Development of a Gut-on-a-Chip Microfluidic Device with Three-Dimensionally Printed Human Intestinal Tissue for Studying Human-Microbe Interactions
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Biological and medical sciences↗
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Results for “Three Dimensional Printing”
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Driving macro-scale transformations in three-dimensional-printed biopolymers through controlled induction of molecular anisotropy at the nanoscale
Motivated by the need to harness the properties of renewable and biodegradable polymers for the design and manufacturing of multi-scale structures with complex geometries, we have employed our additive manufacturing platform that leverages molecular self-assembly for the production of metre-scale structures characterized by complex geometries and heterogeneous material composition. As a precursor material, we used chitosan, a chemically modified form of chitin, an abundant and sustainable structural polysaccharide. We demonstrate the ability to control concentration-dependent crystallization as well as the induction of the preferred orientation of the polymer chains through the combination of extrusion-based robotic fabrication and directional toolpathing. Anisotropy is demonstrated and assessed through high-resolution micro-X-ray diffraction in conjunction with finite element simulations. Using this approach, we can leverage controlled and user-defined small-scale propagation of residual stresses to induce large-scale folding of the resulting structures.
36 MATERIALS SCIENCE↗
Effect of process route on powder three-dimensional-printing of metal powders
The purpose of this study is to investigate the effect of two unique processing routes (solvent jetting (SJ) and binder jetting (BJ)), on the green density of printed stainless steel 316L (SS316L) and Nickel (Ni) powders. In the SJ processing route, a solvent is jetted unto the powder/binder mixture to selectively activate the binder, layer by layer. In the BJ processing route, a solution of the binder mixture is jetted onto the powder bed to selectively bind powder particles. The effects of printing parameters such as layer height, roller speed, shaker speed and nozzle temperature on the green density of printed components are investigated and compared for both processing routes. Results show that layer height and nozzle temperature affect the relative density of the printed compact for both processing routes. Slightly higher relative densities were achieved via the SJ route, with the overall highest relative density being 42.7% at 100 µ m layer height and 70% nozzle temperature for the SS316L components and 43.7% at 150 µ m layer height and 90% nozzle temperature for the Ni components, respectively. Results also show an increase in the final sintered relative density with an increase in green (printed) relative density of the solvent jetted SS316L components, with the highest relative density being 87.2%. The paper studies the influence of printing parameters on the green density of printed SS316L and Ni samples in an unprecedented effort to provide a comparative understanding of the process-property relationships in BJ and SJ of SS316L and Ni components to the additive manufacturing research community.
Engineering↗
MADE3D™ (Manufacturing and Additive Design of Electric Machines Enabled by Three-Dimensional Printing) [SWR-20-70]
The MADE3D™ software uses advanced neural networks for realizing novel high torque density electric machine designs with desired functional specifications not limited to but including torque, magnetic loading, and mass. This software allows for a reduction in cost of design by using next-generation computational resources including the cloud while still maintaining high accuracy. The design of the neural networks allows for exploration of large design space and possibilities to find more optimal designs and accommodate new manufacturing technologies like 3D printing.
Sethuraman, Latha↗
Performance of three-dimensional printed nasopharyngeal swabs for COVID-19 testing
At the start of the COVID-19 pandemic, the US faced nationwide shortages of nasopharyngeal swabs due to both overwhelmed supply chains and an increase in demand. To address this shortfall, multiple 3D printed swabs were ultimately produced and sold for COVID-19 testing. In this work, we present a framework for mechanical and functional bench-testing of nasopharyngeal swabs using standard and widely available material testing equipment. Using this framework, we offer a comprehensive, quantitative comparison of the 3D printed swabs to benchmark their performance against traditional flocked swabs. The test protocols were designed to emulate the clinical use of the nasopharyngeal swabs and to evaluate potential failure modes. Overall, the 3D printed swabs performed comparably to, or outperformed, the traditional swabs in all mechanical tests. While traditional swabs outperformed some of the new 3D printed swabs in terms of sample uptake and retention, similar amounts of RNA were recovered from both 3D printed and traditional swabs.
