Development and Modeling of Melt Electrohydrodynamic-Jet Printing of Phase-Change Inks for High-Resolution Additive Manufacturing

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Chuang Wei ◽  
Jingyan Dong
Keyword(s):  
Surface Tension ◽  
Additive Manufacturing ◽  
High Resolution ◽  
Phase Change ◽  
Electrostatic Force ◽  
Droplet Diameter ◽  
Scaling Law ◽  
Process Conditions ◽  
Drop On Demand ◽  
Jet Printing

This paper presents the development and modeling a high-resolution electrohydrodynamic-jet (EHD-jet) printing process using phase-change ink (i.e., wax), which is capable of producing sub-10 μm footprints (sub-10 fL in volume) for super-resolution additive manufacturing. In this study, we successfully apply EHD-jet printing for phase-change ink (wax), which is widely used as modeling and supporting material for additive manufacturing, to achieve micron-scale features. The resolution for single droplet on substrate is around 5 μm with the thickness in the range of 1–2 μm, which provides great potential in both high-resolution 3D printing and 2D drop-on-demand microfabrication. The droplet formation in EHD printing is modeled by finite element analysis (FEA). Two important forces in EHD printing, electrostatic force and surface tension force, are modeled separately by FEA. The droplet size is obtained by balancing the electrostatic force and surface tension of the pending droplets around meniscus apex. Furthermore, to predict the droplet dimension at different process conditions, a dimensionless scaling law is identified to describe the relationship between dimensionless droplet diameter and modified nondimensional electrical bond number. Finally, the droplets in-flight velocity and impact characteristics (e.g., Reynolds number and Weber number) are modeled using the results from FEA analysis.

scholarly journals Sensitivity of Thermal Predictions to Uncertain Surface Tension Data in Laser Additive Manufacturing

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
J. Coleman ◽  
A. Plotkowski ◽  
B. Stump ◽  
N. Raghavan ◽  
A. S. Sabau ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Tension ◽  
Fluid Flow ◽  
Additive Manufacturing ◽  
Current Model ◽  
Surface Tension Gradient ◽  
Process Conditions ◽  
Conductive Heat ◽  
Melt Pool ◽  
Super Alloy

Abstract To understand the process-microstructure relationships in additive manufacturing (AM), it is necessary to predict the solidification characteristics in the melt pool. This study investigates the influence of Marangoni driven fluid flow on the predicted melt pool geometry and solidification conditions using a continuum finite volume model. A calibrated laser absorptivity was determined by comparing the model predictions (neglecting fluid flow) against melt pool dimensions obtained from single laser melt experiments on a nickel super alloy 625 (IN625) plate. Using this calibrated efficiency, predicted melt pool geometries agree well with experiments across a range of process conditions. When fluid mechanics is considered, a surface tension gradient recommended for IN625 tends to overpredict the influence of convective heat transfer, but the use of an intermediate value reported from experimental measurements of a similar nickel super alloy produces excellent experimental agreement. Despite its significant effect on the melt pool geometry predictions, fluid flow was found to have a small effect on the predicted solidification conditions compared to processing conditions. This result suggests that under certain circumstances, a model only considering conductive heat transfer is sufficient for approximating process-microstructure relationships in laser AM. Extending the model to multiple laser passes further showed that fluid flow also has a small effect on the solidification conditions compared to the transient variations in the process. Limitations of the current model and areas of improvement, including uncertainties associated with the phenomenological model inputs are discussed.

Nano-Sized Ceramic Inks for Drop-on-Demand Ink-Jet Printing in Quadrichromy

2008 ◽  
Vol 8 (4) ◽  
pp. 1979-1988 ◽  
Author(s):  
Davide Gardini ◽  
Michele Dondi ◽  
Anna Luisa Costa ◽  
Francesco Matteucci ◽  
Magda Blosi ◽  
...  
Keyword(s):  
Surface Tension ◽  
Particle Size ◽  
Ceramic Tiles ◽  
Nozzle Clogging ◽  
Ink Jet Printing ◽  
Drop On Demand ◽  
Wide Range ◽  
Ink Jet ◽  
Long Time ◽  
Jet Printing

Nano-sized ceramic inks suitable for ink-jet printing have been developed for the four-colours CMYK (cyan, magenta, yellow, black) process. Nano-inks of different pigment composition (Co1–xO, Au0, Ti1–x–ySbxCryO2, CoFe2O4) have been prepared with various solid loadings and their chemico-physical properties (particle size, viscosity, surface tension, ζ-potential) were tailored for the ink-jet application. The pigment particle size is in the 20–80 nm range. All these nano-suspensions are stable for long time (i.e., several months) due to either electrostatic (high ζ-potential values) or steric stabilization mechanisms. Both nanometric size and high stability avoid problems of nozzle clogging from particles agglomeration and settling. Nano-inks have a Newtonian behaviour with relatively low viscosities at room temperature. More concentrated inks fulfil the viscosity requirement of ink-jet applications (i.e., <35 mPa˙s) for printing temperatures in between 30 and 70 °C. Surface tension constraints for ink-jet printing are fulfilled by nano-inks, being in the 35–45 mN˙m–1 range. The nano-sized inks investigated behave satisfactorily in preliminary printing tests on several unfired industrial ceramic tiles, developing saturated colours in a wide range of firing temperatures (1000–1200 °C).

