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Desenvolvimento de matéria-prima para impressão tridimensional a partir de rejeitos gemológicos de ágatasIpar, Carlos Edmundo de Abreu e Lima January 2011 (has links)
A indústria de pedras preciosas de Soledade/RS e região gera em seus processos de beneficiamento grande quantidade de rejeitos gemológicos, que acabam sendo depositados nos pátios das empresas, podendo causar danos ao meio ambiente. A gema de maior volume de beneficiamento na região é a ágata. Este trabalho propõe uma técnica para efetuar a reutilização de rejeitos oriundos do beneficiamento da ágata e transformá-los em matériaprima para a fabricação de objetos via impressão tridimensional a jato de tinta (3DP). Através da utilização de metodologia adequada para moagem e classificação dos rejeitos, foi possível obter pó com granulometria adequada ao processo. Foram efetuadas duas formulações de matéria-prima, utilizando o método de aglutinação orgânico, com material de ligação misturado ao pó e líquido de deposição reologicamente simples. Foram efetuados testes de bancada para interação entre o pó e o aglutinante, testes em equipamento de prototipagem rápida e confecção de corpos de prova, que mais tarde foram submetidos a medição e ensaios de resistência mecânica à flexão a 4 pontos. Das análises efetuadas, a primeira formulação não foi considerada satisfatória, pois teve grandes deformações durante a construção e manipulação e pós-tratamento. Já a segunda formulação alcançou a mesma resistência mecânica do material disponibilizado pelo fabricante, com coerência nas formas geométricas e desvios dimensionais reduzidos. Com a utilização desta nova matéria-prima, estima-se que o custo final de fabricação das peças seja reduzido em até 70%, viabilizando a utilização do processo por empresas de micro e pequeno porte. / The gem processing industries of Soledade/RS and region generate a large amount of waste which is eventually deposited in the companies’ grounds and may damage the environment. The gem with largest volume of processing in the region is the agate. This work is a review of the reuse of wastes of agate as raw materials for inkjet three-dimensional printing (3DP). Through the use of appropriate methodology for grinding and classification of waste it was possible to obtain powder with a particle size indicated to the process. Two formulations of raw material were made, using the organic binding method with the binder material mixed into the powder and using the deposition simple rheological liquid. Bench tests were performed for powder binder interaction, and equipment was used for produce of test specimens which were later subjected to measurement and testing of mechanical strength. Based on the analysis the first formulation was not considered acceptable as it had large deformations during construction, manipulation and post-treatment. The second formulation reached the same mechanical strength of the manufacturer material with consistency in geometric shapes and dimensional deviation. Using this new raw material the estimated final cost of parts manufacturing is reduced by 70% making the use of the process available to micro and small businesses.
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Influência dos compostos na manufatura por impressão 3Dprinter no comportamento mecânico biomodelos / Influence of compounds in printing manufacturing 3Dprinter in biomodelos mechanical behaviorSales, Nicolas Coelho [UNESP] 31 August 2017 (has links)
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Previous issue date: 2017-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Na medicina atual, uma técnica destaca-se cada vez mais, a biomodelagem. Esta técnica consiste na construção de um biomodelo físico a partir de imagens bidimensionais (de tomografias, ressonâncias, ultrassom), que são tratadas e através de softwares transformadas em um biomodelo virtual que por fim torna-se um biomodelo físico, impresso por uma impressora tridimensional, possibilitando a equipe médica, a percepção de detalhes dificilmente observados apenas através de imagens bidimensionais. Porém o material importado utilizado na biomodelagem é de custo elevado. Neste trabalho o objetivo foi através de uma formulação tida como ideal, publicada no artigo de (Meira), variar as porcentagens de sua composição, o ligante utilizado, o método de mistura, as granulometrias dos pós e adicionar um novo constituinte (sulfato de magnésio), e assim, adquirir um material mais barato e observar qual a influência da composição e granulometria em propriedades fundamentais para a qualidade de um pó para manufatura aditiva, tais como fluidez para distribuição homogênea, alto empacotamento das partículas para maximizar a densidade das peças, espessura da camada maior que as dimensões dos aglomerados e bom acabamento superficial após a camada ser depositada. Posteriormente, foram produzidos corpos de prova com diferentes composições, granulometrias e submetidos a ensaios de compressão e flexão três pontos. Após estes ensaios, médias e desvios padrões foram calculados para cada composição e granulometria. Por fim, a composição