3D printing↗
In situ imaging of three dimensional freeze printing process using rapid x-ray synchrotron radiography
Three dimensional freeze printing (3DFP) combines the advantages of freeze casting and additive manufacturing to fabricate multifunctional aerogels. Freeze casting is a cost-effective, efficient, and versatile method capable of fabricating micro-scale porous structures inside the aerogels for many different applications. The 3DFP provided the capability of fabricating highly customized geometries with controlled microporous structures as well. However, there are still many unexplained phenomena and features because of the complexity of post-processes and indirect observation methods. This study demonstrates the design and construction of the in situ imaging systems, which use the x-ray synchrotron radiography to observe freeze casting and 3DFP processes. With the advantages provided by the in situ x-ray imaging techniques, the ice crystal growth with its unique lamellar structures can be observed during the freeze casting process. Here, the movement of freeze front, material deposition, and growth of ice crystals can also be visualized during the inkjet-based 3DFP process.
3D printing↗
Tailoring of pores in aerogels using 3D printed structures
In one embodiment, a method includes acquiring a three-dimensional printed template created using an additive manufacturing technique, infilling the template with an aerogel precursor solution, allowing formation of a sol-gel, and converting the sol-gel to an aerogel. In another embodiment, a product includes an aerogel having inner channels corresponding to outer walls of a three-dimensional printed template around which the aerogel was formed.
Chandrasekaran, Swetha↗
Apparatus and method for three-dimensional metal printing
An apparatus and device for building an article by additive manufacturing or 3-D printing. The method includes feeding a supply of particulate slurry to and through a nozzle, such as including an integrated pump, to form a plurality of beads and layers of the slurry on a deposition surface, and ultimately forming a desirable article from the layers of deposited material. The liquid phase of the slurry is desirably removed by heat, and the deposited layers can be sintered or otherwise fused as needed.
Klett, James W.↗
Porous ceramics for additive manufacturing, filtration, and membrane applications
In accordance with one aspect of the presently disclosed inventive concepts, a porous ceramic structure includes a three-dimensional printed structure having predefined features, where the three-dimensional structure has a geometric shape. The average length of the features may be at least 10 microns. The three-dimensional structure includes a ceramic material having an open cell structure with a plurality of pores, where the pores form continuous channels through the ceramic material from one side of the ceramic material to an opposite side of the ceramic material.
Campbell, Patrick↗
Ultra-low binder content 3D printed calcium phosphate graphene scaffolds as resorbable, osteoinductive matrices that support bone formation in vivo
Bone regenerative engineering could replace autografts; however, no synthetic material fulfills all design criteria. Nanocarbons incorporated into three-dimensional printed (3DP) matrices can improve properties, but incorporation is constrained to low wt%. Further, unmodified nanocarbons have limited osteogenic potential. Functionalization to calcium phosphate graphene (CaPG) imparts osteoinductivity and osteoconductivity, but loading into matrices remained limited. This work presents ultra-high content (90%), 3DP-CaPG matrices. 3DP-CaPG matrices are highly porous (95%), moderately stiff (3 MPa), and mechanically robust. In vitro, they are cytocompatible and induce osteogenic differentiation of human mesenchymal stem cells (hMSCs), indicated by alkaline phosphatase, mineralization, and COL1α1 expression. In vivo, bone regeneration was studied using a transgenic fluorescent-reporter mouse non-union calvarial defect model. 3DP-CaPG stimulates cellular ingrowth, retains donor cells, and induces osteogenic differentiation. Histology shows TRAP staining around struts, suggesting potential osteoclast activity. Apparent resorption of 3DP-CaPG was observed and presented no toxicity. 3DP-CaPG represents an advancement towards a synthetic bone regeneration matrix.
