On-demand three-dimensional freeform fabrication of multi-layered hydrogel scaffold with fluidic channels

2010 ◽  
pp. n/a-n/a ◽  
Author(s):  
Wonhye Lee ◽  
Vivian Lee ◽  
Samuel Polio ◽  
Phillip Keegan ◽  
Jong-Hwan Lee ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hydrogel Scaffold ◽  
Freeform Fabrication ◽  
On Demand

Freeform Vertical and Horizontal Fabrication of Alginate-Based Vascular-Like Tubular Constructs Using Inkjetting

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Changxue Xu ◽  
Zhengyi Zhang ◽  
Kyle Christensen ◽  
Yong Huang ◽  
Jianzhong Fu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Building Blocks ◽  
Important Indicator ◽  
Freeform Fabrication ◽  
Cellular Spheroids ◽  
On Demand ◽  
Extra Effort ◽  
Drop On Demand ◽  
Organ Printing ◽  
Supporting Material

Organ printing, among different tissue engineering innovations, is a freeform fabrication approach for making three-dimensional (3D) tissue and organ constructs using cellular spheroids or bioinks as building blocks. The capability to fabricate vascular-like tubular constructs is an important indicator of the overall feasibility of envisioned organ printing technology. In this study, vascular-like alginate tubes, which mimic typical vascular constructs, are fabricated both vertically and horizontally using drop-on-demand (DOD) inkjetting. Manufacturing-related challenges are different for the vertical and horizontal printing configurations. In general, the vertical printing configuration has instability or collapse/buckling problems and may experience some difficulty in fabricating complex constructs such as Y- or K-shaped constructs if there is no supporting material. The horizontal printing configuration may easily result in a deformed hollow cross section and may require extra effort to mitigate the undesired deformation. It is envisioned that the combination of vertical and horizontal printing provides an efficient and effective way to fabricate complex tubular constructs with both vertical and horizontal branching features.

scholarly journals Accelerated Time and High-Resolution 3D Modeling of the Flow and Dispersion of Noxious Substances over a Gigantic Urban Area—The EMERGENCIES Project

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 640
Author(s):  
Olivier Oldrini ◽  
Patrick Armand ◽  
Christophe Duchenne ◽  
Sylvie Perdriel ◽  
Maxime Nibart
Keyword(s):  
High Resolution ◽  
Urban Area ◽  
3D Modeling ◽  
Three Dimensional ◽  
Hazardous Materials ◽  
Support Tool ◽  
On Demand ◽  
Simulation Domain ◽  
Dimensional Simulation ◽  
Atmospheric Release

Accidental or malicious releases in the atmosphere are more likely to occur in built-up areas, where flow and dispersion are complex. The EMERGENCIES project aims to demonstrate the operational feasibility of three-dimensional simulation as a support tool for emergency teams and first responders. The simulation domain covers a gigantic urban area around Paris, France, and uses high-resolution metric grids. It relies on the PMSS modeling system to model the flow and dispersion over this gigantic domain and on the Code_Saturne model to simulate both the close vicinity and the inside of several buildings of interest. The accelerated time is achieved through the parallel algorithms of the models. Calculations rely on a two-step approach: the flow is computed in advance using meteorological forecasts, and then on-demand release scenarios are performed. Results obtained with actual meteorological mesoscale data and realistic releases occurring both inside and outside of buildings are presented and discussed. They prove the feasibility of operational use by emergency teams in cases of atmospheric release of hazardous materials.

scholarly journals Online Measurement of Deposit Surface in Electron Beam Freeform Fabrication

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4001 ◽  
Author(s):  
Shuhe Chang ◽  
Haoyu Zhang ◽  
Haiying Xu ◽  
Xinghua Sang ◽  
Li Wang ◽  
...  
Keyword(s):  
Electron Beam ◽  
3D Reconstruction ◽  
Three Dimensional ◽  
Thermal Conditions ◽  
Online Measurement ◽  
Three Dimensional Reconstruction ◽  
Continuous Change ◽  
Position Information ◽  
Freeform Fabrication ◽  
Dimensional Reconstruction

In the process of electron beam freeform fabrication (EBF3), due to the continuous change of thermal conditions and variability in wire feeding in the deposition process, geometric deviations are generated in the deposition of each layer. In order to prevent the layer-by-layer accumulation of the deviation, it is necessary to perform online geometry measurement for each deposition layer, based on which the error compensation can be done for the previous deposition layer in the next deposition layer. However, the traditional three-dimensional reconstruction method that employs structured laser cannot meet the requirements of long-term stable operation in the manufacturing process of EBF3. Therefore, this paper proposes a method to measure the deposit surfaces based on the position information of electron beam speckle, in which an electron beam is used to bombard the surface of the deposit to generate the speckle. Based on the structured information of the electron beam in the vacuum chamber, the three-dimensional reconstruction of the surface of the deposited parts is realized without need of additional structured laser sensor. In order to improve the detection accuracy, the detection error is theoretically analyzed and compensated. The absolute error after compensation is smaller than 0.1 mm, and the precision can reach 0.1%, which satisfies the requirements of 3D reconstruction of the deposited parts. An online measurement system is built for the surface of deposited parts in the process of electron beam freeform fabrication, which realizes the online 3D reconstruction of the surface of the deposited layer. In addition, in order to improve the detection stability of the whole system, the image processing algorithm suitable for this scene is designed. The reliability and speed of the algorithm are improved by ROI extraction, threshold segmentation, and expansion corrosion. In addition, the speckle size information can also reflect the thermal conditions of the surface of the deposited parts. Hence, it can be used for online detection of defects such as infusion and voids.

