Direct Inkjet Deposition of Ceramic Green Bodies: II – Jet Behaviour and Deposit Formation

1998 ◽  
Vol 542 ◽  
Author(s):  
N. Reis ◽  
K. A. M. Seerden ◽  
B. Derby ◽  
J. W. Halloran ◽  
J. R. G. Evans
Keyword(s):  
Pulse Shape ◽  
Three Dimensional ◽  
Jet Formation ◽  
Deposit Formation ◽  
On Demand ◽  
Drop On Demand ◽  
Material Systems ◽  
Hot Melt ◽  
Feature Resolution ◽  
Deposition Conditions

AbstractIn order to successfully build three-dimensional shapes by hot-melt inkjet deposition it is essential to control the building block characteristics, i.e., the deposit geometry, dimensions and fine feature resolution. The deposit formation is mainly dependent on the material systems and their jetting behaviour. It is therefore crucial to understand how the jet formation is affected by the inks 'rheological properties and how to manipulate the jet-head driving parameters to achieve optimum deposition conditions. This paper reports our investigations with a model jet firing station, about the influence of driving parameters of hot-melt drop-on-demand print-heads (e.g., pulse shape and frequency) on the jet and deposit formation characteristics, for both unfilled and powder loaded vehicles.

Links Between Ink Rheology, Drop-on-Demand Jet Formation, and Printability

2009 ◽  
Vol 53 (4) ◽  
pp. 041208 ◽  
Author(s):  
S. D. Hoath ◽  
I. M. Hutchings ◽  
G. D. Martin ◽  
T. R. Tuladhar ◽  
M. R. Mackley ◽  
...  
Keyword(s):  
Jet Formation ◽  
On Demand ◽  
Drop On Demand

scholarly journals Rheological Investigation of Collagen, Fibrinogen, and Thrombin Solutions for Drop-on-Demand 3D Bioprinting

2020 ◽  
Author(s):  
Hemanth Gudapati ◽  
Daniele Parisi ◽  
Ralph H. Colby ◽  
Ibrahim Ozbolat
Keyword(s):  
Bulk Viscosity ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Protein Solutions ◽  
Ionic Surfactant ◽  
3D Bioprinting ◽  
Rheological Measurements ◽  
On Demand ◽  
Drop On Demand ◽  
Air Interface

<p>Collagen, fibrinogen, and thrombin proteins in aqueous buffer solutions are widely used as precursors of natural biopolymers for three-dimensional (3D) bioprinting applications. The proteins are sourced from animals and their quality may vary from batch to batch, inducing differences in the rheological properties of such solutions. In this work, we investigate the rheological response of collagen, fibrinogen, and thrombin protein solutions in bulk and at the solution/air interface. Interfacial rheological measurements show that fibrous collagen, fibrinogen and globular thrombin proteins adsorb and aggregate at the solution/air interface, forming a viscoelastic solid film at the interface. The viscoelastic film corrupts the bulk rheological measurements in rotational rheometers by contributing to an apparent yield stress, which increases the apparent bulk viscosity up to shear rates as high as 1000 s<sup>-1</sup>. The addition of a non-ionic surfactant, such as polysorbate 80 (PS80) in small amounts between 0.001 and 0.1 v/v%, prevents the formation of the interfacial layer, allowing the estimation of true bulk viscosity and viscoelastic properties of the solutions. The estimation of viscosity not only helps in identifying those protein solutions that are potentially printable with drop-on-demand (DOD) inkjet printing but also detects inconsistencies in flow behavior among the batches.</p>

scholarly journals Rheological investigation of collagen, fibrinogen, and thrombin solutions for drop-on-demand 3D bioprinting

Soft Matter ◽  
2020 ◽  
Vol 16 (46) ◽  
pp. 10506-10517 ◽  
Author(s):  
Hemanth Gudapati ◽  
Daniele Parisi ◽  
Ralph H. Colby ◽  
Ibrahim T. Ozbolat
Keyword(s):  
Three Dimensional ◽  
3D Bioprinting ◽  
Aqueous Buffer ◽  
On Demand ◽  
Buffer Solutions ◽  
Drop On Demand

Collagen, fibrinogen, and thrombin proteins in aqueous buffer solutions are widely used as precursors of natural biopolymers in three-dimensional (3D) bioprinting applications.

Alternating Force Based Drop-on-Demand Microdroplet Formation and Three-Dimensional Deposition

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Long Zhao ◽  
Karen Chang Yan ◽  
Rui Yao ◽  
Feng Lin ◽  
Wei Sun
Keyword(s):  
Process Parameters ◽  
Droplet Diameter ◽  
Three Dimensional ◽  
Inertial Force ◽  
Deposition Process ◽  
Droplet Formation ◽  
Solution Viscosity ◽  
Cell Printing ◽  
On Demand ◽  
Drop On Demand

Drop-on-demand (DOD) microdroplet formation and deposition play an important role in additive manufacturing, particularly in printing of three-dimensional (3D) in vitro biological models for pharmacological and pathological studies, for tissue engineering and regenerative medicine applications, and for building of cell-integrated microfluidic devices. In development of a DOD based microdroplet deposition process for 3D cell printing, the droplet formation, controlled on-demand deposition and at the single-cell level, and most importantly, maintaining the viability and functionality of the cells during and after the printing are all remaining to be challenged. This report presents our recent study on developing a novel DOD based microdroplet deposition process for 3D printing by utilization of an alternating viscous and inertial force jetting (AVIFJ) mechanism. The results include an analysis of droplet formation mechanism, the system configuration, and experimental study of the effects of process parameters on microdroplet formation. Sodium alginate solutions are used for microdroplet formation and deposition. Key process parameters include actuation signal waveforms, nozzle dimensional features, and solution viscosity. Sizes of formed microdroplets are examined by measuring the droplet diameter and velocity. Results show that by utilizing a nozzle at a 45 μm diameter, the size of the formed microdroplets is in the range of 52–72 μm in diameter and 0.4–2.0 m/s in jetting speed, respectively. Reproducibility of the system is also examined and the results show that the deviation of the formed microdroplet diameter and the droplet deposition accuracy is within 6% and 6.2 μm range, respectively. Experimental results demonstrate a high controllability and precision for the developed DOD microdroplet deposition system with a potential for precise cell printing.