60 APPLIED LIFE SCIENCES↗
Interfacial Assembly and Jamming of Polyelectrolyte Surfactants: A Simple Route To Print Liquids in Low-Viscosity Solution
Nanoparticle surfactants (NPSs) assembled at the oil-water interface can significantly lower the interfacial tension and be used to structure liquids. However, to realize the three-dimensional printing of one liquid in another, high-viscosity liquids, for example, silicone oil, have been generally used. In this work, we present a simple, low-cost approach to print water in low-viscosity toluene by using a new type of polyelectrolyte surfactant, sodium carboxymethyl cellulose surfactant (CMCS), that forms and assembles at the oil-water interface. The interfacial activity of CMCSs can be enhanced by tuning parameters, such as pH and concentration, and the incorporation of a rigid ligand affords excellent mechanical strength to the resultant assemblies. With CMCS jammed at the interface, liquids can be easily printed or molded to the desired shapes, with biocompatible walls that can be used to encapsulate and adsorb active materials. This study opens a new pathway to generate complex, all-liquid devices with a myriad of potential applications in biology, catalysis, and chemical separation.
36 MATERIALS SCIENCE↗
Design, Manufacturing, and Validation of an Optimized Electric Machine Enabled by 3D Printing
The collaboration between the National Laboratory of the Rockies (NLR) and LaunchPoint Electric Propulsion Solutions, Inc. (LaunchPoint) focuses on manufacturing and additive design of electric machines enabled by DOE’s program for three-dimensional printing (MADE3D) as applied to advanced drivetrains and their impact on turbine capital cost and lifetime energy production. Initial efforts will focus on the rotor structure and rotor core of the drivetrain including the active materials (electrical steel and magnets) and could later expand to the stator. The verification activities will be conducted with an instrumented electric machine and a small dynamometer.
17 WIND ENERGY↗
Packing fraction control during additive manufacturing of powder green bodies
The demand for high performance ceramic and metal components with complex geometry necessitates developments in powder handling and green body shaping. Here, in this study, vibrational powder deposition is adapted to three-dimensional printing with the ability to modulate packing fraction during printing. Boron carbide powder with sub-micron primary particle size is printed over a packing fraction range of 25.0 % to 46.5 % (below the poured density to above the tapped density). Solid metal powders are printed at 67.5 %, which enables novel freestanding, vertical-walled features without binder. These capabilities introduce opportunities for more complex geometries in high-performance materials, e.g. large-scale uniaxial hot-pressing of ceramic ballistic armor components with graded thickness and three-dimensional curved or stepped features (by compensating for displacement differences during compaction). This technology also enables multi-material patterning of additive manufacturing powder beds with reduced feedstock quantity requirements and wastage.
36 MATERIALS SCIENCE↗
3D printed Mg-NiTi interpenetrating-phase composites with high strength, damping capacity, and energy absorption efficiency
It is of significance, but still remains a key challenge, to simultaneously enhance the strength and damping capacities in metals, as these two properties are often mutually exclusive. Here, we provide a multidesign strategy for defeating such a conflict by developing a Mg-NiTi composite with a bicontinuous interpenetrating-phase architecture through infiltration of magnesium melt into three-dimensionally printed Nitinol scaffold. The composite exhibits a unique combination of mechanical properties with improved strengths at ambient to elevated temperatures, remarkable damage tolerance, good damping capacities at differing amplitudes, and exceptional energy absorption efficiency, which is unprecedented for magnesium materials. The shape and strength after deformation can even be largely recovered by heat treatment. This study offers a new perspective for the structural and biomedical applications of magnesium.
