Taken together, this dissertation
established 3D powder printing as a viable manufacturing technique
to fabricate designed porous scaffolds and also the efficacy of ¹CT-FEA modelling
based combinatorial approach for local mechanical response in porous
scaffolds and dense biomedical device prototypes
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YANG, CHI-WEN, and 楊琦雯. "A Molecular Dynamic Study on Laser Powder Bed Fusion Additive Manufacturing (3D Printing) Process Using Nanoscale Copper Powder." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3u9zk3.
Повний текст джерелаАнотація:
碩士嘉南藥理大學
應用空間資訊系
106
In this present study, the molecular dynamics investigations on solid and hollow spherical copper nanoscale powders during the laser powder bed fusion additive manufacturing (3D printing) process are exhibited under different powder sizes and heating rates. The sizes of copper powders are varied from 12a, 18a and 24a, respectively. The six combinations of both solid and hollow spherical two-powder-model are chosen, respectively. The common neighbor analysis, neck width, mean square displacement, and gyration radius are utilized to investigate the nanoscale physical properties, which are coalescence and melting temperature, of copper powders under laser sintering process. Whatever solid or hollow spherical copper powders, we found that the solid-state sintering automatically takes place at room temperature. Moreover, except that the powder size and the heating rate of metal powder significantly affect the physical properties, the result of this study also shows that the geometry of the nanoscale powders is also an important role in the 3D printing process.
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CHIANG, YU-WEN, and 江育文. "Molecular Dynamics Investigations on Characteristics in Laser Powder Bed Fusion Additive Manufacturing(3D Printing) of Titanium and Tantalum Nanoparticles under Different Heating Rates." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/97553202531272395339.
Повний текст джерелаАнотація:
碩士南臺科技大學
機械工程系
104
In the present study, the molecular dynamics investigations on physical characteristics of solid and hollow spherical titanium and tantalum nanoparticles during laser powder bed fusion additive manufacturing (3D Printing) process are exhibited under different sizes and heating rates. As for titanium, the sizes of titanium nanoparticles are varied from 16a, 20a and 24a, respectively. In addition, the sizes of tantalum nanoparticles are varied from 10a, 16a and 24a, respectively. Regarding both titanium and tantalum, the six combinations of both spherical solid and hollow two-nanoparticle-model are chosen, respectively. The bond angle, neck width, potential energy and gyration radius are utilized to realize the physical properties of nanoscale metallic powders under laser sintering process. Whatever solid or hollow titanium and tantalum nanoparticles, the present results show that the solid state sintering automatically takes place at room temperature. The temperatures of phase change, coalescence, melting of titanium nanoparticle decreased with particle diameter decreasing, but increased with heating rate increasing. Moreover, the temperatures of phase change, coalescence, melting of hollow spherical titanium nanoparticle are also lower than those of solid ones. Meanwhile, we also found that the temperatures of coalescence and melting of tantalum nanoparticle decreased with particle diameter decreasing, but increased with heating rate increasing. At the same time, the temperatures of coalescence and melting of nanoscale hollow tantalum nanoparticle are lower than those of solid ones, also. It is found that the phase change temperature (1220K-1325K) of nanoscale titanium is a little higher than that of bulk titanium, 1155K. Nevertheless, the melting temperature (1200K-1350) of nanoscale titanium is much lower than the melting point of bulk titanium, 1940K. At the same time, it is also found that the melting temperature (2400K-3000K) of nanoscale tantalum is much lower than the melting point of bulk tantalum, 3290K.
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LI, CHAO-CHEN, and 李兆宸. "Molecular Dynamics Investigations on Characteristics of Nanoscale Pure Niobium, Pure Zirconium and Binary Alloy Niobium-Zirconium Metal Powders Applied to Powder Bed Fusion 3D Printing During Laser Heating Process." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/dcptd7.
Повний текст джерелаАнотація:
碩士南臺科技大學
機械工程系
106
In this present study, the physical characteristics of nanoscale niobium zirconium alloy powder applied on the powder bed fusion laser sintering is computed during 3D printing process by molecular dynamics simulation method with embedded atom method potential. Simulation of solid nanoscale base metals with six sets of double-ball models (5.28nm-5.28nm, 5.28nm-6.6nm, 6.6nm-6.6nm, 5.28nm-7.92nm, 6.6nm-7.92nm, 7.92nm-7.92nm) Powder, hollow nanoscale pure niobium metal powder; with six sets of double-sphere models (5.17nm and 5.17nm, 5.17nm and 6.46mn, 5.17nm and 7.75nm, 6.46nm and 6.46nm, 6.46nm and 7.75nm, 7.75nm 7.75nm) simulated solid nanoscale pure zirconium metal powder; with six sets of double-sphere models (5.57nm-5.57nm, 5.57nm-6.96nm, 6.96nm-6.96nm, 5.57nm-8.35nm, 6.96nm-8.35nm, 8.35) Nm-8.35nm) simulation of solid nanoscale binary alloy niobium-zirconium metal powders,that are created and laser-sintered under different heating rates (1K/ps, 0.5K/ps, and 0.25K/ps, respectively), and then the neck width, radius of gyration, structural change, potential energy, and root mean square displacement of nanoscale powder are analyzed and discussed. It is found that nanoscale powder has the phenomena of spontaneous solid-state sintering at room temperature. Average coalescence temperature and melting temperature decrease with heating rate dreasing when powder size fixed, and they decrease with powder size decreasing when heating rate fixed also. Therefore, it is suggested that the power of laser beams could be lower during 3D printing process in order to heat nanoscale niobium zirconium alloy powder.
