1995
Patent US5598200A United States
Method and apparatus for producing a discrete droplet of high temperature liquid
Abstract
A method and an apparatus (10) eject on demand a discrete droplet (12) of liquid at a high temperature along a predetermined trajectory (18) by transferring a physical impulse from a low temperature environment to a high temperature environment. The ejector apparatus includes a vessel (26) having an interior (24) that contains a high-temperature liquid (14), such as liquid metal, Al, Zn or Sn. The interior includes an inlet end (30) that receives a thermally insulative impulse transmitting device (22) and a feed supply (34) of the droplet material, and a discharge region (56) having an orifice (16) through which the discrete droplets are ejected. An inert gas is feed through the inlet end and into the vessel to create an overpressure over the liquid so that as the overpressure is increased the droplet size is increased. A heater (70) heats the material contained within the interior. An impulse generator (20) is connected and imparts a physical impulse to the impulse transmitting device to produce an ejection pressure at the orifice to eject a discrete droplet of the high-temperature liquid. The impulse generator including a pulse generator electrically connected to a pulse amplifier that is electrically connected to an acoustic device, such as a loudspeaker.
Inventor David W. Gore
Application US08/378,713 events
1995-01-26
Application filed by Individual
1995-01-26
Priority to US08/378,713
1996-01-22
Priority to EP96904509A
1996-01-22
Priority to PCT/US1996/001132
1997-01-28
Application granted
1997-01-28
Publication of US5598200A
2015-01-26
Anticipated expiration
Status
Expired - Fee Related
https://patents.google.com/patent/US5598200A/en
2014
US20150273577A1
United States
Conductive Liquid Three Dimensional Printer
Abstract
A printer that produces objects from liquid conductive material is disclosed. In one embodiment, the printhead has a chamber for containing liquid conductive material surrounded by an electromagnetic coil. A DC pulse is applied to the electromagnetic coil, resulting in a radially-inward force on the liquid conductive material. The force on the liquid conductive material in the chamber results in a drop being expelled from an orifice. In response to a series of pulses, a series of drops fall onto a platform in a programmed pattern, resulting in the formation of an object.
nventorScott VaderZachary VaderCurrent Assignee Alloy Acquisition Corp LLC
Worldwide applications
2014 US 2017 US
Application US14/228,681 events
2014-03-28
Application filed by Individual
2014-03-28
Priority to US14/228,681
2015-10-01
Publication of US20150273577A1
2017-03-13
Priority to US15/457,586
2017-04-11
Application granted
2017-04-11
Publication of US9616494B2
2022-02-04
Assigned to ALLOY ACQUISITION CORP, LLC
Status
Expired - Fee Related
2034-11-23
Adjusted expiration
https://patents.google.com/patent/US20150273577A1/en
2019
Back in 2013 father and son Scott and Zach Vader developed an alternative additive manufacturing process, Magnetohydrodynamic (MHD) printing. They applied for patent in 2014. Acquired by Xerox in February 2019, Vader Systems’ technology uses wire feedstock in lieu of powder. Gravity feeds the molten metal from a tiny crucible into a nozzle and jets individual molten metal droplets on demand, creating dense metallic parts.
Low-Cost Material
The wire feedstock used in MHD can be as little as one fifth the cost of similar metal in powder form, making the process more cost effective and accessible for a variety of applications and industries. MHD also allows for greater control and geometric freedom in the production of parts by customising drop size, placement and spacing.
Using its drop by drop method, MHD can produce engineered lattice structures without the need for support materials – by overlapping the metal droplets to create an in-built diagonal support system. This helps create more complex structures without the need to remove supports in post production, helping to save time and costs. Geometric complexity can be achieved more easily and more cost effectively than traditional methods like die casting and even PBF, making MHD ideal for lightweighting in industries like automotive and aerospace.
MHD is currently is most suitable for aluminium and zinc alloys, as well as for aluminium alloys that are traditionally considered ‘unweldable’.
Research of Denis Comier - Earl W. Brinkman Professor of Industrial and Systems Engineering at Rochester Institute of Technology
Prof. Comier experimented with using MHD to print aluminium circuit board patterns onto flexible plastic substrates and, he reported that worked quite well. Drop off in conductivity was not there and there is good adhesion to the plastic. The feedstock is two orders of magnitude less expensive than silver nanoparticle inks, which could be a real game-changer in advancing printed electronics from research into industrial applications.
https://www.theengineer.co.uk/content/opinion/how-metal-droplet-jetting-could-make-metal-printing-viable
Molten metal jetting for additive manufacturing
Abstract
In molten metal jetting, where droplets of metal are jetted to 3D print a part, each layer may be traversed each successive layer with a normalizing grinding wheel or other leveling device such as a layer to level each successive layer, and/or the melt reservoir or printing chamber may be filled with an anoxic gas mix to prevent oxidation.
Application US16/427,448 events
2019-05-31 Application filed by Markforged Inc
2019-05-31 Assigned to MARKFORGED, INC.