que apresentou os melhores resultados foi comparada ao material importado atualmente utilizado. O novo material, com custo de produção por volta de dez vezes menor, atendou às necessidades mecânicas que um biomodelo exige, como por exemplo, resistência mínima ao manuseio. / In modern medicine, a technique that stands out increasingly is biotemplating. This technique involves the construction of a physical biomodel from two-dimensional images (tomography, resonance, ultrasound) which are handled and by software processed in a virtual biomodel which eventually becomes a physical biomodel printed by the 3D printer, allowing the medical team, the perception of details hardly observed through two-dimensional images. However the material used in the imported biotemplating is relatively expensive. In this work the aim was through regarded as optimum formulation published in the article (Meira, 2013) vary the percentages of composition (and adding a new constituent, magnesium sulfate), the binder used, the mixing method and granulometry of powders, and thus acquire a more inexpensive material and understand which influences the composition and granulometry properties essential to the quality of a powder additive manufacturing, such as flowability for homogeneous distribution, higher packing of the particles to maximize the density of manufactured, thickness of the layer higher than the dimensions of the agglomerates and good surface finish after the layer is deposited. Later, produced specimens with different compositions and particle sizes, and subjected them to compression tests and bending three points. After these tests, averages and standard deviations were calculated for each composition and grain size. Finally, the best results were compared to the imported material currently used. The new material, with a cost around ten times lower, meets the mechanical requirements that a biomodel requires, for example, minimum handling strength.
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Desenvolvimento de matéria-prima para impressão tridimensional a partir de rejeitos gemológicos de ágatasIpar, Carlos Edmundo de Abreu e Lima January 2011 (has links)
A indústria de pedras preciosas de Soledade/RS e região gera em seus processos de beneficiamento grande quantidade de rejeitos gemológicos, que acabam sendo depositados nos pátios das empresas, podendo causar danos ao meio ambiente. A gema de maior volume de beneficiamento na região é a ágata. Este trabalho propõe uma técnica para efetuar a reutilização de rejeitos oriundos do beneficiamento da ágata e transformá-los em matériaprima para a fabricação de objetos via impressão tridimensional a jato de tinta (3DP). Através da utilização de metodologia adequada para moagem e classificação dos rejeitos, foi possível obter pó com granulometria adequada ao processo. Foram efetuadas duas formulações de matéria-prima, utilizando o método de aglutinação orgânico, com material de ligação misturado ao pó e líquido de deposição reologicamente simples. Foram efetuados testes de bancada para interação entre o pó e o aglutinante, testes em equipamento de prototipagem rápida e confecção de corpos de prova, que mais tarde foram submetidos a medição e ensaios de resistência mecânica à flexão a 4 pontos. Das análises efetuadas, a primeira formulação não foi considerada satisfatória, pois teve grandes deformações durante a construção e manipulação e pós-tratamento. Já a segunda formulação alcançou a mesma resistência mecânica do material disponibilizado pelo fabricante, com coerência nas formas geométricas e desvios dimensionais reduzidos. Com a utilização desta nova matéria-prima, estima-se que o custo final de fabricação das peças seja reduzido em até 70%, viabilizando a utilização do processo por empresas de micro e pequeno porte. / The gem processing industries of Soledade/RS and region generate a large amount of waste which is eventually deposited in the companies’ grounds and may damage the environment. The gem with largest volume of processing in the region is the agate. This work is a review of the reuse of wastes of agate as raw materials for inkjet three-dimensional printing (3DP). Through the use of appropriate methodology for grinding and classification of waste it was possible to obtain powder with a particle size indicated to the process. Two formulations of raw material were made, using the organic binding method with the binder material mixed into the powder and using the deposition simple rheological liquid. Bench tests were performed for powder binder interaction, and equipment was used for produce of test specimens which were later subjected to measurement and testing of mechanical strength. Based on the analysis the first formulation was not considered acceptable as it had large deformations during construction, manipulation and post-treatment. The second formulation reached the same mechanical strength of the manufacturer material with consistency in geometric shapes and dimensional deviation. Using this new raw material the estimated final cost of parts manufacturing is reduced by 70% making the use of the process available to micro and small businesses.
