PolyJet 3D Printing of Tissue Mimicking Materials: An Investigation of Characteristic Properties of 3D Printed Synthetic Tissue

AbstractCurrent anatomical 3D printing has been primarily used for education, training, and surgical planning purposes. This is largely due to the models being printed in materials which excel at replicating macro-level organic geometries; however, these materials have the drawback of unrealistic mechanical behavior and system properties compared to biological tissue. The new Digital Anatomy (DA) family of materials from Stratasys utilizes composite printed materials to more closely mimic mechanical behavior of biological tissue, potentially allowing more realistic models for design evaluation. Various experimental DA Solid Organ (SO) configurations were quantitatively evaluated under axial loading for comparison with porcine liver in terms of stiffness. Additionally, Structural Heart - Myocardium (Myo) configurations were quantitatively evaluated under different lubricant conditions for comparison with porcine epicardium and aorta in terms of lubricity. Finally, experimental DA Subcutaneous Tissue configurations were qualitatively evaluated by experts with significant pre-clinical implant experience for cutting, tunneling, and puncture procedures.In general, the experimental SO configurations showed promising compliance results when compared to porcine liver. The stiffness of DA configurations was either within the same range or on the lower bound of porcine tissue stiffness values. The lubricity of DA configurations with surface treatments was comparable with porcine epicardium and aorta. In terms of qualitative cutting, DA did not perform well for any of the configurations; however, tunneling and puncture were rated favorably for some of the experimental configurations. Despite some limitations, DA feels closer to real tissue than other commercially available 3D printed materials. Furthermore, the lower sample-to-sample variability of DA allows for repeatability not provided by biological tissue. The promising results and repeatability indicate that DA materials can be used to configure structures with similar characteristic mechanical properties to porcine liver, epicardium, and subcutaneous tissue, adding new value as not only an educational, training, and surgical tool, but also as a research tool.

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APPLICATION OF 3D PRINTING TECHNOLOGY FOR RAPID TOOLING IN SHEET METAL FORMING

Fundamental and Applied Problems of Engineering and Technology ◽

10.33979/2073-7408-2020-341-3-20-30 ◽

2020 ◽

Vol 3 ◽

pp. 20-30

Author(s):

M.A. SEREZHKIN ◽

D.O. KLIMYUK ◽

A.I. PLOKHIKH

Keyword(s):

3D Printing ◽

Sheet Metal ◽

Sheet Metal Forming ◽

Metal Forming ◽

Rapid Tooling ◽

Printing Technology ◽

3D Printing Technology ◽

3D Printed ◽

Printed Materials ◽

Printing Parameters

The article presents the study of the application of 3D printing technology for rapid tooling in sheet metal forming for custom or small–lot manufacturing. The main issue of the usage of 3D printing technology for die tooling was discovered. It is proposed to use the method of mathematical modelling to investigate how the printing parameters affect the compressive strength of FDM 3D–printed parts. Using expert research methods, the printing parameters most strongly affecting the strength of products were identified for further experiments. A method for testing the strength of 3D–printed materials has been developed and tested.

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Cost-Effectively 3D-Printed Rigid and Versatile Interpenetrating Polymer Networks

Materials ◽

10.3390/ma14164544 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4544

Author(s):

Osman Konuray ◽

Arnau Sola ◽

Jordi Bonada ◽

Agnieszka Tercjak ◽

Albert Fabregat-Sanjuan ◽

...

Keyword(s):

3D Printing ◽

Polymer Networks ◽

Complex Form ◽

Interpenetrating Polymer Networks ◽

Dual Processing ◽

Digital Light Processing ◽

Superior Mechanical Properties ◽

3D Printed ◽

Acrylate Resin ◽

Printed Materials

Versatile acrylate–epoxy hybrid formulations are becoming widespread in photo/thermal dual-processing scenarios, especially in 3D printing applications. Usually, parts are printed in a stereolithography or digital light processing (DLP) 3D printer, after which a thermal treatment would bestow the final material with superior mechanical properties. We report the successful formulation of such a hybrid system, consisting of a commercial 3D printing acrylate resin modified by an epoxy–anhydride mixture. In the final polymeric network, we observed segregation of an epoxy-rich phase as nano-domains, similar to what was observed in a previous work. However, in the current work, we show the effectiveness of a coupling agent added to the formulation to mitigate this segregation for when such phase separation is undesired. The hybrid materials showed significant improvement of Young’s modulus over the neat acrylate. Once the flexible, partially-cured material was printed with a minimal number of layers, it could be molded into a complex form and thermally cured. Temporary shapes were readily programmable on this final material, with easy shape recovery under mild temperatures. Inspired by repairable 3D printed materials described recently, we manufactured a large object by printing its two halves, and then joined them covalently at the thermal cure stage with an apparently seamless union.

