scholarly journals Study of Layer Formation During Droplet-Based Three-Dimensional Printing of Gel Structures

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Kyle Christensen ◽  
Yong Huang
Keyword(s):  
Inkjet Printing ◽  
High Speed ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Layer Formation ◽  
High Speed Imaging ◽  
Three Dimensional Printing ◽  
Drop On Demand ◽  
Image Velocimetry ◽  
Dimensional Printing

Additive manufacturing, also known as three-dimensional (3D) printing, is an approach in which a structure may be fabricated layer by layer. For 3D inkjet printing, droplets are ejected from a nozzle, and each layer is formed droplet by droplet. Inkjet printing has been widely applied for the fabrication of 3D biological gel structures, but the knowledge of the microscale interactions between printed droplets is still largely elusive. This study aims to elucidate the layer formation mechanism in terms of the formation of single lines and layers comprised of adjacent lines during drop-on-demand inkjet printing of alginate using high speed imaging and particle image velocimetry. Inkjet droplets are found to impact, spread, and coalesce within a fluid region at the deposition site, forming coherent printed lines within a layer. The effects of printing conditions on the behavior of droplets during layer formation are discussed and modeled based on gelation dynamics, and recommendations are presented to enable controllable and reliable fabrication of gel structures. The effects of gelation on droplet impact dynamics are found to be negligible during alginate printing, and interfaces are found to form between printed lines within a layer depending on printing conditions, printing path orientation, and gelation dynamics.

Study of Layer Formation During Droplet-Based 3D Printing of Gel Structures

2017 ◽  
Author(s):  
Kyle Christensen ◽  
Yong Huang
Keyword(s):  
3D Printing ◽  
Inkjet Printing ◽  
High Speed ◽  
Particle Image ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Layer Formation ◽  
High Speed Imaging ◽  
Drop On Demand ◽  
Image Velocimetry

Additive manufacturing, also known as three-dimensional (3D) printing, is an approach in which a structure may be fabricated layer by layer. For 3D inkjet printing, droplets are ejected from a nozzle and each layer is formed droplet by droplet. Inkjet printing has been widely applied for the fabrication of 3D biological gel structures, but the knowledge of the microscale interactions between printed droplets is still largely elusive. This study aims to elucidate the alginate layer formation process during drop-on-demand inkjet printing using high speed imaging and particle image velocimetry. Droplets are found to impact, spread, and coalesce within a fluid region at the deposition site, forming coherent printed lines within a layer. Interfaces are found to form between printed lines within a layer depending on printing conditions and printing path orientation. The effects of printing conditions on the behavior of droplets during layer formation are discussed and modeled based on gelation dynamics, and recommendations are presented to enable controllable and reliable fabrication of gel structures.

scholarly journals Laser-induced forward transfer of viscoplastic fluids

2019 ◽  
Vol 880 ◽  
pp. 497-513 ◽  
Author(s):  
Maziyar Jalaal ◽  
Martin Klein Schaarsberg ◽  
Claas-Willem Visser ◽  
Detlef Lohse
Keyword(s):  
High Speed ◽  
Laser Energy ◽  
Three Dimensional ◽  
Liquid Jet ◽  
Control Parameters ◽  
Optimal Conditions ◽  
High Speed Imaging ◽  
Three Dimensional Printing ◽  
Forward Transfer ◽  
Dimensional Printing

Laser-induced forward transfer (LIFT) is a nozzle-free printing technology that can be used for two- and three-dimensional printing. In LIFT, a laser pulse creates an impulse inside a thin film of material that results in the formation of a liquid jet. We experimentally study LIFT of viscoplastic materials by visualizing the process of jetting with high-speed imaging. The shape of the jet depends on the laser energy, focal height, surface tension and material rheology. We theoretically identify the characteristic jetting velocity and how it depends on the control parameters, and define non-dimensional groups to classify the regimes of jetting. Based on the results, we propose the optimal conditions for printing with LIFT technology.

scholarly journals Rebound of self-lubricating compound drops

2020 ◽  
Vol 6 (11) ◽  
pp. eaay3499 ◽  
Author(s):  
Nathan Blanken ◽  
Muhammad Saeed Saleem ◽  
Carlo Antonini ◽  
Marie-Jean Thoraval
Keyword(s):  
Solid Surface ◽  
High Speed ◽  
Water Drop ◽  
Three Dimensional ◽  
Strong Impact ◽  
High Speed Imaging ◽  
Three Dimensional Printing ◽  
Compound Drops ◽  
The Impact ◽  
Dimensional Printing