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Loading Mode Dependent Effective Properties of Octet-truss Lattice Structures Using 3D-PrintingChallapalli, Adithya 05 1900 (has links)
Cellular materials, often called lattice materials, are increasingly receiving attention for their ultralight structures with high specific strength, excellent impact absorption, acoustic insulation, heat dissipation media and compact heat exchangers. In alignment with emerging additive manufacturing (AM) technology, realization of the structural applications of the lattice materials appears to be becoming faster. Considering the direction dependent material properties of the products with AM, by directionally dependent printing resolution, effective moduli of lattice structures appear to be directionally dependent. In this paper, a constitutive model of a lattice structure, which is an octet-truss with a base material having an orthotropic material property considering AM is developed. In a case study, polyjet based 3D printing material having an orthotropic property with a 9% difference in the principal direction provides difference in the axial and shear moduli in the octet-truss by 2.3 and 4.6%. Experimental validation for the effective properties of a 3D printed octet-truss is done for uniaxial tension and compression test. The theoretical value based on the micro-buckling of truss member are used to estimate the failure strength. Modulus value appears a little overestimate compared with the experiment. Finite element (FE) simulations for uniaxial compression and tension of octet-truss lattice materials are conducted. New effective properties for the octet-truss lattice structure are developed considering the observed behavior of the octet-truss structure under macroscopic compression and tension trough simulations.
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Performance of Rapid Tooling Molds for Thermoformed SocketsChimento, Jairo R 25 March 2009 (has links)
Traditional prosthetic socket fabrication is a laborious and time consuming process that involves physical measurements, plaster wrapping of the stump, plaster casting for positive mold preparation, and a thermoforming process. During the mold preparation stage, significant modifications are performed subjectively based on the prosthetist's experience to transmit an optimum load to the residual limb through the socket. Rapid Prototyping techniques have advanced rapidly during the recent decades emerging as a computer aided socket design alternative which promises a potential reduction in the fabrication time, and a more systematic design approach. In addition, 3-D scanning provides accurate and fast virtual replica of the stump which can be imported in CAD environments. Within 3-D CAD software, prosthetists are able to perform modifications precisely and store files indefinitely. This work examines the potential use of ZCorp 3-D printers to directly manufacture the thermoforming mold required for prosthetic socket manufacture. This work analyses the performance of Rapid Tooling molds for thermoformed socket based on three main parameters: pneumatic permeability, flexural strength and wear rate. The traditional material for mold casting, Plaster of Paris, is compared to materials used for three dimensional printing by Zcorp printers: zp130 and zp140 untreated as well as using them with custom and novel post treatments. To obtain the flexural strength of the different materials, three point bend tests were performed in a universal test machine using ASTM Standard D790-03 requirements. In addition, pneumatic permeability tests were performed to cylindrical specimens of the different materials following ASTM Standard D6539-00. Thermoforming tests confirm that Zcorp 3-D printed parts can serve as effective molds for thermoforming of prosthetic socket.