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Environment Influence on the Properties of Functional Parts Made of HIPS Material

ECS Transactions ◽

10.1149/10501.0431ecst ◽

2021 ◽

Vol 105 (1) ◽

pp. 431-440

Author(s):

Pavel Šafl ◽

Jana Zimáková ◽

Tomáš Binar

Keyword(s):

Electron Microscope ◽

3D Printing ◽

Tensile Test ◽

Uv Light ◽

Starting Material ◽

Climatic Chamber ◽

3D Printed ◽

Formation Of Cracks ◽

Printed Materials ◽

Degree Of Degradation

The aim of this work is to study the climatic influences on 3D printed materials. This study focuses on the HIPS material, which was chosen as the starting material for further studies. The material in the field of 3D printing is known for its rapid photooxidation, which results in the formation of cracks in the final product. A climatic chamber was used for degradation, in which UV light, heat and increased humidity were applied to the material. The degree of degradation was then checked by tensile test and electron microscope.

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Thermal Conductivity Testing Apparatus for 3D Printed Materials

Volume 2: Heat Transfer Equipment; Heat Transfer in Multiphase Systems; Heat Transfer Under Extreme Conditions; Nanoscale Transport Phenomena; Theory and Fundamental Research in Heat Transfer; Thermophysical Properties; Transport Phenomena in Materials Processing and Manufacturing ◽

10.1115/ht2017-4856 ◽

2017 ◽

Cited By ~ 5

Author(s):

Tiffaney Flaata ◽

Gregory J. Michna ◽

Todd Letcher

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Additive Manufacturing ◽

3D Printing ◽

Polymer Composite ◽

Heat Exchangers ◽

Fused Deposition ◽

3D Printed ◽

Printed Materials ◽

Metal Polymer

Additive manufacturing, the layer-by-layer creation of parts, was initially used for rapid prototyping of new designs. Recently, due to the decrease in the cost and increase in the resolution and strength of additively manufactured parts, additive manufacturing is increasingly being used for production of parts for end-use applications. Fused Deposition Modeling (FDM), a type of 3d printing, is a process of additive manufacturing in which a molten thermoplastic material is extruded to create the desired geometry. Many potential heat transfer applications of 3d printed parts, including the development of additively manufactured heat exchangers, exist. In addition, the availability of metal/polymer composite filaments, first used for applications such as tooling for injection molding applications and to improve wear resistance, could lead to increased performance 3d printed heat exchangers because of the higher thermal conductivity of the material. However, the exploitation of 3d printing for heat transfer applications is hindered by a lack of reliable thermal conductivity data for as-printed materials, which typically include significant void fractions. In this experimental study, an apparatus to measure the effective thermal conductivity of 3d printed composite materials was designed and fabricated. Its ability to accurately measure the thermal conductivity of polymers was validated using a sample of acrylic, whose conductivity is well understood. Finally, the thermal conductivities of various 3d printed polymer, metal/polymer composite, and carbon/polymer composite filaments were measured and are reported in this paper. The materials used are acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), stainless steel/PLA, Brass/PLA, and Bronze/PLA.

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Utility and cost–effectiveness of 3D-printed materials for clinical use

Journal of 3D Printing in Medicine ◽

10.2217/3dp-2019-0015 ◽

2019 ◽

Vol 3 (4) ◽

pp. 209-218 ◽

Cited By ~ 2

Author(s):

Julian Vitali ◽

Matthew Cheng ◽

Michael Wagels

Keyword(s):

Cost Effectiveness ◽

3D Printing ◽

Relevant Literature ◽

Clinical Use ◽

Surgical Guides ◽

Rigorous Testing ◽

Clinical Benefits ◽

3D Printed ◽

Surgical Adjunct ◽

Printed Materials

This review summarizes the utility of 3D-printing as a surgical adjunct, reviewing the cost–effectiveness. The relevant literature was analyzed outlining the utility and/or cost–effectiveness of 3D-printing for clinical use. Compared with existing methods, the evidence suggests an advantage of using 3D-printing as a technology in the treatment of complex clinical cases. However, in high frequency cases, the additional preoperative expenses are not justified. Considerable evidence of its clinical benefits exists for the application of 3D-printed anatomical models and teaching tools. However, the evidence supporting 3D-printing’s use as surgical guides or implantable devices is less clear. Furthermore, caution must exist when using these devices in the clinical setting due to a paucity of rigorous testing, global regulation and long-term data.