Drop impact on solid surfaces is encountered in numerous natural and technological processes. Although the impact of single-phase drops has been widely explored, the impact of compound drops has received little attention. Here, we demonstrate a self-lubrication mechanism for water-in-oil compound drops impacting on a solid surface. Unexpectedly, the core water drop rebounds from the surface below a threshold impact velocity, irrespective of the substrate wettability. This is interpreted as the result of lubrication from the oil shell that prevents contact between the water core and the solid surface. We combine side and bottom view high-speed imaging to demonstrate the correlation between the water core rebound and the oil layer stability. A theoretical model is developed to explain the observed effect of compound drop geometry. This work sets the ground for precise complex drop deposition, with a strong impact on two- and three-dimensional printing technologies and liquid separation.

scholarly journals Printed Life

2012 ◽  
Vol 134 (01) ◽  
pp. 44-47 ◽  
Author(s):  
Jean Thilmany
Keyword(s):  
Cell Culture ◽  
Three Dimensional ◽  
Body Part ◽  
Living Cells ◽  
Layer By Layer ◽  
Collagen Scaffolds ◽  
Three Dimensional Printing ◽  
A Cell ◽  
Dimensional Object ◽  
Dimensional Printing

This article discusses the advancement in bioprinting technology that would enable three-dimensional printing of living organs for transplant. Today, artificial or replacement tissue is commonly grown on collagen scaffolds that contain biological starter cells. The goal here is the growing of a biocompatible piece of tissue to repair or replace a patient’s own damaged body part, such as bone, cartilage, blood vessels, or skin. In future, bioprinting technology will allow making living organs for transplant. The method is much the same as additive manufacturing, in which a printer deposits a material, layer by layer, until a three-dimensional object is made. For bioprinting, the material used is likely to be living cells taken directly from the patient’s body and infused into an ink or gel to keep them alive. After printing, the material is incubated in a cell culture that mimics human body conditions until it fuses or becomes otherwise usable for implant.

Three-Dimensional Printing of Stainless Steel Parts

2008 ◽  
Vol 591-593 ◽  
pp. 374-379 ◽  
Author(s):  
Efrain Carreño-Morelli ◽  
Sebastien Martinerie ◽  
Lisa Mucks ◽  
B. Cardis
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Layer By Layer ◽  
Metal Powders ◽  
Selective Deposition ◽  
Three Dimensional Printing ◽  
Dimensional Printing ◽  
Metal Polymer

Stainless steel parts have been manufactured by two different layer by layer additive processes. The first one is a standard three dimensional process, in which metal powders are bound by selective deposition of binder with a printer head. The second one is a novel process, which is based on the selective deposition of a solvent on metal-polymer granule beds. The microstructures of green and sintered parts are characterized by optical and scanning electron microscopy, and the mechanical properties evaluated by hardness and tensile tests. Solvent on granule printing allows to reach mechanical properties similar to those of metal injection moulding parts.

scholarly journals Exploring the Optimal Design for and Experimentation on a Bowl-Based Mechanism for Transplanting Potted Strawberry Seedlings

2021 ◽  
Author(s):  
Yin Daqing ◽  
Yang Yuchao ◽  
Zhou Maile ◽  
Wei Mingxu ◽  
Wang Jinwu
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
High Speed Photography ◽  
Simulation Design ◽  
Three Dimensional Model ◽  
Three Dimensional Printing ◽  
New Device ◽  
Working Principle ◽  
Dimensional Printing ◽  
Actual Trajectory

Abstract To improve the mechanization of strawberry planting integration and the efficiency of fetching and transplanting seedlings, an integrated transplanting mechanism with protruding, fetching and planting is designed. This new device can realize rapid fetching and pushing bowl movements. The working principle of the slewing mechanism is analyzed, a kinematics model of the mechanism is established, and the optimization goal is established. Visual auxiliary analysis software is developed, optimized parameters are established, and the corresponding theoretical trajectory is provided. A three-dimensional model is established and a virtual simulation design analysis is performed to obtain a simulation trajectory. Three-dimensional printing technology is used to manufacture the test prototype, and the actual working trajectory of the test prototype is extracted using high-speed photography technology, which verifies the consistency of the actual trajectory with the theoretical and simulated trajectories. A prototype transplanting experiment is performed, showing that the success rate of seedling extraction is 91.2% and the rate of excellent planting is 82.8%, which meet the requirements for integrated strawberry harvesting, planting and transplanting and verify the correctness and feasibility of the mechanism design.

scholarly journals Topology optimization and 3D printing of multimaterial magnetic actuators and displays

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw1160 ◽  
Author(s):  
Subramanian Sundaram ◽  
Melina Skouras ◽  
David S. Kim ◽  
Louise van den Heuvel ◽  
Wojciech Matusik
Keyword(s):  
Topology Optimization ◽  
High Resolution ◽  
Three Dimensional ◽  
Design Synthesis ◽  
Magnetic Actuators ◽  
Three Dimensional Printing ◽  
Drop On Demand ◽  
Tightly Coupled ◽  
Actuation Systems ◽  
Dimensional Printing