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Soft actuator and agile soft robotXia, Boxi January 2022 (has links)
Robots play an important part in many aspects of our society by doing repetitive, dangerous, or precision tasks. Most existing robots are made of rigid components, which lack passive compliance and pose a challenge in adapting to the environment and safe human-robot interaction. Rigid robots may be equipped with sensors and programmed with proprioceptive feedback control to achieve active compliance, but this may fail in the event of unforeseen situations or sensor failure.
In contrast, animals have evolved flexible or soft body parts to help them adapt to changing environments. Soft robotics is an emerging field in robotics, drawing inspiration from nature by integrating soft material into the actuator and mechanical design. With the inclusion of soft material, soft actuators and robots can deform actively/passively, making it possible to sense, absorb impact, and adapt to its environment with deformation. However, while soft actuators/robots have superior properties to rigid ones, they are often challenging to manufacture and control precisely. In addition, they may suffer from slow speed and material degradation. Thus, in this thesis, we aim to address the issues in developing high-performance soft actuators and soft robots.
The thesis is divided into two parts. In the first part, we focus on improving the manufacturability and performance of a self-contained soft actuator originated in the Creative Machines Lab. The soft actuator is composed of a cured silicone-ethanol mixture embedded with heating coils. When the coils are electrically actuated, ethanol trapped inside undergoes liquid-vapor transitions, and thus the actuator undergoes extreme volume change. While this actuator exhibits high strain and high stress, it is very slow to actuate, has limited life cycles, and requires molds to manufacture.
The first part of the thesis will address these issues. Specifically, in chapter 2, we discuss using multi-material 3D printing to automate the manufacturing of silicone-ethanol composite. In chapter 3, we discuss using laser-cut flexible Kirigami patterns to improve the manufacturability of its heating element. Chapter 4 characterizes its actuation profile and addresses improvements to the thermal conductivity by infusing thermally conductive fillers.
Soft actuation is an actively researched area; however, many high-performance soft actuators are challenging to manufacture and thus are less accessible to the general robotics community. Conventional actuators such as electric motors are widely available but lack flexibility. Therefore, the second part of the thesis aims at combining rigid motors with soft materials to design and control high-performance hybrid soft robots. Simulation is a good way to evaluate and optimize robot design and control. However, existing simulators that support motor-driven soft robots have limited features. Chapter 5 discusses this issue and presents a physically based real-time soft robot simulator capable of simulating motor-driven soft robots. In addition, chapter 5 presents the design and control of a 3D printed hybrid soft quadruped robot. Chapter 6 presents the design and control of a 3D printed hybrid soft humanoid robot.
The two parts of the thesis aim to improve aspects in soft actuators and soft robots. In conclusion, we summarize the lessons learned in developing soft actuators/robots and new possibilities and challenges for advancing soft robotics research.
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Rapid Prototyping in Design Education: A Comparative Study of Rapid Prototyping and Traditional Model ConstructionGreenhalgh, Scott D. 01 May 2009 (has links)
To evaluate the effectiveness of a rapid prototyping into a curriculum, a study was conducted requiring students to conceive a design and create a model. Students were randomly selected to be given access to the rapid prototype or to create the models by hand. The students' models were evaluated on scale, design, and craftsmanship. Students participated in a survey consisting of perceptions of design feedback and difficulties as well as interests and affective traits. The study utilized qualitative data investigating the instructors' perceptions prior to implementing rapid prototyping into the curriculum and its correlation to observed events. The study found statistical differences in scale and craftsmanship scores, as well as monetary and time investments with rapid prototyping producing better models at a higher cost with less time invested. The data also suggested rapid prototyping changed the design process as well as shifting affective dispositions within the project.
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Geometry and Plaque Morphology of the Superficial Femoral Artery with Clinical ImplicationsBishop, Paul D. January 2019 (has links)
No description available.
