scholarly journals Additive Manufacturing in Customized Medical Device

2021 ◽  
Author(s):  
Ching Hang Bob Yung ◽  
Lung Fung Tse ◽  
Wing Fung Edmond Yau ◽  
Sze Yi Mak
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Medical Device ◽  
Three Dimensional ◽  
Medical Industry ◽  
New Era ◽  
Medical Needs ◽  
3D Printed ◽  
Traditional Manufacturing

The long-established application of rapid prototyping in additive manufacturing (AM) has inspired a revolution in the medical industry into a new era, in which the clinical-driven development of the customized medical device is enabled. This transformation could only be sustainable if clinical concerns could be well addressed. In this work, we propose a workflow that addresses critical clinical concerns such as translation from medical needs to product innovation, anatomical conformation and execution, and validation. This method has demonstrated outstanding advantages over the traditional manufacturing approach in terms of form, function, precision, and clinical flexibility. We further propose a protocol for the validation of biocompatibility, material, and mechanical properties. Finally, we lay out a roadmap for AM-driven customized medical device innovation based on our experiences in Hong Kong, addressing problems of certification, qualification, characterization of three dimensional (3D) printed implants according to medical demands.

Study of Printing Orientation on Mechanical Properties in Additive Manufacturing Process

2019 ◽  
Author(s):  
Peyman Honarmandi ◽  
Hongbin Xu
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Young’S Modulus ◽  
Manufacturing Process ◽  
Young's Modulus ◽  
Innovative Technology ◽  
Build Orientation ◽  
Fused Deposition ◽  
3D Printed

Abstract Additive manufacturing (AM) is an innovative technology that creates parts by adding small portions of materials layer by layer, which frees designers to create parts that were not possible to manufacture with subtractive manufacturing processes previously. This led to wide-spread popularity of 3D-printing technology. In this technology. fused deposition modeling (FDM) is the most affordable one in the market now. Therefore, it is vital to understand how the print orientation, which can be customized very easily, affects the mechanical properties of the prints to maximize the strength of the product. This paper aims to present the methodology and results of the experimental characterization of the acrylonitrile butadiene styrene (ABS) 3D-printed part. Tensile characterization of ABS was performed to analyze anisotropic nature of 3D-printed parts caused by its unique manufacturing process. Specimens were printed with six different configurations: four raster ([45/−45], [30/−60], [15/−75] and [0/90]) and three build orientations (0 or flat, 45, and 90 degrees with respect to the build plate, all printed in [45/−45] raster orientation). Dogbone tensile specimens were printed and pulled using the tensile test machine. The young’s modulus, yield strength, ultimate strength, strain at failure, breaking strength were found for each configuration. As the build orientation angle increased and the raster orientation goes from [45/−45] to [0/90], mechanical properties decreased steadily except the Young’s modulus. For build orientation, Young’s modulus decreased first then increased as angle increased, and for the raster orientation, there was no statistically significant difference as raster changed from [45/−45] to [0/90]. Overall, [45/−45] flat configuration is the strongest and the most stable configuration.

Anisotropic Material Behaviors of 3D Printed Carbon-Fiber Polymer Composites With Open-Source Printers

2021 ◽  
Author(s):  
Jordan Garcia ◽  
Robert Harper ◽  
Y. Charles Lu
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Carbon Fiber ◽  
3D Printing ◽  
Open Source ◽  
Polymer Composites ◽  
Mechanical Responses ◽  
Manufacturing Technique ◽  
3D Printed ◽  
Traditional Manufacturing