Deposition of Molten Eutectic Solder using Jet Printing Techniques

1995 ◽  
Vol 390 ◽  
Author(s):  
Michael D. Snyder ◽  
Ronald Lasky
Keyword(s):  
Surface Tension ◽  
Circuit Boards ◽  
Eutectic Solder ◽  
On Demand ◽  
Drop On Demand ◽  
Single Feature ◽  
Ink Jet ◽  
Jet Printing ◽  
Printing Techniques ◽  
Large Spherical

ABSTRACTThis paper discusses the use of Ink Jet printing techniques to dispense small (50 to 75 micrometer diameter) particles of molten eutectic solder individually at programmable dispense rates from drop on demand to several thousand per second. Alternative jet dispensing techniques are discussed. The technology could allow the selective application of programmable amounts of solder on precision circuit boards and wafer substrates, while avoiding the high cost and flexibility limits associated with hard tooling. Large solder features can be constructed by dispensing individual droplets and relying on surface tension to draw them together to form a large single feature. Alternatively, columnar features can be created by successively dispensing solder droplets at the same site, allowing time between successive droplets to avoid forming a single large spherical feature.Several potential application areas in industry are discussed along with some of the issues associated with the projected performance of the method in the accuracy and speed domains.

Airflow Assisted Electrohydrodynamic Jet Printing: An Advanced Micro-Additive Manufacturing Technique

2015 ◽  
Author(s):  
Lai Yu Leo Tse ◽  
Kira Barton
Keyword(s):  
Additive Manufacturing ◽  
High Resolution ◽  
Electric Fields ◽  
Large Range ◽  
Diverse Range ◽  
Electrohydrodynamic Jet Printing ◽  
Conductive Substrate ◽  
Jet Printing ◽  
Working Principle ◽  
Manufacturing Technologies

Electrohydrodynamic jet (e-jet) printing is a growing technology for high resolution (<20μm) printing. It enjoys the advantages of other additive manufacturing technologies and is compatible with a large range of materials. E-jet applications include electronic fabrication, high-resolution prototyping, and bio-medical devices. Despite the diverse range of applications, e-jet printing dynamics are sensitive to varying standoff heights and changing electric fields. As such, conventional e-jet printing generally consists of a conductive nozzle printing onto a flat, conductive substrate. To address this limitation, this paper presents an airflow assisted e-jet printhead that is shown to greatly reduce the substrate effects while providing good printing resolution (<15μm). The working principle and design challenges are provided. Experimental demonstrations validate the performance capabilities of the modified e-jet printhead.

scholarly journals Designs and applications of electrohydrodynamic 3D printing

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Dajing Gao ◽  
Jack Zhou
Keyword(s):  
Additive Manufacturing ◽  
High Resolution ◽  
3D Printing ◽  
Inkjet Printing ◽  
Current Trend ◽  
Significant Progress ◽  
Research Directions ◽  
Manufacturing Method ◽  
Jet Printing ◽  
Printing Machine

This paper mainly reviews the designs of electrohydrodynamic (EHD) inkjet printing machine and related applications. The review introduces the features of EHD printing and its possible research directions. Significant progress has been identified in research and development of EHD high-resolution printing as a direct additive manufacturing method, and more effort will be driven to this direction soon. An introduction is given about current trend of additive manufacturing and advantages of EHD inkjet printing. Designs of EHD printing platform and applications of different technologies are discussed. Currently, EHD jet printing is in its infancy stage with several inherent problems to be overcome, such as low yielding rate and limitation of stand-off height. Some potential modifications are proposed to improve printing performance. EHD high-resolution printing has already been applied to precision components for electronics and biotechnology applications. This paper gives a review about the latest research regarding EHD used for high-resolution inkjet printing. A starting base is given to help researchers and students to get a quick overview on the recent development of EHD printing technology.

