scholarly journals Classification of X-Ray Attenuation Properties of Additive Manufacturing and 3D Printing Materials Using Computed Tomography From 70 to 140 kVp

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiangjie Ma ◽  
Martin Buschmann ◽  
Ewald Unger ◽  
Peter Homolka
Keyword(s):  
Adipose Tissue ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Energy Dependence ◽  
Fused Deposition Modeling ◽  
Soft Tissues ◽  
Diagnostic Image Quality ◽  
X Ray ◽  
Fused Deposition ◽  
Wide Range

Additive manufacturing and 3D printing is particularly useful in the production of phantoms for medical imaging applications including determination and optimization of (diagnostic) image quality and dosimetry. Additive manufacturing allows the leap from simple slab and stylized to (pseudo)-anthropomorphic phantoms. This necessitates the use of materials with x-ray attenuation as close as possible to that of the tissues or organs mimicked. X-ray attenuation properties including their energy dependence were determined for 35 printing materials comprising photocured resins and thermoplastic polymers. Prior to measuring x-ray attenuation in CT from 70 to 140 kVp, printing parameters were thoroughly optimized to ensure maximum density avoiding too low attenuation due to microscopic or macroscopic voids. These optimized parameters are made available. CT scanning was performed in a water filled phantom to guarantee defined scan conditions and accurate HU value determination. The spectrum of HU values covered by polymers printed using fused deposition modeling reached from −258 to +1,063 at 120 kVp (−197 to +1,804 at 70 kVp, to −266 to +985 at 140 kVp, respectively). Photocured resins covered 43 to 175 HU at 120 kVp (16–156 at 70, and 57–178 at 140 kVp). At 120 kVp, ASA mimics water almost perfectly (+2 HU). HIPS (−40 HU) is found close to adipose tissue. In all photocurable resins, and 17 printing filaments HU values decreased with increasing beam hardness contrary to soft tissues except adipose tissue making it difficult to mimic water or average soft tissue in phantoms correctly over a range of energies with one single printing material. Filled filaments provided both, the HU range, and an appropriate energy dependence mimicking bone tissues. A filled material with almost constant HU values was identified potentially allowing mimicking soft tissues by reducing density using controlled under-filling. The measurements performed in this study can be used to design phantoms with a wide range of x-ray contrasts, and energy dependence of these contrasts by combining appropriate materials. Data provided on the energy dependence can also be used to correct contrast or contrast to noise ratios from phantom measurements to real tissue contrasts or CNRs.

Design, Development and Characterization of Linear, Soft Actuators via Additive Manufacturing

2018 ◽  
Author(s):  
Alfonso Costas ◽  
Daniel E. Davis ◽  
Yixian Niu ◽  
Sadegh Dabiri ◽  
Jose Garcia ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Single Step ◽  
Design Development ◽  
Initial Attempt ◽  
Fused Deposition ◽  
Piston Cylinder ◽  
Compact Size ◽  
Soft Actuators

Additive manufacturing has emerged as an alternative to traditional manufacturing technologies. In particular, industries like fluid power, aviation and robotics have the potential to benefit greatly from this technology, due to the design flexibility, weight reduction and compact size that can be achieved. In this work, the design process and advantages of using 3D printing to make soft linear actuators were studied and highlighted. This work explored the limitations of current additive manufacturing tolerances to fabricate a typical piston-cylinder assembly, and how enclosed bellow actuators could be used to overcome high leakage and friction issues experienced with a piston-cylinder type actuator. To do that, different 3D printing technologies were studied and evaluated (stereolithorgraphy and fused deposition modeling) in the pursuit of high-fidelity, cost-effective 3D printing. The initial attempt consisted of printing the soft actuators directly using flexible materials in a stereolithography-type 3D printer. However, these actuators showed low durability and poor performance. The lack of a reliable resin resulted in the replacement of this material by EcoFlex® 00-30 silicone and the use of a 3D printed mold to cast the actuators. These molds included a 3-D printed dissolvable core inside the cast actuator in order to finish the manufacturing process in one single step. An experimental setup to evaluate the capabilities of these actuators was developed. Results are shown to assess the steady-state and the dynamic characteristics of these actuators. These tests resulted into the stroke-pressure and stroke-time responses for a specific load given different proportional valve inputs.