Abstract Composite products are often created using traditional manufacturing methods such as compression or injection molding. Recently, additive manufacturing (3D printing) techniques have been used for fabricating composites. 3D printing is the process of producing three-dimensional parts through the successive combination of various layers of material. This layering effect in combination with exposure to ambient (or reduced) temperature and pressure cause the finished products to have inconsistent microstructures. The inconsistent microstructures along with the oriented reinforcing fibers create anisotropic parts with difficulty to predict mechanical properties. In this paper, the mechanical properties of fiber reinforced polymer composites produced by additive manufacturing technique (3D printing) and by traditional manufacturing technique (compression molding) were investigated. Three open-source 3D printers, i.e. FlashForge Dreamer, Tevo Tornado, and Prusa i3 Mk3, were used to fabricate bending samples from carbon-fiber reinforced ABS (acrylonitrile butadiene styrene). Results showed that there exist significant discrepancies and anisotropies in mechanical properties of 3D printed composites. First, the properties vary greatly among parts made from different printers. Secondly, the mechanical responses of 3D printed parts strongly depend upon the orientations of the filaments. Parts with the infill oriented along the length of the specimens showed the most favorable mechanical responses such as Young’s modulus, maximum strength, and toughness. Thirdly, all 3D printed parts exhibit inferior properties to those made by conventional manufacturing. Finally, theoretical modeling has been attempted to predict the mechanical responses of 3D printed products and can potentially be used to “design” the 3D printing processes to achieve the optimal performance.

scholarly journals Lightweight Microlattice With Tunable Mechanical Properties Using 3D Printed Shape Memory Polymer

2018 ◽  
Author(s):  
Chen Yang ◽  
Manish Boorugu ◽  
Andrew Dopp ◽  
Howon Lee
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Three Dimensional ◽  
Temperature Shift ◽  
Spatial Arrangement ◽  
Mechanical Metamaterials ◽  
3D Printed ◽  
Varying Environments

Metamaterials are architected artificial materials engineered to exhibit properties not typically found in natural materials. Increasing attention has recently been given to mechanical metamaterials with unprecedented mechanical properties including high stiffness, strength, or/and resilience even at extremely low density. These unusual mechanical performances emerge from the three-dimensional (3D) spatial arrangement of the micro-structural elements designed to effectively distribute mechanical loads. Recent advances in additive manufacturing in micro-/nano-scale have catalyzed the growing interest in this field. This work presents a new lightweight microlattice with tunable and recoverable mechanical properties using a three-dimensionally architected shape memory polymer (SMP). SMP microlattices were fabricated utilizing our micro additive manufacturing technique called projection micro-stereolithography (PμSL), which uses a digital micro-mirror device (DMD™) as a dynamically reconfigurable photomask. We use a photo-crosslinkable and temperature-responsive SMP which can retain its large deformation until heated for spontaneous shape recovery. In addition, it exhibits remarkable elastic modulus changes during this transition. We demonstrate that mechanical responses of the micro 3D printed SMP microlattice can be reversibly tuned by temperature control. Mechanical testing result showed that stiffness of a SMP microlattice changed by two orders of magnitude by a moderate temperature shift by 60°C. Furthermore, the shape memory effect of the SMP allows for full restitution of the original shape of the microlattice upon heating even after substantial mechanical deformation. Mechanical metamaterials with lightweight, reversibly tunable properties, and shape recoverability can potentially lead to new smart structural systems that can effectively react and adapt to varying environments or unpredicted loads.

ANISOTROPIC MATERIAL BEHAVIORS OF 3D PRINTED CARBON-FIBER POLYMER COMPOSITES WITH OPEN-SOURCE PRINTERS

2021 ◽  
pp. 1-8
Author(s):  
Jordan Garcia ◽  
Robert Harper ◽  
Y. Charles Lu
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Carbon Fiber ◽  
3D Printing ◽  
Open Source ◽  
Polymer Composites ◽  
Mechanical Responses ◽  
Manufacturing Technique ◽  
3D Printed ◽  
Traditional Manufacturing