2019-12-12 Publication of US20190375003A1
2020-03-17 Publication of US10589352B2
2024-12-04 Assigned to CONTINUOUS COMPOSITES INC.
https://patents.google.com/patent/US10589352B2/en
2021
Phd Thesis, 2021
Direct Writing of Printed Electronics through Molten Metal Jetting
Author
Manoj Meda
Advisor
Denis R. Cormier
Advisor/Committee Member
Marcos Esterman
Advisor/Committee Member
Rui Li
Recommended Citation
Meda, Manoj, "Direct Writing of Printed Electronics through Molten Metal Jetting" (2021). Thesis. Rochester Institute of Technology. Accessed from
Magnetohydrodynamic liquid metal droplet jetting of highly conductive electronic traces
Manoj Meda, Paarth Mehta, Chaitanya Mahajan, Bruce Kahn and Denis Cormier∗
Rochester Institute of Technology, Rochester, NY, United States of America
Flex. Print. Electron. 6 (2021) 035002
2025
New Possibilities for Lattice Design and Additive Manufacturing with Molten Metal 3D Printing
Phd Candidate: Paarth Mehta Faculty: Denis Cormier
Rochester Institute of Technology
The burst mode MMJ technique paves the way for lightweight lattice designs that were previously unattainable through other metal 3D printing
methods. As the technology progresses, faster printing with a more comprehensive range of alloys will be possible. Molten metal 3D printing is
becoming essential for fabricating high-performance components across major industries. The breakthroughs from this research will help drive the
overall increased adoption of metal additive manufacturing.
How does molten metal droplet jetting compare to traditional nanoparticle-based conductive inks?
This presentation was given by Denis Cormier from Rochester Institute of Technology at The Future of Electronics RESHAPED USA | Boston 2025 conference and exhibition
2026
Supplier offering Liquid Metal Jetting Parts
RIT AMPrintCenter
Molten Metal Jetting (MMJ) is an emerging metal AM process that offers low cost production
The potential advantages of metal additive manufacturing (AM) envisaged include the elimination of tooling costs, the possibility of on-demand manufacturing close to the point of need, near net shape production that reduces material consumption, and the ability to produce complex geometries that are impossible to make with conventional processes. But much of this potential has not been realized. The majority of production applications for metal AM have been limited to low volume, high-value parts for the aerospace and biomedical industries. Outside of those industries, it is often said that if a part can be CNC machined, then it will be faster and less expensive to CNC machine it than to make it via metal AM. The reasons for this are: Production grade metal AM machines often cost several multiples of the price of one CNC milling machine. Likewise, metal powder can be ten times or more expensive than bar stock used in CNC machining. Per-part print times can run hours to days, versus minutes to hours for CNC machining.
Laser Powder Bed Fusion (L-PBF) is the dominant metal AM process at the present time. l-PBF processes are well understood and are exceptionally well suited for making relatively small parts with intricate detail. The high cost of l-PBF machines and metal powder, coupled with low production speeds and environmental health and safety concerns explain why l-PBF has struggled to gain significant traction beyond the aerospace and biomedical industries. Binder jetting is likewise well suited for production of small metal parts with intricate detail. The equipment costs of binder jetting machines coupled with production-scale debinding and sintering furnaces are similar to those of l-PBF machines. Binder jetting likewise has similar concerns with the cost of metal powders and infrastructure needed to safely handle those powders.
Wire-feed Directed-Energy-Deposition (DED) methods (e.g., Laser Wire DED, Wire Arc AM and Electron Beam Wire AM) typically have lower per-part material costs than powder-based metal AM processes. The relatively high material deposition rates and robot motion stages make them well suited to produce very large parts. The tradeoff for high deposition rate with these processes is coarse feature resolution.
Molten Metal Jetting (MMJ) is an emerging metal AM process that uses on-demand ejection of molten metal droplets from a nozzle to produce metallic parts. There are multiple approaches to generating droplet ejection pressure pulses in MMJ printheads. Pressure may be generated via magnetohydrodynamic (MHD) , electrohydrodynamic (EHD), pneumatic, or vibrating piston jetting methods. Regardless of the droplet actuation method, each of these MMJ variants melts metal in a crucible prior to deposition. This means that any form of feedstock material may be used, including wire, rod, or even grain produced from ingots. For systems that use ingot as the feedstock material, the raw material cost of near net shape MMJ is even lower than that of CNC machined raw material. That represents a very important step towards tilting the scales from CNC machining with large material waste towards use of metal AM.
MMJ has been used to jet alloys of tin, alumimum, and Copper. . Reported droplet diameters range from as small as 50 µm to as large as 700 μm. Current state of the art commercially available systems claim deposition rates up to 199 using a drop size of 700 µm. There is obviously a tradeoff between deposition rate and feature resolution when selecting the diameter of the nozzle that droplets are jetted from. To increase deposition rates without sacrificing feature resolution, an array of individually addressable nozzles can be used.
Ud. 4.4.2026
Pub. 2.4.2026