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Evaluation of a Patient-Specific, Low-Cost, 3-Dimensional–Printed Transesophageal Echocardiography Human Heart PhantomMeineri, Massimiliano 02 November 2021 (has links)
Simulation based education has been shown to increase the task-specific capability of medical trainees. Transesophageal echocardiography training greatly benefits from the use of simulators. They allow real time scanning of a beating heart and generation of ultrasound images side by side with anatomically accurate virtual model. These simulators are costly and have many limitations. 3D printing technologies have enabled the creation of bespoke phantoms capable of being used as task-trainers. This study aims to compare the ease of use and accuracy of a low-cost patient-specific, Computer-tomography based, 3D printed, echogenic TEE phantom compared to a commercially available echocardiography training mannequin.
We hypothesized that a low-cost, 3D printed custom-made, cardiac phantom has comparable image quality, accuracy and usability as existing commercially available echocardiographic phantoms.
After Institutional Ethic Research Board approval, we recruited ten American Board – Certified cardiac anesthesiologists and conducted a blinded comparative study divided into two stages. Stage one consisted of image assessment. A set of basic TEE views obtained from the 3D printed and commercial phantom were presented to the participants on a computer screen in random order. For each image, participants will be asked to identify the view, identify the quality of the image on a 1-5 Likert scale compared to the corresponding human view and guess with which phantom it was acquired (1 not at all realistic to patients view and 5 realistic to patients view). Stage two, participants will be asked to use the 3D printed and the commercially available phantom to obtain basic TEE views. In a maximum of 30 minutes. Each view was recorded and assessed for accuracy by two certified echocardiographers. Time needed to acquire each basic view and number of correct views was recorded. Overall usability of the phantoms was assessed through a questionnaire. For all continuous variables, we will calculate mean, median and standard deviation. We use Wilcoxon Signed-Rank test to assess significant differences in the rating of each phantom.
All ten participants completed all part of the study. All participants could recognize all of the standard views. The average Likert scale was 3.2 for the 3D printed and 2.9 for the commercial Phantom with no significant difference. The average time to obtain views was 24.5 and 30 sec for the 3D printed and the commercial phantoms respectively statistically significantly in favor of the 3D printed phantom. The qualitative user assessment for ease to obtain the views, probe manipulation, image quality and overall experience were in great favor of the 3D printed phantom.
Our Study suggest that the quality of TEE images obtained on the 3D printed phantom are not significantly different from those obtained on the commercial Phantom. The ease of use and time required to complete a basic TEE exam were in favor of the 3D Printed phantom.:Table of Content
1. Bibliographic Description 3
2. Introduction 4
2.1. Perioperative transesophageal echocardiography 4
2.2. Transesophageal echocardiography training 5
2.3. Transesophageal echocardiography simulation 6
2.4. 3D Heart Printing 13
2.5. 3D Segmentation 16
2.6. Development of the study phantom 17
2.7. Study Rationale 18
3. Publication 22
4. Summary 30
5. References 33
6. Appendices 37
6.1. Darstellung des eigenes Beitrags 38
6.2. Erklärung über die eigenständige Abfassung der Arbeit 39
6.3. Lebenslauf 40
6.4. Publikationen und Vorträge 44
6.5. Danksagung 61
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Analysis of accuracy and mechanical properties of 3D-printed polymeric dental materialsAlshaibani, Raghdah Mohammedali 28 May 2024 (has links)
OBJECTIVES: The objective was to investigate the accuracy, storage stability, and
mechanical properties of 3D-printed polymeric dental materials.