Abstract Composite products are often created using traditional manufacturing methods such as compression or injection molding. Recently, additive manufacturing (3D printing) techniques have been used for fabricating composites. 3D printing is the process of producing three-dimensional parts through the successive combination of various layers of material. This layering effect in combination with exposure to ambient (or reduced) temperature and pressure cause the finished products to have inconsistent microstructures. The inconsistent microstructures along with the oriented reinforcing fibers create anisotropic parts with difficulty to predict mechanical properties. In this paper, the mechanical properties of fiber reinforced polymer composites produced by additive manufacturing technique (3D printing) and by traditional manufacturing technique (compression molding) were investigated. Three open-source 3D printers, i.e. FlashForge Dreamer, Tevo Tornado, and Prusa i3 Mk3, were used to fabricate bending samples from carbon-fiber reinforced ABS (acrylonitrile butadiene styrene). Results showed that there exist significant discrepancies and anisotropies in mechanical properties of 3D printed composites. First, the properties vary greatly among parts made from different printers. Secondly, the mechanical responses of 3D printed parts strongly depend upon the orientations of the filaments. Parts with the infill oriented along the length of the specimens showed the most favorable mechanical responses such as Young's modulus, maximum strength, and toughness. Thirdly, all 3D printed parts exhibit inferior properties to those made by conventional manufacturing. Finally, theoretical modeling has been attempted to predict the mechanical responses of 3D printed products and can be used to “design” the 3D printing processes.

Qualität von additiv hergestellten PLA-Bauteilen*/Quality of additively manufactured PLA components – How the print direction influences the mechanical properties and the distortion of 3D-printed PLA components

2018 ◽  
Vol 108 (06) ◽  
pp. 419-425
Author(s):  
H. Möhring ◽  
T. Stehle ◽  
D. Becker ◽  
R. Eisseler
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Low Cost ◽  
Three Dimensional ◽  
Filling Ratio ◽  
Additive Fertigung ◽  
3D Printed

Die additive Fertigung eröffnet neue Gestaltungs- und Optimierungsfreiheitsgrade für oberflächen- und strukturoptimierte Bauteile. Mit diesen Verfahren lassen sich selbst komplexe räumliche Strukturen kostengünstig herstellen. Der vorliegende Artikel untersucht den Einfluss der Druckrichtung und des Füllgrads auf die mechanischen Eigenschaften, den Verzug sowie die erreichbaren Formgenauigkeiten am Beispiel von mit 3D-Druck über den FDM-Prozess erzeugten PLA-Bauteilen.   Additive manufacturing opens up new possibilities for optimizing components with regard to surfaces and structures. These processes allow producing even the most complex three-dimensional structures at comparatively low cost. This paper analyzes how the print direction and the filling ratio affect the mechanical properties, the distortion, as well as the achievable geometrical accuracies, by using 3D-printed PLA components produced by FDM processes.

Animal orthosis fabrication with additive manufacturing – a case study of custom orthosis for chicken

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wiktoria Maria Wojnarowska ◽  
Jakub Najowicz ◽  
Tomasz Piecuch ◽  
Michał Sochacki ◽  
Dawid Pijanka ◽  
...  
Keyword(s):  
Veterinary Medicine ◽  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Content Type ◽  
Fused Deposition ◽  
Secondary Objective ◽  
Traditional Manufacturing ◽  
Aided Design

Purpose Chicken orthoses that cover the ankle joint area are not commercially available. Therefore, the main purpose of this study is to fabricate a customised temporary Ankle–Foot Orthosis (AFO) for a chicken with a twisted ankle using computer-aided design (CAD) and three-dimensional (3D) printing. The secondary objective of the paper is to present the specific application of Additive Manufacturing (AM) in veterinary medicine. Design/methodology/approach The design process was based on multiple sketches, photos and measurements that were provided by the owner of the animal. The 3D model of the orthosis was made with Autodesk Fusion 360, while the prototype was fabricated using fused deposition modelling (FDM). Evaluation of the AFO was performed using the finite element method. Findings The work resulted in a functional 3D printed AFO for chicken. It was found that the orthosis made with AM provides satisfactory stiffen and a good fit. It was concluded that AM is suitable for custom bird AFO fabrication and, in some respects, is superior to traditional manufacturing methods. It was also concluded that the presented procedure can be applied in other veterinary cases and to other animal species and other parts of their body. AM provides veterinary with a powerful tool for the production of well-fitted and durable orthoses for animals. Research limitations/implications The study does not include the chicken's opinion on the comfort or fit of the manufactured AFO due to communication issues. Evaluation of the final prototype was done by the researchers and the animal owner. Originality/value No evidence was found in the literature on the use of AM for chicken orthosis, so this study is the first to describe such an application of AM. In addition, the study demonstrates the value of AM in veterinary medicine, especially in the production of devices such as orthoses.