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Polyjet 3D printing of tissue-mimicking materials: how well can 3D printed synthetic myocardium replicate mechanical properties of organic myocardium?

10.1101/825794 ◽

2019 ◽

Cited By ~ 3

Author(s):

Leah Severseike ◽

Vania Lee ◽

Taycia Brandon ◽

Chris Bakken ◽

Varun Bhatia

Keyword(s):

Mechanical Properties ◽

Biological Tissue ◽

Mechanical Response ◽

Axial Loading ◽

Stress Concentrations ◽

Friction Forces ◽

Compliance Testing ◽

3D Printed ◽

Printed Materials ◽

Digital Anatomy

AbstractAnatomical 3-D printing has potential for many uses in education, research and development, implant training, and procedure planning. Conventionally, the material properties of 3D printed anatomical models have often been similar only in form and not in mechanical response compared to biological tissue. The new Digital Anatomy material from Stratasys utilizes composite printed materials to more closely mimic the mechanical properties of tissue. Work was done to evaluate Digital Anatomy myocardium under axial loading for comparison with porcine myocardium regarding puncture, compliance, suturing, and cutting performance.In general, the Digital Anatomy myocardium showed promising comparisons to porcine myocardium. For compliance testing, the Digital Anatomy was either within the same range as the porcine myocardium or stiffer. Specifically, for use conditions involving higher stress concentrations or smaller displacements, Digital Anatomy was stiffer. Digital Anatomy did not perform as strongly as porcine myocardium when evaluating suture and cutting properties. The suture tore through the printed material more easily and had higher friction forces both during needle insertion and cutting. Despite these differences, the new Digital Anatomy myocardium material was much closer to the compliance of real tissue than other 3D printed materials. Furthermore, unlike biological tissue, Digital Anatomy provided repeatability of results. For tests such as cyclic compression, the material showed less than two percent variation in results between trials and between parts, resulting in lower variability than tissue. Despite some limitations, the myocardium Digital Anatomy material can be used to configure structures with similar mechanical properties to porcine myocardium in a repeatable manner, making this a valuable research tool.

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Stabilization of Electrospun Nanofiber Mats Used for Filters by 3D Printing

Polymers ◽

10.3390/polym11101618 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1618 ◽

Cited By ~ 11

Author(s):

Kozior ◽

Trabelsi ◽

Mamun ◽

Sabantina ◽

Ehrmann

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Water Pressure ◽

Volume Ratio ◽

Fused Deposition ◽

Rigid Objects ◽

Deposition Modeling ◽

3D Printed ◽

Printed Materials ◽

Nanofiber Mats

Electrospinning is a well-known technology used to create nanofiber mats from diverse polymers and other materials. Due to their large surface-to-volume ratio, such nanofiber mats are often applied as air or water filters. Especially the latter, however, have to be mechanically highly stable, which is challenging for common nanofiber mats. One of the approaches to overcome this problem is gluing them on top of more rigid objects, integrating them in composites, or reinforcing them using other technologies to avoid damage due to the water pressure. Here, we suggest another solution. While direct 3D printing with the fused deposition modeling (FDM) technique on macroscopic textile fabrics has been under examination by several research groups for years, here we report on direct FDM printing on nanofiber mats for the first time. We show that by choosing the proper height of the printing nozzle above the nanofiber mat, printing is possible for raw polyacrylonitrile (PAN) nanofiber mats, as well as for stabilized and even more brittle carbonized material. Under these conditions, the adhesion between both parts of the composite is high enough to prevent the nanofiber mat from being peeled off the 3D printed polymer. Abrasion tests emphasize the significantly increased mechanical properties, while contact angle examinations reveal a hydrophilicity between the original values of the electrospun and the 3D printed materials.