Rheological Investigation of Collagen, Fibrinogen, and Thrombin Solutions for Drop-on-Demand 3D Bioprinting

2020 ◽  
Author(s):  
Hemanth Gudapati ◽  
Daniele Parisi ◽  
Ralph H. Colby ◽  
Ibrahim Ozbolat
Keyword(s):  
Bulk Viscosity ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Protein Solutions ◽  
Ionic Surfactant ◽  
3D Bioprinting ◽  
Rheological Measurements ◽  
On Demand ◽  
Drop On Demand ◽  
Air Interface

<p>Collagen, fibrinogen, and thrombin proteins in aqueous buffer solutions are widely used as precursors of natural biopolymers for three-dimensional (3D) bioprinting applications. The proteins are sourced from animals and their quality may vary from batch to batch, inducing differences in the rheological properties of such solutions. In this work, we investigate the rheological response of collagen, fibrinogen, and thrombin protein solutions in bulk and at the solution/air interface. Interfacial rheological measurements show that fibrous collagen, fibrinogen and globular thrombin proteins adsorb and aggregate at the solution/air interface, forming a viscoelastic solid film at the interface. The viscoelastic film corrupts the bulk rheological measurements in rotational rheometers by contributing to an apparent yield stress, which increases the apparent bulk viscosity up to shear rates as high as 1000 s<sup>-1</sup>. The addition of a non-ionic surfactant, such as polysorbate 80 (PS80) in small amounts between 0.001 and 0.1 v/v%, prevents the formation of the interfacial layer, allowing the estimation of true bulk viscosity and viscoelastic properties of the solutions. The estimation of viscosity not only helps in identifying those protein solutions that are potentially printable with drop-on-demand (DOD) inkjet printing but also detects inconsistencies in flow behavior among the batches.</p>

scholarly journals A covalently crosslinked bioink for multi-materials drop-on-demand 3D bioprinting of three-dimensional cell cultures

2021 ◽  
Author(s):  
Robert H. Utama ◽  
Vincent T. G. Tan ◽  
Kristel C. Tjandra ◽  
Andrew Sexton ◽  
Duyen H. T. Nguyen ◽  
...  
Keyword(s):  
Cell Culture ◽  
Human Error ◽  
Three Dimensional ◽  
Polymer System ◽  
Ductal Adenocarcinoma ◽  
3D Bioprinting ◽  
Cell Models ◽  
On Demand ◽  
Drop On Demand

AbstractIn vitro three-dimensional (3D) cell models have been accepted to better recapitulate aspects of in vivo organ environment than 2D cell culture. Currently, the production of these complex in vitro 3D cell models with multiple cell types and microenvironments remains challenging and prone to human error. Here we report a versatile bioink comprised of a 4-arm PEG based polymer with distal maleimide derivatives as the main ink component and a bis-thiol species as the activator that crosslinks the polymer to form the hydrogel in less than a second. The rapid gelation makes the polymer system compatible with 3D bioprinting. The ink is combined with a drop-on-demand 3D bioprinting platform consisting of eight independently addressable nozzles and high-throughput printing logic for creating complex 3D cell culture models. The combination of multiple nozzles and fast printing logic enables the rapid preparation of many complex 3D structures comprising multiple hydrogel environments in the one structure in a standard 96-well plate format. The platform compatibility for biological applications was validated using pancreatic ductal adenocarcinoma cancer (PDAC) cells with their phenotypic responses controlled by tuning the hydrogel microenvironment.

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.

Fabrication of 3D Temperature Sensor Using Magnetostrictive Inkjet Printhead

2020 ◽  
Vol 64 (5) ◽  
pp. 50405-1-50405-5
Author(s):  
Young-Woo Park ◽  
Myounggyu Noh
Keyword(s):  
Flexible Electronics ◽  
Inkjet Printing ◽  
Temperature Sensor ◽  
Computer Aided Design ◽  
Low Cost ◽  
Three Dimensional ◽  
Drop On Demand ◽  
Aided Design ◽  
Nanoparticle Ink ◽  
Inkjet Printhead

Abstract Recently, the three-dimensional (3D) printing technique has attracted much attention for creating objects of arbitrary shape and manufacturing. For the first time, in this work, we present the fabrication of an inkjet printed low-cost 3D temperature sensor on a 3D-shaped thermoplastic substrate suitable for packaging, flexible electronics, and other printed applications. The design, fabrication, and testing of a 3D printed temperature sensor are presented. The sensor pattern is designed using a computer-aided design program and fabricated by drop-on-demand inkjet printing using a magnetostrictive inkjet printhead at room temperature. The sensor pattern is printed using commercially available conductive silver nanoparticle ink. A moving speed of 90 mm/min is chosen to print the sensor pattern. The inkjet printed temperature sensor is demonstrated, and it is characterized by good electrical properties, exhibiting good sensitivity and linearity. The results indicate that 3D inkjet printing technology may have great potential for applications in sensor fabrication.

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.

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