36 MATERIALS SCIENCE↗
Novel pore size-controlled, susceptibility matched, 3D-printed MRI phantoms
We report the design concept and fabrication of MRI phantoms, containing blocks of aligned microcapillaires that can be stacked into larger arrays to construct diameter distribution phantoms or fractured, to create a “powder-averaged” emulsion of randomly oriented blocks for vetting or calibrating advanced MRI methods, that is, diffusion tensor imaging, AxCaliber MRI, MAP-MRI, and multiple pulsed field gradient or double diffusion-encoded microstructure imaging methods. The goal was to create a susceptibility-matched microscopically anisotropic but macroscopically isotropic phantom with a ground truth diameter that could be used to vet advanced diffusion methods for diameter determination in fibrous tissues. Two-photon polymerization, a novel three-dimensional printing method is used to fabricate blocks of capillaries. Double diffusion encoding methods were employed and analyzed to estimate the expected MRI diameter. Susceptibility-matched microcapillary blocks or modules that can be assembled into large-scale MRI phantoms have been fabricated and measured using advanced diffusion methods, resulting in microscopic anisotropy and random orientation. This phantom can vet and calibrate various advanced MRI methods and multiple pulsed field gradient or diffusion-encoded microstructure imaging methods. We demonstrated that two double diffusion encoding methods underestimated the ground truth diameter.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
3D Printing of High Viscosity Reinforced Silicone Elastomers
Recent advances in additive manufacturing, specifically direct ink writing (DIW) and ink-jetting, have enabled the production of elastomeric silicone parts with deterministic control over the structure, shape, and mechanical properties. These new technologies offer rapid prototyping advantages and find applications in various fields, including biomedical devices, prosthetics, metamaterials, and soft robotics. Stereolithography (SLA) is a complementary approach with the ability to print with finer features and potentially higher throughput. However, all high-performance silicone elastomers are composites of polysiloxane networks reinforced with particulate filler, and consequently, silicone resins tend to have high viscosities (gel- or paste-like), which complicates or completely inhibits the layer-by-layer recoating process central to most SLA technologies. Herein, the design and build of a digital light projection SLA printer suitable for handling high-viscosity resins is demonstrated. Further, a series of UV-curable silicone resins with thiol-ene crosslinking and reinforced by a combination of fumed silica and MQ resins are also described. The resulting silicone elastomers are shown to have tunable mechanical properties, with 100–350% elongation and ultimate tensile strength from 1 to 2.5 MPa. Three-dimensional printed features of 0.4 mm were achieved, and complexity is demonstrated by octet-truss lattices that display negative stiffness.
36 MATERIALS SCIENCE↗
Direct air capture with amino acid solvent: Operational optimization using a crossflow air‐liquid contactor
Direct air capture (DAC) is a negative emission technology for removing CO2 from the atmosphere to maintain the CO 2 level within a reasonable range so as to address greenhouse effects. In this study, the operational optimization of lab-scale DAC has been investigated using a crossflow air-liquid contactor loaded with a three dimensionally printed Gyroid packing structure and a potassium sarcosinate solvent. The effects of various parameters, including feed air flow rate, liquid solvent flow rate, contactor geometry, and ambient temperature, are examined. The results demonstrate that the Gyroid packing design achieves comparable CO 2 capture performance to conventional packed beds but with a significantly lower pressure drop of up to 77.8%, suggesting its potential as an efficient and cost-effective solution for gas–liquid contactors in DAC. Additionally, the study explores the climate impact on CO 2 capture performance and finds that as the air temperature increases from 35 to 95°F at a fixed relative humidity of 80%, the CO 2 capture rate increased from 23.2% to 46.8% with better stability. The research highlights the importance of optimizing contactor design and operational conditions to improve the CO 2 capture rate and feasibility of DAC systems as a negative emission technology for addressing greenhouse effects.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Towards additive manufacturing of magnetocaloric working materials
The feasibility of three-dimensional printing via the Directed Energy Deposition (DED) technique is demonstrated for the ferromagnetic AlFe 2 B 2 (aka 1-2-2) compound, which shows promise as a working material for room-temperature magnetocaloric devices. Like many intermetallic materials, the 1-2-2 compound is brittle at room temperature; not only is it difficult to synthesize from the melt, it is challenging to form it into useful geometries necessary for effective heat transfer in magnetocaloric devices. Using Laser Engineered Net Shaping (LENS TM ) synthesis from two powder precursors, AlB 2 and Fe, samples of simple (rod) and complex (honeycomb) architectures were successfully synthesized. Furthermore, the phase constitution and distribution, magnetic transition temperature, and saturation magnetization determined for the LENS TM -synthesized rod sample are all similar to those obtained for 1-2-2 materials made by conventional casting. Further, the measured magnetic entropy change, as determined from Maxwell's Relations applied to magnetic data, indicates that the magnetocaloric response of the annealed LENS TM -printed rod samples are comparable to those of the 1-2-2 compounds made by conventional techniques. These results confirm that complex magnetofunctional shapes, which are needed for efficient energy conversion in magnetocaloric devices, can be rapidly fabricated from the AlFe 2 B 2 compound.
36 MATERIALS SCIENCE↗