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 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.

scholarly journals Dual-camera system for high-speed imaging in particle image velocimetry

2012 ◽  
Vol 15 (3) ◽  
pp. 193-195 ◽  
Author(s):  
K. Hashimoto ◽  
A. Hori ◽  
T. Hara ◽  
S. Onogi ◽  
H. Mouri
Keyword(s):  
Particle Image Velocimetry ◽  
High Speed ◽  
Particle Image ◽  
High Speed Imaging ◽  
Camera System ◽  
Image Velocimetry

scholarly journals Tomographic particle image velocimetry of desert locust wakes: instantaneous volumes combine to reveal hidden vortex elements and rapid wake deformation

2012 ◽  
Vol 9 (77) ◽  
pp. 3378-3386 ◽  
Author(s):  
Richard J. Bomphrey ◽  
Per Henningsson ◽  
Dirk Michaelis ◽  
David Hollis
Keyword(s):  
Particle Image Velocimetry ◽  
High Speed ◽  
Particle Image ◽  
Aerodynamic Force ◽  
Three Dimensional ◽  
Flow Fields ◽  
Diagnostic Methods ◽  
Tomographic Particle Image Velocimetry ◽  
Image Velocimetry ◽  
Spatio Temporal

Aerodynamic structures generated by animals in flight are unstable and complex. Recent progress in quantitative flow visualization has advanced our understanding of animal aerodynamics, but measurements have hitherto been limited to flow velocities at a plane through the wake. We applied an emergent, high-speed, volumetric fluid imaging technique (tomographic particle image velocimetry) to examine segments of the wake of desert locusts, capturing fully three-dimensional instantaneous flow fields. We used those flow fields to characterize the aerodynamic footprint in unprecedented detail and revealed previously unseen wake elements that would have gone undetected by two-dimensional or stereo-imaging technology. Vortex iso-surface topographies show the spatio-temporal signature of aerodynamic force generation manifest in the wake of locusts, and expose the extent to which animal wakes can deform, potentially leading to unreliable calculations of lift and thrust when using conventional diagnostic methods. We discuss implications for experimental design and analysis as volumetric flow imaging becomes more widespread.

scholarly journals Controlled impact of a disk on a water surface: cavity dynamics

2009 ◽  
Vol 633 ◽  
pp. 381-409 ◽  
Author(s):  
RAYMOND BERGMANN ◽  
DEVARAJ VAN DER MEER ◽  
STEPHAN GEKLE ◽  
ARJAN VAN DER BOS ◽  
DETLEF LOHSE
Keyword(s):  
Particle Image Velocimetry ◽  
Water Surface ◽  
High Speed ◽  
Particle Image ◽  
Boundary Integral ◽  
Infinite Cylinder ◽  
High Speed Imaging ◽  
Image Velocimetry ◽  
Minimal Radius ◽  
Surface Cavity

In this paper we study the transient surface cavity which is created by the controlled impact of a disk of radius h0 on a water surface at Froude numbers below 200. The dynamics of the transient free surface is recorded by high-speed imaging and compared to boundary integral simulations giving excellent agreement. The flow surrounding the cavity is measured with high-speed particle image velocimetry and is found to also agree perfectly with the flow field obtained from the simulations.We present a simple model for the radial dynamics of the cavity based on the collapse of an infinite cylinder. This model accounts for the observed asymmetry of the radial dynamics between the expansion and the contraction phases of the cavity. It reproduces the scaling of the closure depth and total depth of the cavity which are both found to scale roughly as ∝ Fr1/2 with a weakly Froude-number-dependent prefactor. In addition, the model accurately captures the dynamics of the minimal radius of the cavity and the scaling of the volume Vbubble of air entrained by the process, namely, Vbubble/h03∝(1 + 0.26Fr1/2)Fr1/2.

Experimental measurement of large-scale three-dimensional structures in a turbulent boundary layer. Part 2. Long structures

2011 ◽  
Vol 673 ◽  
pp. 218-244 ◽  
Author(s):  
DAVID J. C. DENNIS ◽  
TIMOTHY B. NICKELS
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
High Speed ◽  
Large Scale ◽  
Particle Image ◽  
Three Dimensional ◽  
Velocity Fluctuations ◽  
Taylor’S Hypothesis ◽  
Image Velocimetry ◽  
Streamwise Structures

Three-dimensional (3D) measurements of a turbulent boundary layer have been made using high-speed particle image velocimetry (PIV) coupled with Taylor's hypothesis, with the objective of characterising the very long streamwise structures that have been observed previously. The measurements show the 3D character of both low- and high-speed structures over very long volumes. The statistics of these structures are considered, as is their relationship to the important turbulence quantities. In particular, the length of the structures and their wall-normal extent have been considered and their relationship to the other components of the velocity fluctuations and the instantaneous stress.

