Lawrence Livermore eliminates external magnets from metal jetting: molten metal becomes actuator
Lawrence Livermore National Laboratory (LLNL) has developed a metal 3D printing system that uses electric current through molten metal to simultaneously generate the ejection force. The technology eliminates permanent magnets and external coils, components traditionally required in magnetohydrodynamic systems.
The novelty is described in international patent application WO2026173624A2, published on August 20, 2026, under the title “Z-Pinch Magnetohydrodynamic Metal Jetting”. The inventors are Jason R. Jeffries, Viktor Sukhotskiy, and Benjamin Thanh Pham, while the owner is Lawrence Livermore National Security, LLC.
- LLNL uses high-intensity electric current to compress and eject droplets of molten metal
- The system eliminates external magnets and coils, simplifying the printhead architecture
- The technology exploits the Z-pinch effect to generate pressure pulses
- Patent published in August 2026 (WO2026173624A2)
The Z-pinch principle applied to jetting
*The LLNL system exploits the interaction between electric current and self-induced magnetic field to radially compress the liquid metal.*
When a very high current flows through the column of liquid metal, it simultaneously generates two phenomena. It creates a magnetic field around the conductor and maintains the current itself.
The interaction between current and magnetic field produces a Lorentz force directed inward. This phenomenon, called Z-pinch, compresses the metal radially.
The compression turns into a pressure pulse capable of expelling a droplet through a small orifice. The molten metal thus becomes both the printing material and the actuator of the process.
Differences from traditional magnetohydrodynamic systems
*Conventional MHD systems require external components to generate the magnetic field necessary for ejection.*
In traditional magnetohydrodynamic metal jetting systems, a permanent magnet or an external coil produces the magnetic field. The electric current passes through the liquid metal and interacts with this external field.
The LLNL system completely eliminates these external elements. The high-intensity current autonomously creates both the magnetic field and the compression force.
This simplification could reduce the construction complexity of the printhead. Fewer components potentially means greater reliability and lower maintenance costs.
The context of Liquid Metal Jetting
*Metal 3D printing via jetting deposits droplets of liquid material instead of selectively melting a powder bed.*
Liquid Metal Jetting uses a principle similar to inkjet printing. The system produces small droplets of liquid metal and deposits them according to the digital model.
The droplets solidify upon contact with the substrate or the previous layer. The component is built progressively layer by layer.
Metals require hundreds or over a thousand degrees to remain liquid. Viscosity, surface tension, and conductivity differ radically from ink. Generating small, regular, and repeatable droplets represents the main difficulty of the process.
Ejection methods in metal jetting
*There are several strategies to create the necessary impulse for the ejection of metal droplets.*
Systems can apply pneumatic pressure on the molten metal reservoir. Others use mechanical systems similar to pistons.
An alternative exploits the electrical and magnetic properties of liquid metals. It is in this category that LLNL's magnetohydrodynamic system falls.
Each approach presents advantages and limitations in terms of ejection frequency, droplet size, range of compatible materials, and construction complexity.
Implications for metal additive manufacturing
*Z-pinch technology could open new possibilities for more compact and versatile jetting systems.*
The elimination of external magnets and coils reduces the footprint of the printhead. This could facilitate multi-nozzle configurations or more compact printheads.
Thermal management could benefit from the reduction of heat-sensitive components in the immediate vicinity of the molten metal. Fewer critical elements means potentially greater tolerance to operating temperatures.
It remains to be verified which metals and alloys are compatible with such high electric currents. The electrical conductivity and magnetic properties of different materials will influence the system's performance.
Development prospects
The U.S. patent application US20260008106A1 was published on January 8, 2026. The filing of patent protection in several jurisdictions suggests a commercial interest in the technology.
LLNL is managed by Lawrence Livermore National Security for the U.S. Department of Energy. The laboratory has a long tradition in research on advanced materials and manufacturing processes.
The technology is still in the development phase. Further tests will be needed to evaluate the performance, reliability, and industrial scalability of the Z-pinch system applied to metal jetting.
article written with the help of artificial intelligence systems
Q&A
How does the Z-pinch system developed by LLNL work?
The system uses a high-intensity electric current passing through molten metal to generate a self-induced magnetic field. This interaction creates a Lorentz force that radially compresses the metal, ejecting droplets through an orifice.
Which components are eliminated compared to traditional MHD systems?
LLNL's technology eliminates the need for permanent magnets and external coils traditionally used to generate the magnetic field. This simplifies the print head architecture by reducing construction complexity.
What is the international patent number for this technology?
The innovation is described in international patent application WO2026173624A2, published on August 20, 2026. The patent title is "Z-Pinch Magnetohydrodynamic Metal Jetting".
Who are the inventors of the Z-pinch technology for metal jetting?
The inventors listed in the patent are Jason R. Jeffries, Viktor Sukhotskiy, and Benjamin Thanh Pham. The patent holder is Lawrence Livermore National Security, LLC.
What advantages does using molten metal as an actuator offer?
By using molten metal as both the printing material and the actuator, external mechanical components are reduced. This can lead to greater system reliability and lower maintenance costs.