High-resolution additive direct writing of metal micro/nanostructures by electrohydrodynamic jet printing

2021 ◽  
Vol 543 ◽  
pp. 148800
Author(s):  
Wuhao Zou ◽  
Haibo Yu ◽  
Peilin Zhou ◽  
Ya Zhong ◽  
Yuechao Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Direct Writing ◽  
Electrohydrodynamic Jet Printing ◽  
Jet Printing

scholarly journals Eco-Friendly Lead-Free Solder Paste Printing via Laser-Induced Forward Transfer for the Assembly of Ultra-Fine Pitch Electronic Components

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3353
Author(s):  
Marina Makrygianni ◽  
Filimon Zacharatos ◽  
Kostas Andritsos ◽  
Ioannis Theodorakos ◽  
Dimitris Reppas ◽  
...  
Keyword(s):  
High Resolution ◽  
Form Factors ◽  
Circuit Board ◽  
Lead Free ◽  
Process Conditions ◽  
Solder Paste ◽  
Electronic Components ◽  
Successful Operation ◽  
Fine Pitch ◽  
Forward Transfer

Current challenges in printed circuit board (PCB) assembly require high-resolution deposition of ultra-fine pitch components (<0.3 mm and <60 μm respectively), high throughput and compatibility with flexible substrates, which are poorly met by the conventional deposition techniques (e.g., stencil printing). Laser-Induced Forward Transfer (LIFT) constitutes an excellent alternative for assembly of electronic components: it is fully compatible with lead-free soldering materials and offers high-resolution printing of solder paste bumps (<60 μm) and throughput (up to 10,000 pads/s). In this work, the laser-process conditions which allow control over the transfer of solder paste bumps and arrays, with form factors in line with the features of fine pitch PCBs, are investigated. The study of solder paste as a function of donor/receiver gap confirmed that controllable printing of bumps containing many microparticles is feasible for a gap < 100 μm from a donor layer thickness set at 100 and 150 μm. The transfer of solder bumps with resolution < 100 μm and solder micropatterns on different substrates, including PCB and silver pads, have been achieved. Finally, the successful operation of a LED interconnected to a pin connector bonded to a laser-printed solder micro-pattern was demonstrated.

Chip-scale alignment of long DNA nanofibers on a patterned self-assembled monolayer

Lab on a Chip ◽  
2017 ◽  
Vol 17 (19) ◽  
pp. 3234-3239 ◽  
Author(s):  
J. Xia ◽  
M. Su
Keyword(s):  
Surface Tension ◽  
Genomic Dna ◽  
Electrostatic Force ◽  
Self Assembled Monolayer ◽  
Self Assembled ◽  
Micro Patterns

Centimeter-long genomic DNA nanofibers produced by the interplay between surface tension and electrostatic force of micro-patterns.

Electrohydrodynamic Printing for Advanced Micro/Nanomanufacturing: Current Progresses, Opportunities, and Challenges

2018 ◽  
Vol 6 (4) ◽  
Author(s):  
Yiwei Han ◽  
Jingyan Dong
Keyword(s):  
Additive Manufacturing ◽  
High Resolution ◽  
Potential Application ◽  
Printed Electronics ◽  
Photonic Devices ◽  
Critical Factors ◽  
Biomedical Sensors ◽  
Electrohydrodynamic Printing ◽  
Nanoscale Fabrication ◽  
Printing Processes

The paper provides an overview of high-resolution electrohydrodynamic (EHD) printing processes for general applications in high-precision micro/nanoscale fabrication and manufacturing. Compared with other printing approaches, EHD printing offers many unique advantages and opportunities in the printing resolution, tunable printing modes, and wide material applicability, which has been successfully applied in numerous applications that include additive manufacturing, printed electronics, biomedical sensors and devices, and optical and photonic devices. In this review, the EHDs-based printing mechanism and the resulting printing modes are described, from which various EHD printing processes were developed. The material applicability and ink printability are discussed to establish the critical factors of the printable inks in EHD printing. A number of EHD printing processes and printing systems that are suitable for micro/nanomanufacturing applications are described in this paper. The recent progresses, opportunities, and challenges of EHD printing are reviewed for a range of potential application areas.

scholarly journals Spray adjuvant characteristics affecting agricultural spraying drift

2015 ◽  
Vol 35 (1) ◽  
pp. 109-116 ◽  
Author(s):  
RONE B. DE OLIVEIRA ◽  
ULISSES R. ANTUNIASSI ◽  
MARCO A. GANDOLFO
Keyword(s):  
Surface Tension ◽  
Wind Tunnel ◽  
Aqueous Solutions ◽  
Formation Process ◽  
Droplet Diameter ◽  
Brilliant Blue ◽  
Medium Size ◽  
Blue Dye ◽  
Methods Of Evaluation ◽  
Spray Adjuvants

This study defined the main adjuvant characteristics that may influence or help to understand drift formation process in the agricultural spraying. It was evaluated 33 aqueous solutions from combinations of various adjuvants and concentrations. Then, drifting was quantified by means of wind tunnel; and variables such as percentage of droplets smaller than 50 μm (V50), 100 μm (V100), diameter of mean volume (DMV), droplet diameter composing 10% of the sprayed volume (DV0.1), viscosity, density and surface tension. Assays were performed in triplicate, using Teejet XR8003 flat fan nozzles at 200 kPa (medium size droplets). Spray solutions were stained with Brilliant Blue Dye at 0.6% (m/ v). DMV, V100, viscosity cause most influence on drift hazardous. Adjuvant characteristics and respective methods of evaluation have applicability in drift risk by agricultural spray adjuvants.

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