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Mechanical properties comparison of PLA, tough PLA and PC 3D printed materials with infill structure – Influence of infill pattern on tensile mechanical properties

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1208/1/012019 ◽

2021 ◽

Vol 1208 (1) ◽

pp. 012019

Author(s):

Adi Pandzic ◽

Damir Hodzic

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

3D Printing ◽

Material Testing ◽

Fused Deposition Modelling ◽

Fused Deposition ◽

3D Printed ◽

Printed Materials ◽

Product Weight

Abstract One of the advantages provided by fused deposition modelling (FDM) 3D printing technology is the manufacturing of product materials with infill structure, which provides advantages such as reduced production time, product weight and even the final price. In this paper, the tensile mechanical properties, tensile strength and elastic modulus, of PLA, Tough PLA and PC FDM 3D printed materials with the infill structure were analysed and compared. Also, the influence of infill pattern on tensile properties was analysed. Material testing were performed according to ISO 527-2 standard. All results are statistically analysed and results showed that infill pattern have influence on tensile mechanical properties for all three materials.

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Preliminary Study on Polishing SLA 3D-Printed ABS-Like Resins for Surface Roughness and Glossiness Reduction

Micromachines ◽

10.3390/mi11090843 ◽

2020 ◽

Vol 11 (9) ◽

pp. 843

Author(s):

Jungyu Son ◽

Hyunseop Lee

Keyword(s):

Surface Roughness ◽

3D Printing ◽

Acrylonitrile Butadiene Styrene ◽

Machining Processes ◽

Surface Machining ◽

One Step ◽

3D Printed ◽

Printed Materials ◽

The One ◽

Considerable Period

After the development of 3D printing, the post-processing of the 3D-printed materials has been continuously studied, and with the recent expansion of the application of 3D printing, interest in it is increasing. Among various surface-machining processes, chemical mechanical polishing (CMP) is a technology that can effectively provide a fine surface via chemical reactions and mechanical material removal. In this study, two polishing methods were evaluated for the reduction of surface roughness and glossiness of a stereolithography apparatus (SLA) 3D-printed ABS (acrylonitrile butadiene styrene)-like resin. Experiments were conducted on the application of CMP directly to the 3D-printed ABS-like resin (one-step polishing), and on the application of sanding (#2000) and CMP sequentially (two-step polishing). The one-step polishing experiments showed that it took a considerable period of time to remove waviness on the surface of the as-3D printed specimen using CMP. However, in the case of two-step polishing, surface roughness was reduced, and glossiness was increased faster than in the case of one-step polishing via sanding and CMP. Consequently, the experimental results show that the two-step polishing method reduced roughness more efficiently than the one-step polishing method.

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Real-Time Live-Cell Imaging Technology Enables High-Throughput Screening to Verify in Vitro Biocompatibility of 3D Printed Materials

Materials ◽

10.3390/ma12132125 ◽

2019 ◽

Vol 12 (13) ◽

pp. 2125 ◽

Cited By ~ 4

Author(s):

Ina G. Siller ◽

Anton Enders ◽

Tobias Steinwedel ◽

Niklas-Maximilian Epping ◽

Marline Kirsch ◽

...

Keyword(s):

3D Printing ◽

High Throughput Screening ◽

Live Cell Imaging ◽

Cell Imaging ◽

Live Cell ◽

Post Processing ◽

In Vitro Biocompatibility ◽

3D Printed ◽

Printed Materials

With growing advances in three-dimensional (3D) printing technology, the availability and diversity of printing materials has rapidly increased over the last years. 3D printing has quickly become a useful tool for biomedical and various laboratory applications, offering a tremendous potential for efficiently fabricating complex devices in a short period of time. However, there still remains a lack of information regarding the impact of printing materials and post-processing techniques on cell behavior. This study introduces real-time live-cell imaging technology as a fast, user-friendly, and high-throughput screening strategy to verify the in vitro biocompatibility of 3D printed materials. Polyacrylate-based photopolymer material was printed using high-resolution 3D printing techniques, post-processed using three different procedures, and then analyzed with respect to its effects on cell viability, apoptosis, and necrosis of adipogenic mesenchymal stem cells (MSCs). When using ethanol for the post-processing procedure and disinfection, no significant effects on MSCs could be detected. For the analyses a novel image-based live-cell analysis system was compared against a biochemical-based standard plate reader assay and traditional flow cytometry. This comparison illustrates the superiority of using image-based detection of in vitro biocompatibility with respect to analysis time, usability, and scientific outcome.

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