Upcoming actuation systems will be required to perform multiple tightly coupled functions analogous to their natural counterparts; e.g., the ability to control displacements and high-resolution appearance simultaneously is necessary for mimicking the camouflage seen in cuttlefish. Creating integrated actuation systems is challenging owing to the combined complexity of generating high-dimensional designs and developing multifunctional materials and their associated fabrication processes. Here, we present a complete toolkit consisting of multiobjective topology optimization (for design synthesis) and multimaterial drop-on-demand three-dimensional printing for fabricating complex actuators (>106 design dimensions). The actuators consist of soft and rigid polymers and a magnetic nanoparticle/polymer composite that responds to a magnetic field. The topology optimizer assigns materials for individual voxels (volume elements) while simultaneously optimizing for physical deflection and high-resolution appearance. Unifying a topology optimization-based design strategy with a multimaterial fabrication process enables the creation of complex actuators and provides a promising route toward automated, goal-driven fabrication.

scholarly journals Use of additive technologies in the manufacture of central impactors

2021 ◽  
pp. 47-53
Author(s):  
T. Tatarchuk ◽  
Yu. Kravchuk ◽  
V. Pelykh
Keyword(s):  
New Technologies ◽  
Cooling System ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Three Dimensional Printing ◽  
Repair Operation ◽  
Rapid Fabrication ◽  
Cad Cam ◽  
The Cost ◽  
Dimensional Printing

Purpose. Analysis of methods of manufacturing centrifugal blades by 3D printing methods on the example of a modernized cooling system of the AI-450M engine of the Mi-2MSB helicopter. Research methods: calculation method of finite elements, analytical. Results. Studies have shown that the use of layer-by-layer printing technology of the centrifugal wheel of the cooling system provides the following opportunities and improvements: - reduce the percentage of rejection of finished products by 8–9 times; - reduce material consumption by 300–400 %; - increase the speed of production, experiments and testing the manufacture of working elements through the development of new technologies for rapid production (rapid fabrication); - easy printing of previously “impossible” geometry. The analysis of possible types of manufacturing of  working centrifugal wheel and the calculated estimation of thermodynamic parameters in the course of step-by-step drawing of layers of metal is carried out. The problem of a large percentage of defects in the process of classical-mechanical milling of blades was solved by changing the type of production to additive one. Scientific novelty. In today's world, the spread of CAD / CAM / CAE / PLM technologies and the accumulation of a wide library of materials open up a large number of new and more efficient, in terms of economy and quality, methods of manufacturing components and units. Following the example of such giants in the production of aircraft engines as Rolls-Royce Motor, General Electric and Pratt & Whitney, it is clear that the use and development of the latest methods of three-dimensional printing is appropriate. Practical value. The obtained results are important in the further process of production and modernization ofMi-2 helicopter of all modifications with the latest engines, as well as for projects for the development of helicopter construction in Ukraine - МСБ-2 “Hope”, МСБ -6 “Otaman”, МСБ-8 and others. The ability to increase the efficiency of manufacturing the main working elements - blades allows you to reduce the cost of components, their further repair, operation. The most important factor is to increase reliability, as in the manufacture reduces the likelihood of defects, which will not be detected at the stages of intermediate and final control.

scholarly journals Splash-cup plants accelerate raindrops to disperse seeds

2013 ◽  
Vol 10 (79) ◽  
pp. 20120880 ◽  
Author(s):  
Guillermo J. Amador ◽  
Yasukuni Yamada ◽  
Matthew McCurley ◽  
David L. Hu
Keyword(s):  
High Speed ◽  
Cone Angle ◽  
Three Dimensional ◽  
Dispersal Distance ◽  
Optimal Angle ◽  
Three Dimensional Printing ◽  
A Value ◽  
Dispersal Distances ◽  
Drop Impacts ◽  
Dimensional Printing

The conical flowers of splash-cup plants Chrysosplenium and Mazus catch raindrops opportunistically, exploiting the subsequent splash to disperse their seeds. In this combined experimental and theoretical study, we elucidate their mechanism for maximizing dispersal distance. We fabricate conical plant mimics using three-dimensional printing, and use high-speed video to visualize splash profiles and seed travel distance. Drop impacts that strike the cup off-centre achieve the largest dispersal distances of up to 1 m. Such distances are achieved because splash speeds are three to five times faster than incoming drop speeds, and so faster than the traditionally studied splashes occurring upon horizontal surfaces. This anomalous splash speed is because of the superposition of two components of momentum, one associated with a component of the drop's motion parallel to the splash-cup surface, and the other associated with film spreading induced by impact with the splash-cup. Our model incorporating these effects predicts the observed dispersal distance within 6–18% error. According to our experiments, the optimal cone angle for the splash-cup is 40°, a value consistent with the average of five species of splash-cup plants. This optimal angle arises from the competing effects of velocity amplification and projectile launching angle.

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