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Yu-YangHuang and 黃昱陽. "Analysis of Heat Affected Zone in Steel Powder and Simulation of Heat Transfer in the Worked Zone by Selective Laser Melting for 3D Printing Applications." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/65580925323921314975.
Повний текст джерелаАнотація:
碩士國立成功大學
機械工程學系
104
This study focuses on selective laser melting (SLM) process, the melting zone of the powder and heat affected zone of the substrate influence the quality of 3D printing objects. In the present study, the controlling factors of SLM process are the laser power, laser scanning velocity, and thickness of powder bed. Because the technology of SLM is developing, the finite element model of SLM process is necessary to forecast the results. In order to check the accuracy of the simulational model, the experiment with same conditions is used to contrast two results. In this case, the material of powder is SKD61, and the substrate is S45C. After SLM printing, the depth, width, and length of melting zone, and heat affected zone of the substrate are measured to realize the influence of laser controlling parameters. Meanwhile, discussing the tendency for different combinations of laser parameters.
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Barui, Srimanta. "Understanding quantitative process physics of 3D binderjet printing with validation in Ti-6Al-4V and inkjet bioprinting of mammalian cells." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4615.
Повний текст джерелаАнотація:
In the field of additive manufacturing, laser or electron beam based 3D printing is widely investigated for biomedical applications. However, much less explored is the binderjet 3D printing, which allows processing of biomaterials at physiologically relevant conditions. In this context, this thesis presents a set of experimental and theoretical analysis to develop a quantitative understanding of the transient process physics of the binderjet 3D printing. In the first part, maltodextrin based aqueous binder, deployed to ‘direct’ print Ti-6Al-4V powder with the achieved mechanical properties ranged between cortical and cancellous bone are described. The adopted process induced ~99% interconnectivity in the 3D microstructure, probed using quantitative micro-CT analysis. Finite Element-based analysis was developed to predict the stress-strain response of various designed porous architectures, while assigning an ‘effective’ material property obtained from microporous models without designed porosity.
In the broad second part of the thesis, the formulation of an in situ polymerisable acrylic binder/ink for printing implantable metallic biomaterials is highlighted. The modification of the printable Ti-6Al-4V powders using persulfate, allowed localised polymerisation during the 3D binderjet printing of with the on-demand deposited acrylic ink, In order to establish the theoretical perspective, Washburn’s theory was used to understand the transient kinetics of the ink/binder infiltration phenomena in ~100 µm thick powder bed layers,. The combinatorial experimental/analytical approaches enabled to predict the time required for the transient phenomena involved in binderjet printing. A pertinent combination of statistically reliable strength properties (Weibull modulus, compressive, flexural strength and compressive modulus of ~8, 222 MPa, 93 MPa and 4 GPa, respectively) of Ti-6Al-4V scaffolds was recorded along with ~98% interconnected microporous 3D microstructure. The cytocompatibility of the Ti-6Al-4V 3D architectures was established using mammalian fibroblasts and osteoblasts. In developing a better quantitative insight into ink infiltration kinetics, in the third part of this thesis, real time ink infiltration phenomena in the porous ceramic powder bed was investigated under high brilliance synchrotron X-Ray in refraction based phase contrast mode. An ethylene glycol-DI water based simulated ink was allowed to deposit ‘on-demand’ through a piezoelectric inkjet printhead and the post-impact ink infiltration behaviour through the porous alumina powder bed was captured real-time at a rate of 500 fps. Using a rigorous interactive image analysis, the real time wetting contours were extracted and penetration depth, lateral spread, transformed wetting volume was quantified. Denesuk and Holman’s models based on Washburn’s theory were adapted to develop a theoretical model of wetting volume in real time which was established to be dependent on powder bed porosity.