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.

Incorporation of fluorescent quantum dots for 3D printing and additive manufacturing applications

2018 ◽  
Vol 6 (28) ◽  
pp. 7584-7593 ◽  
Author(s):  
Cole D. Brubaker ◽  
Talitha M. Frecker ◽  
James R. McBride ◽  
Kemar R. Reid ◽  
G. Kane Jennings ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Quantum Dot ◽  
Fused Deposition Modeling ◽  
Fused Deposition ◽  
Cadmium Sulfur Selenide ◽  
Functionalized Materials ◽  
Deposition Modeling ◽  
Manufacturing Applications

3D printing of cadmium sulfur selenide quantum dot functionalized materials compatible with fused deposition modeling type processes and applications.

scholarly journals Experience of implementation in educational process modern technologies of FDM 3D printing

2021 ◽  
pp. 55-59
Author(s):  
Petr Andrienko ◽  
Vladimir Vasilevskij ◽  
Ivan Vittsivskyi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Current Transformer ◽  
Educational Process ◽  
Small Scale ◽  
Thermoplastic Material ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Modern Technologies

Fused Deposition Modeling is an additive manufacturing technology where a temperature-controlled head extrudes a thermoplastic material onto a build platform in a predetermined path. Standard, advanced thermoplastics and composites are used for printing. Among the areas of application for FDM printing, the main ones are rapid prototyping, as well as small-scale and batch production. The purpose of the work is the implementation of FDM 3D printing technology in the educational process of students in specialty 141 "Electroenergy, electrotechnics and electromechanics". The features of the technology of additive manufacturing of electrical apparatuses parts by the method of FDM printing have been investigated. Parts of four standard sizes were printed using ABS + and PLA plastics, namely, current transformer carcasses in the amount of 110 pieces and sensor bodies in the amount of 100 pieces. For printing, an FDM 3D printer was used built on the XZ Head Y Bed kinematic scheme with an open working chamber. The analysis of defects in finished products was carried out, which showed that the main defects are deviations of the actual dimensions and geometric shape of the finished products. Ways to prevent the occurrence of these defects are considered, namely, correcting the size of the model at the stage of preparing the model for printing, minimizing the filling density of the model, using brims in models, setting the optimal temperature of the working platform and simultaneously printing several products. The results of the study o features of the technology of additive manufacturing of electrical apparatuses parts by the method of FDM printing made it possible to develop a set of laboratory works for students of the specialty 141 "Electroenergy, electrotechnics and electromechanics".

scholarly journals Cellulose Nanofibrils Filled Poly(Lactic Acid) Biocomposite Filament for FDM 3D Printing

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2319 ◽  
Author(s):  
Qianqian Wang ◽  
Chencheng Ji ◽  
Lushan Sun ◽  
Jianzhong Sun ◽  
Jun Liu
Keyword(s):  
Thermal Stability ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Cellulose Nanofibrils ◽  
Poly Lactic Acid ◽  
Fused Deposition ◽  
Wide Range ◽  
The Matrix ◽  
Direct Digital Manufacturing