MATERIALS AND METHODS: Three completely dentate models, two maxillary and one
mandibular each with their respective die, and three implant models were designed using
dental CAD software (3SHAPE DENTAL SYSTEM). A horseshoe-shaped solid base with
a posterior horizontal bar was utilized. The models were printed based on the
manufacturer's instructions for four weeks using six printers with the corresponding
recommended resin materials: Carbon M2 (DPR10), HeyGears A2D4K (Model HP
UV2.0), Stratasys J5 (MED610), Stratasys Origin One (DM200), Envision One (E-Model
LightDLP), and Asiga Pro4K (VeriModel) with a standard layer thickness of 50 μm
(N=72). The models were scanned after printing using Sirona inEOS X5 scanner, while the implant models were scanned using a CT scanner (GE Phoenix V|tome|x metrology edition). The full arch models were randomly assigned to three groups of storage conditions: cold environment (LT, 4 ± 1°C), hot and dry environment (HT, 50 ± 2°C), and
room temperature (RT , 25 ± 2°C, serving as the control). Each group was kept under the
designated conditions and scanned at 1, 2, 3, 4, and 8 weeks. The generated STL files were
imported into a 3D inspection software for comparison with the original STL files. Four
sets of reference points (central fossa of first premolars and central fossae of second molars)
were selected to determine six distances of inter-arch segments, from which the inter-arch
distance trueness and precision deviation were measured.
For the second part of the study, maxillary Lucitone Digital Print denture base (DB) (N=5),
maxillary Lucitone IPN 3D Premium anterior and posterior teeth (N=6), and maxillary
Keystone Keysplint Soft Clear occlusal splint (N=5) were printed using two printers
(Carbon M2, Asiga Max UV) with a standard layer thickness of 50 μm for denture base
and teeth, and 100 μm for the occlusal splint. The tolerance threshold was set to 50 μm for
Lucitone IPN and 100 μm for Lucitone DB and Keysplint Soft. In-tolerance percentage
and deviation RMS were obtained and analyzed with multivariate least square mean linear
regression using JMP Pro 17 (SAS, Cary, NC) to identify significant effects (α=0.05).
The third part investigated the mechanical properties of Lucitone DB and IPN using 2
printers (Carbon M2, Asiga Max UV) as follows: flexural strength (N=10) using a threepoint
bend test, fracture toughness (N=10), creep (N=5), Vickers hardness test (N=15),
surface roughness (N=15), while Shore A hardness (N=15) and tensile strength (N=10)
were performed for Keysplint Soft Clear. Data were analyzed using one-way and multivariate least square mean linear regression followed by Tukey’s HSD test using JMP Pro 17 (SAS, Cary, NC) to identify significant effects (α=0.05).
RESULTS: The in-tolerance percentage varied significantly among printers, with Carbon M2
(CAB) showing the highest values. Stratasys (J5) displayed the highest accuracy in term of
precision, while HeyGears A2D4K (HGS), Carbon M2 (CAB), and Stratasys (J5) exhibited
the highest accuracy in term of trueness. The inter-molar segment showed the highest
deviation. No significant difference was observed in in-tolerance percentage across
different print weeks except for week 2 in one printer (Stratasys Origin1). CAB exhibited
a higher in-tolerance percentage for the DB than Asiga Max UV (ASG), with the fitting
surface having the highest in-tolerance percentage. IPN anterior teeth had a higher intolerance
percentage than posterior teeth, with ASG showing a higher value than CAB. No
statistically significant difference was found in the in-tolerance percentage of Keysplint
Soft Clear between ASG and CAB. Resin printed using ASG demonstrated higher flexural
strength, Vickers hardness, and creep, while resin printer using CAB exhibited higher
fracture toughness, with no significant difference in surface roughness between the two
printers. Lucitone IPN had higher flexural strength and Vickers hardness, surface
roughness , and lower creep and fracture toughness than Lucitone DB. CAB Keysplint
Soft had higher tensile strength than ASG, with no statistically significant difference in
Shore A hardness between the two printers.
CONCLUSION: Model dimension deviations were impacted by storage conditions and the
specific printer utilized, with high-temperature storage exhibiting the least stability.
However, no significant difference was noted between low and room temperature storage
conditions. Carbon M2 exhibited the highest level of accuracy. The of 3D-printed denture
bases and denture teeth varied across different printers. Conversely, no significant
difference in accuracy was observed for a soft occlusal splint between two printers.
Materials printed using different printers showed statistically significant different
mechanical properties.
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