Deformation Compensation During Buoyancy-Enabled Inkjet Printing of Three-Dimensional Soft Tubular Structures

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Kyle Christensen ◽  
Zhengyi Zhang ◽  
Changxue Xu ◽  
Yong Huang
Keyword(s):  
Cross Section ◽  
Inkjet Printing ◽  
Three Dimensional ◽  
Structural Deformation ◽  
Tubular Structures ◽  
Axial Deformation ◽  
Buoyant Force ◽  
Drop On Demand ◽  
Biological Studies

Of various tissues being fabricated using bioprinting, three-dimensional (3D) soft tubular structures have often been the focus since they address the need for printable vasculature throughout a thick tissue and offer potential as perfusable platforms for biological studies. Drop-on-demand inkjetting has been favored as an effective technique to print such 3D soft tubular structures from various hydrogel bioinks. During the buoyancy-enabled inkjet fabrication of hydrogel-based soft tubular structures, they remain submerged in a solution, which crosslinks the printed structures and provides a supporting buoyant force. However, because of the low stiffness of the structures, the structural deformation of printed tubes poses a significant challenge to the process effectiveness and efficiency. To overcome this structural deformation during buoyancy-enabled inkjet printing, predictive compensation approaches are developed to incorporate deformation allowance into the designed shape. Circumferential deformation is addressed by a four-zone approach, which includes base, circular, vertical, and spanning zones for the determination of a designed cross section or compensated printing path. Axial deformation is addressed by the modification of the proposed circumferential compensation based on the distance of a given cross section to the junction of a branching tube. These approaches are found to enable the successful fabrication of straight and branching alginate tubular structures with nearly ideal geometry, providing a good foundation for the wide implementation of the buoyancy-enabled inkjetting technique. While inkjetting is studied herein as a model bioprinting process, the resulting knowledge also applies to other buoyancy-enabled bioprinting techniques.

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.

The Uniform Flexure of an Incomplete Tore

1949 ◽  
Vol 2 (4) ◽  
pp. 469
Author(s):  
W Freiberger ◽  
RCT Smith
Keyword(s):  
General Solution ◽  
Cross Section ◽  
Harmonic Functions ◽  
Rectangular Cross Section ◽  
Three Dimensional ◽  
Elasticity Problems ◽  
Three Dimensional Elasticity ◽  
Derivatives Of ◽  
Special Case

In this paper we discuss the flexure of an incomplete tore in the plane of its circular centre-line. We reduce the problem to the determination of two harmonic functions, subject to boundary conditions on the surface of the tore which involve the first two derivatives of the functions. We point out the relation of this solution to the general solution of three-dimensional elasticity problems. The special case of a narrow rectangular cross-section is solved exactly in Appendix II.

Vibrations of Orthogonally Stiffened Panels

1978 ◽  
Vol 22 (02) ◽  
pp. 100-109 ◽  
Author(s):  
Niels FI. Madsen
Keyword(s):  
Numerical Method ◽  
Cross Section ◽  
Natural Frequencies ◽  
Axial Deformation ◽  
Linear Combinations ◽  
Stiffened Panels ◽  
Natural Frequencies And Modes ◽  
Modes Of Vibration

A general numerical method for the determination of natural frequencies and modes of vibration for orthogonally stiffened panels is presented. The panel is considered as an assembly of prismatic beams and plate strips rigidly connected along their longitudinal edges and transversely stiffened by beams of varying cross section. The modes of vibration are approximated by linear combinations of the analytically calculated modes of vibration for the prismatic panel, resulting from neglecting the transverse stiffening and assuming simple end supports. For the transverse stiffening, the effects of shear deflection, axial deformation, and St. Venant torsion are taken into account. As a practical example, the natural frequencies of a deep girder in a tanker have been calculated.

scholarly journals Processing of two-dimensional velocity fields for reconstructing three-dimensional flow patterns

2021 ◽  
Vol 2127 (1) ◽  
pp. 012031
Author(s):  
S Yu Belov
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Three Dimensional ◽  
Velocity Fields ◽  
Optical Methods ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Optimal Type

Abstract The paper is concerned with the obtaining three-dimensional velocity fields of a gas or liquid flow based on the available cross-sections of this flow. The descriptions of the main optical methods for studying flows are designed to construct a cross-section of the observed process, but it would be much more informative to obtain information in the visualization not in the cross-section of a volume, but in this volume itself. The paper deals with obtaining three-dimensional flow velocity fields using various approximation methods. The method of estimating the most suitable approximating function is also given. The determination of the optimal type of approximation for the reconstruction of the three-dimensional velocity field was tested on an artificially created vortex.

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 Origami tubes with reconfigurable polygonal cross-sections

2016 ◽  
Vol 472 (2185) ◽  
pp. 20150607 ◽  
Author(s):  
E. T. Filipov ◽  
G. H. Paulino ◽  
T. Tachi
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Mechanical Characteristics ◽  
Three Dimensional ◽  
Geometric Design ◽  
Thin Sheets ◽  
Tubular Structures ◽  
Potential Applications ◽  
The Cross ◽  
Mathematical Definitions

Thin sheets can be assembled into origami tubes to create a variety of deployable, reconfigurable and mechanistically unique three-dimensional structures. We introduce and explore origami tubes with polygonal, translational symmetric cross-sections that can reconfigure into numerous geometries. The tubular structures satisfy the mathematical definitions for flat and rigid foldability, meaning that they can fully unfold from a flattened state with deformations occurring only at the fold lines. The tubes do not need to be straight and can be constructed to follow a non-linear curved line when deployed. The cross-section and kinematics of the tubular structures can be reprogrammed by changing the direction of folding at some folds. We discuss the variety of tubular structures that can be conceived and we show limitations that govern the geometric design. We quantify the global stiffness of the origami tubes through eigenvalue and structural analyses and highlight the mechanical characteristics of these systems. The two-scale nature of this work indicates that, from a local viewpoint, the cross-sections of the polygonal tubes are reconfigurable while, from a global viewpoint, deployable tubes of desired shapes are achieved. This class of tubes has potential applications ranging from pipes and micro-robotics to deployable architecture in buildings.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

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