As direct digital manufacturing, 3D printing (3DP) technology provides new development directions and opportunities for the high-value utilization of a wide range of biological materials. Cellulose nanofibrils (CNF) and polylactic acid (PLA) biocomposite filaments for fused deposition modeling (FDM) 3DP were developed in this study. Firstly, CNF was isolated by enzymatic hydrolysis combined with high-pressure homogenization. CNF/PLA filaments were then prepared by melt-extrusion of PLA as the matrix and CNF as the filler. Thermal stability, mechanical performance, and water absorption property of biocomposite filaments and 3D-printed objects were analyzed. Findings showed that CNF increased the thermal stability of the PLA/PEG600/CNF composite. Compared to unfilled PLA FDM filaments, the CNF filled PLA biocomposite filament showed an increase of 33% in tensile strength and 19% in elongation at break, suggesting better compatibility for desktop FDM 3DP. This study provided a new potential for the high-value utilization of CNF in 3DP in consumer product applications.

scholarly journals 3D printers in dentistry: a review of additive manufacturing techniques and materials

2021 ◽  
Author(s):  
Leonardo Portilha Gomes da Costa ◽  
Stephanie Isabel Díaz Zamalloa ◽  
Fernando Amorim Mendonça Alves ◽  
Renan Spigolon ◽  
Leandro Yukio Mano ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Dental Materials ◽  
Clinical Results ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
3D Printers ◽  
Manufacturing Techniques ◽  
Printed Materials

3D printers manufacture objects used in various dental specialties. Objective: This literature review aims to explore different techniques of current 3D printers and their applications in printed materials for dental purposes. Methods: The online PubMed databases were searched aiming to find applications of different 3D printers in the dental area. The keywords searched were 3D printer, 3D printing, additive manufacturing, rapid prototyping, 3D prototyping, dental materials and dentistry. Results: From the search results, we describe Stereolithography (SLA), Digital Light Processing (DLP), Material Jetting (MJ), Fused Deposition Modeling (FDM), Binder Jetting (BJ) and Dust-based printing techniques. Conclusion: 3D printing enables different additive manufacturing techniques to be used in dentistry, providing better workflows and more satisfying clinical results.

scholarly journals 3D printing for clothing production

2020 ◽  
Vol 15 ◽  
pp. 155892502094821
Author(s):  
Tatjana Spahiu ◽  
Eriseta Canaj ◽  
Ermira Shehi
Keyword(s):  
3D Printing ◽  
Online Survey ◽  
Fused Deposition Modeling ◽  
Consumer Acceptance ◽  
Fashion Industry ◽  
3D Objects ◽  
Fused Deposition ◽  
Wide Range ◽  
Deposition Modeling ◽  
3D Printed

3D printing is a well-known technology for creating 3D objects by laying down successive layers of various materials. Among the wide range of applications, fashion industry has adapted these technologies to revolutionize their brands. But due to the unique characteristics of textiles like comfort, flexibility, and so on, attempts have been made to create similar structures as textiles. The work presented here is part of a project to create garments using fused deposition modeling as 3D printing technology. Structures with various geometries are designed and tested with different materials starting from rigid to flexible. As a result, a fully 3D printed dress is created. Selecting this dress as a model, consumer acceptance for 3D printed garments is evaluated realizing an online survey containing 100 respondents. The data gathered show that respondents have knowledge of 3D printing, its advantages and the majority of them would accept wearing a 3D printed dress.

Finite Element Analysis of Additive Manufacturing Based on Fused Deposition Modeling: Distortions Prediction and Comparison With Experimental Data

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Alberto Cattenone ◽  
Simone Morganti ◽  
Gianluca Alaimo ◽  
Ferdinando Auricchio
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Step Size ◽  
Time Step ◽  
Time Step Size ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
The Impact ◽  
Functional Components

Additive manufacturing (or three-dimensional (3D) printing) is constantly growing as an innovative process for the production of complex-shape components. Among the seven recognized 3D printing technologies, fused deposition modeling (FDM) covers a very important role, not only for producing representative 3D models, but, mainly due to the development of innovative material like Peek and Ultem, also for realizing structurally functional components. However, being FDM a production process involving high thermal gradients, non-negligible deformations and residual stresses may affect the 3D printed component. In this work we focus on meso/macroscopic simulations of the FDM process using abaqus software. After describing in detail the methodological process, we investigate the impact of several parameters and modeling choices (e.g., mesh size, material model, time-step size) on simulation outcomes and we validate the obtained results with experimental measurements.