Millimeter-wave on-chip solenoid inductor by on-demand three-dimensional printing of colloidal nanoparticles

2010 ◽  
Vol 97 (24) ◽  
pp. 243109 ◽  
Author(s):  
Niklas C. Schirmer ◽  
Jan Hesselbarth ◽  
Stefan Ströhle ◽  
Brian R. Burg ◽  
Manish K. Tiwari ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Three Dimensional ◽  
Colloidal Nanoparticles ◽  
Three Dimensional Printing ◽  
On Demand ◽  
On Chip ◽  
Dimensional Printing

ATMP-induced three-dimensional conductive polymer hydrogel scaffold for a novel enhanced solid-state electrochemiluminescence biosensor

2019 ◽  
Vol 143 ◽  
pp. 111601 ◽  
Author(s):  
Lian-Hua Xu ◽  
Jun-ji Li ◽  
Hai-Bo Zeng ◽  
Xue-Ji Zhang ◽  
Serge Cosnier ◽  
...  
Keyword(s):  
Solid State ◽  
Conductive Polymer ◽  
Three Dimensional ◽  
Hydrogel Scaffold ◽  
Polymer Hydrogel

scholarly journals Mechanically interlocked 3D multi-material micromachines

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
C. C. J. Alcântara ◽  
F. C. Landers ◽  
S. Kim ◽  
C. De Marco ◽  
D. Ahmed ◽  
...  
Keyword(s):  
Drug Loading ◽  
Three Dimensional ◽  
Dissimilar Materials ◽  
Elastic Behavior ◽  
Small Scale ◽  
Shape Transformation ◽  
On Demand ◽  
Mold Casting ◽  
Metal Organic ◽  
Novel Applications

AbstractMetals and polymers are dissimilar materials in terms of their physicochemical properties, but complementary in terms of functionality. As a result, metal-organic structures can introduce a wealth of novel applications in small-scale robotics. However, current fabrication techniques are unable to process three-dimensional metallic and polymeric components. Here, we show that hybrid microstructures can be interlocked by combining 3D lithography, mold casting, and electrodeposition. Our method can be used to achieve complex multi-material microdevices with unprecedented resolution and topological complexity. We show that metallic components can be combined with structures made of different classes of polymers. Properties of both metals and polymers can be exploited in parallel, resulting in structures with high magnetic responsiveness, elevated drug loading capacity, on-demand shape transformation, and elastic behavior. We showcase the advantages of our approach by demonstrating new microrobotic locomotion modes and controlled agglomeration of swarms.

Modeling of Spatially Controlled Biomolecules in Three-Dimensional Porous Alginate Structures

2010 ◽  
Vol 4 (4) ◽  
Author(s):  
Ibrahim T. Ozbolat ◽  
Bahattin Koc
Keyword(s):  
Computer Aided Design ◽  
Solid Freeform Fabrication ◽  
Imaging Techniques ◽  
Release Kinetics ◽  
Three Dimensional ◽  
Control Release ◽  
Stochastic Approach ◽  
Distribution Characteristics ◽  
Porous Structures ◽  
Freeform Fabrication

This paper presents a computer-aided design (CAD) of 3D porous tissue scaffolds with spatial control of encapsulated biomolecule distributions. A localized control of encapsulated biomolecule distribution over 3D structures is proposed to control release kinetics spatially for tissue engineering and drug release. Imaging techniques are applied to explore distribution of microspheres over porous structures. Using microspheres in this study represents a framework for modeling the distribution characteristics of encapsulated proteins, growth factors, cells, and drugs. A quantification study is then performed to assure microsphere variation over various structures under imaging analysis. The obtained distribution characteristics are mimicked by the developed stochastic modeling study of microsphere distribution over 3D engineered freeform structures. Based on the stochastic approach, 3D porous structures are modeled and designed in CAD. Modeling of microsphere and encapsulating biomaterial distribution in this work helps develop comprehensive modeling of biomolecule release kinetics for further research. A novel multichamber single nozzle solid freeform fabrication technique is utilized to fabricate sample structures. The presented methods are implemented and illustrative examples are presented in this paper.

A Computational Design Framework for a Rapid Solid Freeform Fabrication Process

2000 ◽  
Author(s):  
Deepesh Khandelwal ◽  
T. Kesavadas
Keyword(s):  
Solid Freeform Fabrication ◽  
Optimization Technique ◽  
Three Dimensional ◽  
Computational Design ◽  
Freeform Fabrication ◽  
3D Cad ◽  
Build Time ◽  
Cad Models ◽  
Efficient Machine ◽  
Novel Concept

Abstract Solid Freeform Fabrication (SFF) techniques in recent years have shown tremendous promise in reducing the design time of products. This technique enables designers to get three-dimensional physical prototypes from 3D CAD models. Although SFF has gained popularity, the manufacturing time and cost have limited its use to small and medium sized parts. In this paper we have proposed a novel concept for rapidly building SFF parts by inserting prefabricated inserts into the fabricated part. A computational algorithm was developed for determining ideal placement of inserts/cores in the CAD model of the part being prototyped using a heuristic optimization technique called Simulated Annealing. This approach will also allow the designers to build multi-material prototypes using the Rapid Prototyping (RP) technique. By using cheaper pre-fabricates instead of costly photopolymers, the production cost of the SFFs can be reduced. Additionally it will also reduce build time, resulting in efficient machine utilization.

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