A Study of Hydraulic Characteristics of Multi-Square-Hole Orifice Plates

2012 ◽  
Vol 256-259 ◽  
pp. 2470-2473 ◽  
Author(s):  
Zhi Yong Dong ◽  
Yong Gang Yang ◽  
Qi Qi Chen ◽  
Bin Shi
Keyword(s):  
High Speed ◽  
Particle Image ◽  
Three Dimensional ◽  
Hydrodynamic Cavitation ◽  
High Speed Photography ◽  
Hydraulic Characteristics ◽  
System Pressure ◽  
Image Velocimetry ◽  
Working Section ◽  
Square Hole

This paper experimentally investigated hydraulic characteristics in working section of multi-square-hole orifice plates of hydrodynamic cavitation reactor by use of three-dimensional Particle Image Velocimetry (PIV) and High Speed Photography etc. Arrangements of holes in the orifice plates can be divided into diagonal, cross and checkerboard categories. The three-dimensional velocity distribution, pressure and cavitation characteristics for each arrangement of multi-hole orifice plates were measured by PIV system, pressure data acquisition system and high speed camera, and a comparison of hydraulic characteristics of the three categories of arrangements of the multi-hole orifice plates were made.

Analysis of Simultaneous Velocity and Density Distributions for High-Speed CO2 Flow Using Particle Image Velocimetry and Digital Speckle Tomography

2006 ◽  
Vol 326-328 ◽  
pp. 55-58 ◽  
Author(s):  
Han Seo Ko ◽  
Yong Jae Kim ◽  
Oh Chae Kwon ◽  
Koji Okamoto
Keyword(s):  
Particle Image Velocimetry ◽  
High Speed ◽  
Particle Image ◽  
Three Dimensional ◽  
Jet Flow ◽  
Initial Flow ◽  
Density Distributions ◽  
Image Velocimetry ◽  
Digital Speckle ◽  
Tomography Method

Velocity and density distributions of a high-speed and initial CO2 jet flow have been analyzed simultaneously by a developed three-dimensional digital speckle tomography and a particle image velocimetry (PIV). Three high-speed cameras have been used for the tomography and the PIV since a shape of a nozzle for the jet flow is asymmetric and the initial flow is fast and unsteady. The speckle movements between no flow and CO2 jet flow have been obtained by a cross-correlation tracking method so that those distances can be transferred to deflection angles of laser rays for density gradients. The three-dimensional density fields for the high-speed CO2 jet flow have been reconstructed from the deflection angles by the real-time tomography method, and the two-dimensional velocity fields have been calculated by the PIV method simultaneously.

Large Eddy Simulation (LES) and Time-Resolved Particle Image Velocimetry (TR-PIV) in the Wake of a Cavitating Hydrofoil

2005 ◽  
Author(s):  
Martin Wosnik ◽  
Qiao Qin ◽  
Damien T. Kawakami ◽  
Roger E. A. Arndt
Keyword(s):  
Particle Image Velocimetry ◽  
Large Eddy Simulation ◽  
High Speed ◽  
Particle Image ◽  
Three Dimensional ◽  
Pair Type ◽  
Time Resolved ◽  
Eddy Simulation ◽  
Image Velocimetry ◽  
Large Eddy

A Large Eddy Simulation (LES) approach for cavitating flow, based on a virtual single-phase, fully compressible cavitation model which includes the effects of incondensable gas, has been shown to be capable of capturing the complex dynamical features of highly unsteady cavitating flows of two-dimensional hydrofoils. Here the LES results are compared to Time-Resolved Particle Image Velocimetry (TR-PIV) in the wake of a cavitating NACA 0015 hydrofoil, with particular attention to the predicted vortex shedding mechanisms. Despite some difficulty with obtaining vector fields from vortical clouds of vaporous-gaseous bubbles with cross-correlation techniques, the initial results seem promising in that they confirm the existence of a primary vortex pair (type A-B). In addition to TR-PIV, the cavitation cloud shedding was also documented with phase-locked, time-resolved photography and high speed volume-illuminated video, both with simultaneous imaging of side and plan views of the foil. All three experimental techniques confirm the need for fully three-dimensional simulations to properly describe the unsteady, three-dimensional cavitation cloud shedding mechanism.

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.

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