scholarly journals 3D Printing of an Oil/Water Mixture Separator with In Situ Demulsification and Separation

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 774 ◽  
Author(s):  
Changyou Yan ◽  
Shuanhong Ma ◽  
Zhongying Ji ◽  
Yuxiong Guo ◽  
Zhilu Liu ◽  
...  
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Separation Efficiency ◽  
Water Mixture ◽  
Fused Deposition ◽  
Oil In Water ◽  
Wide Range ◽  
Hydrogel Coatings ◽  
Oil Water ◽  
Underwater Superoleophobicity

Currently, many meshes, membranes, and fabrics with extreme wettability of superhydrophobicity/superoleophilicity, or superhydrophilicity and underwater superoleophobicity are promising candidates for oil/water mixture separation. Nevertheless, a facile yet effective way to design and fabricate porous mesh still remains challenging. In this work, fused deposition modeling (FDM) 3D printing of Fe/polylactic acid (PLA) composites was employed to fabricate superhydrophilic and underwater superoleophobic mesh (S-USM) with hydrogel coatings via the surface polymerization of Fe(II)-mediated redox reaction. In addition, salt of aluminum chloride was incorporated within the hydrogel coating, which was attributed to strengthening the demulsification of oil-in-water emulsions, resulting in efficient separation of oil-in-water mixtures. The S-USM was efficient for a wide range of oil-in-water mixtures, such as dodecane, diesel, vegetable oil, and even crude oil, with a separation efficiency of up to 85%. In this study, the flexible design and fabrication of 3D printing were used for the facile creation of spherical oil skimmers with hydrogel coatings that were capable of removing the floating oil. Most importantly, this work is expected to promote post-treatment processes using 3D printing as a new manufacturing technology and, in this way, a series of devices of specific shape and function will be expanded to satisfy desired requirements and bring great convenience to personal life.

scholarly journals ANALISIS PENGARUH INFILL OVERLAP TERHADAP KARAKTERISTIK PRODUK HASIL 3D PRINTING DENGAN MENGGUNAKAN MATERIAL POLY LACTIC ACID (PLA)

2019 ◽  
Vol 18 (2) ◽  
Author(s):  
Fajri Sri Ardion ◽  
Heru Sukanto ◽  
Joko Triyono
Keyword(s):  
Lactic Acid ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Corn Starch ◽  
Nozzle Diameter ◽  
Bending Test ◽  
Poly Lactic Acid ◽  
Fused Deposition ◽  
Bed Temperature

<div class="WordSection1"><p><em>Rapid prototyping or commonly known as additive manufacturing uses metal and non-metal semi-liquid materials which are compacted layer by layer. Fused deposition modeling (FDM) is one of the methods in the additive manufacturing process that u</em><em>ses</em><em> thermoplastic filaments (PLA and ABS). Poly Lactic Acid (PLA) or poly lactic acid is an organic</em><em> plastic</em><em> or bioplastic made from renewable biomass sources such as corn starch, pea starch and vegetable oils. Important factors affecting the quality of 3D Printing results are nozzle diameter, nozzle temperature, bed temperature, infill patern, </em><em>infill percentage</em><em>, print speed, layer thickness and </em><em>infill overlap</em><em>. </em><em>Infill overlap</em><em> is the percentage of overlapping processes of the filament during the printing process. This research was conducted to determine the effect of </em><em>infill overlap</em><em>on the physical and mechanical properties of 3d printing products. The </em><em>infill overlap</em><em>variations used are 0%, 25%, 50%, and 75% of the nozzle diameter. 50% variation shows better quality when compared to other variations for density test, tensile test, and bending test.</em><em></em></p></div><em><br clear="all" /></em>

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