In the fourth part of this thesis, the experimental results related to the piezoelectric inkjet bioprinting of mammalian cells and the post-printing cell functionalities are demonstrated. Cell laden ‘printable’ bioink was printed through a 60 µm orifice printhead using three driving voltages of 80, 90 and 100 V at 3k Hz frequency. Post-printing proliferation (Alamar blue) of the cells was higher, when printed using higher voltage endorsing the positive effect of smooth and uninterrupted droplet ejectionat higher voltage. Propidium iodide (PI) and Texas red conjugated dextran based hierarchical set of molecular probes (3 kDa, 10 kDa, 40 kDa, and 70 kDa) were used to probe the post-printing cell membrane permeation in real time. An interesting observation is the cell membrane damage, which persisted only for few hours after the printing operation in lower voltage (80V). Importantly, the total area of pores and the maximum pore size are found to vary in accordance with the actuating voltage. As the viability and proliferation are uncompromised in higher printing voltage, the higher lifetime of the finite sized membrane pores can be potentially useful for intra-cellular molecular transfections like gene, protein deliveries for cell engineering applications.Department of Science and Technology (DST), Govt. of India, and particularly FIST funding; Department of Biotechnology ( DBT), Govt. of India; National Network for Mathematical and Computational Biology (NNMCB), SERB, Govt. of India; Commonwealth Scholarship Commission, UK; The cell printing and culture facility of Department of Materials, University of Manchester and Diamond Synchrotron facility (DLS, Oxfordshire), UK
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Fan, Wen-Hsuan, and 范文軒. "A Study of Critical Success Factors of 3D Printing Applied to Power Plants." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/26696949510238453305.
Повний текст джерелаАнотація:
碩士國立中興大學
資訊管理學系所
105
In response to the global green energy trends and the development of innovative technology, the use of 3D printing technology for the manufacture of energy-saving carbon reduction of energy facilities is gradually a growing trend. This study explores the relationship between the current status and the development trends of global renewable energy and the application of 3D printing technology through literature analysis and case study. According to analyze the meaning of the three relevant cases of 3D printing applications by using the PEST model and the expert interview method. We propose the critical success factors of 3D printing applied to power plants. The conclusions and recommendations of this paper are as follows: Industry, official, scholar and researcher should cooperate with each other to achieve "mutual link." The Government should formulate appropriate policies to promote the development of 3D printing technology in line with "cost-effective" power plants. At the same time the use of 3D printing technology features and advantages, combined with traditional manufacturing experiences and innovative applications to accelerate product development and commercialization, the revitalization of related industries, enhance the international market competitiveness.
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Song, Jiaxi. "Harnessing the power of light in nanopore sensing and biomedical 3D printing applications." Thesis, 2021. https://hdl.handle.net/2144/41888.
Повний текст джерелаАнотація:
Light is a ubiquitous form of energy used in many disciplines and industry sectors. Biomedical applications that harness the distinctive properties of light are rapidly growing in many areas, such as medical imaging, radiation therapy, and pathogen identification. This dissertation investigates two unique systems, in which the specific characteristics of light enable the single-molecule detection of fluorescently labeled polypeptides and the 3D printing of hydrogel-based cellular scaffolds and nasopharyngeal swabs.
The first half of the dissertation presents a novel solid-state nanopore sensor that employs multicolor fluorescence detection to facilitate the discrimination of two polypeptides at a single-molecule level. Solid-state nanopore devices drilled in locally supported, free-standing TiO2 membranes exhibit exceptionally low photoluminescence in the visible spectral range under simultaneous excitation of multiple lasers. The significant reduction of the optical signal-to-background ratio enables the differentiation of a single fluorophore between two polypeptide populations, thus introducing future possibilities for optical based identification of more complex peptides and proteins in nanopores.
The second half of the dissertation focuses on an emerging micro- and nano-fabrication technique based on direct laser writing (DLW) via two-photon polymerization. An innovative two-photon DLW-patterned hydrogel system to modulate cell alignment and adhesion is reported. Variations in the laser writing speed in the fabrication process lead to polymerized structures with distinctive stiff and soft components, without changing the photoresist. On cell-adhesive hydrogels, the width of the alternating stiff and soft patterns dictates the degree of F-actin alignment in hMSCs. The addition of a second hydrogel with cell-repellent properties enables the selective adhesion and alignment of hMSCs on microstructures with both flat and curved features. Lastly, the development of a novel 3D-printed nasopharyngeal test swab during the COVID-19 pandemic is presented. The optimized swab designs demonstrate non-inferior mechanical stability and testing accuracy compared to existing commercial test swabs.
In summary, significant progress has been made in both nanopore-based optical sensing and DLW of microscale cellular scaffolds. Future work will enhance existing technologies in the detection of complex peptides and proteins and the fabrication of functional, biocompatible, and dissolvable 3D-printed scaffolds to enable their clinical applications in protein molecular biomarker diagnostics and stem-cell-derived regenerative tissues for the diagnosis and treatment of a wide range of diseases.2023-01-18T00:00:00Z