Additive technology applied to the realization of K-band microwave terminations: reproducibility improvement

2018 ◽  
Vol 10 (1) ◽  
pp. 3-8
Author(s):  
Azar Maalouf ◽  
Ronan Gingat ◽  
Vincent Laur
Keyword(s):  
3D Printing ◽  
Frequency Band ◽  
Rectangular Waveguide ◽  
Three Dimensional ◽  
Low Density ◽  
Support Material ◽  
Additive Technology ◽  
3D Printed ◽  
K Band

This study examines K-band rectangular waveguide terminations with three-dimensional (3D)-printed loads, and proposes an Asymmetrical Tapered Wedge topology. This geometry shows a good tradeoff between microwave performance and 3D-printing issues (printing directions and support material requirements), thus improving noticeably the reproducibility of the devices. The effect of the density of the 3D-printed load on the reflection parameter of the termination was investigated. Even for a low density, reflection level remained below −27.5 dB between 18 and 26.5 GHz. Reproducibility was demonstrated by the characterization of six loads that were 3D printed under the same conditions. Measurements demonstrate that a maximum reflection parameter level of −33.5 dB can be ensured over the whole frequency band without any post-machining of the 3D-printed devices.

scholarly journals Effect of Porosity on Mechanical Properties of 3D Printed Polymers: Experiments and Micromechanical Modeling Based on X-Ray Computed Tomography Analysis

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1154 ◽  
Author(s):  
Wang ◽  
Zhao ◽  
Fuh ◽  
Lee
Keyword(s):  
Computed Tomography ◽  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Micromechanical Model ◽  
Micromechanical Modeling ◽  
X Ray ◽  
Fused Deposition ◽  
3D Printed ◽  
X Ray Computed

Additive manufacturing (commonly known as 3D printing) is defined as a family of technologies that deposit and consolidate materials to create a 3D object as opposed to subtractive manufacturing methodologies. Fused deposition modeling (FDM), one of the most popular additive manufacturing techniques, has demonstrated extensive applications in various industries such as medical prosthetics, automotive, and aeronautics. As a thermal process, FDM may introduce internal voids and pores into the fabricated thermoplastics, giving rise to potential reduction on the mechanical properties. This paper aims to investigate the effects of the microscopic pores on the mechanical properties of material fabricated by the FDM process via experiments and micromechanical modeling. More specifically, the three-dimensional microscopic details of the internal pores, such as size, shape, density, and spatial location were quantitatively characterized by X-ray computed tomography (XCT) and, subsequently, experiments were conducted to characterize the mechanical properties of the material. Based on the microscopic details of the pores characterized by XCT, a micromechanical model was proposed to predict the mechanical properties of the material as a function of the porosity (ratio of total volume of the pores over total volume of the material). The prediction results of the mechanical properties were found to be in agreement with the experimental data as well as the existing works. The proposed micromechanical model allows the future designers to predict the elastic properties of the 3D printed material based on the porosity from XCT results. This provides a possibility of saving the experimental cost on destructive testing.

Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Motion Direction ◽  
B Spline ◽  
And Topology ◽  
Printing System ◽  
3D Printed ◽  
Printed Patterns

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

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