TECHNOLOGY/BUSINESS OPPORTUNITY Improved Liquid Droplet Ejection from Gas-Pressurized Printhead

Opportunity: Lawrence Livermore National Laboratory (LLNL), operated by the Lawrence Livermore National Security (LLNS), LLC under contract no. DE-AC52-07NA27344 (Contract 44) with the U.S. Department of Energy (DOE), is offering the opportunity to enter into a collaboration to further develop its drop-on-demand additive manufacturing method of droplet ejection using sequenced pressure pulses.Background: For metal additive manufacturing, Drop-on-Demand Liquid Metal Jetting (DOD-LMJ) is a less expensive alternative to Laser Powder Bed Fusion (L-PBF). In DOD-LMJ, a momentum pulse pushes out discrete droplets of molten metal through the nozzle in a controlled stream that then rapidly cools and solidifies upon impact; metal structures of arbitrary shape can then be fabricated. The challenge of DOD-LMJ is the method should produce a constant jet of uniform, single droplets of the molten material at a much faster flow rate than conventional LMJ.Description: LLNL’s approach to meet this

challenge is to use a pneumatic DOD-LMJ method wherein the nozzle is filled with a molten pure metal or metal alloy. There are two reservoirs in LLNL’s invention that are in direct contact with each other: the liquid metal reservoir that is constantly heated so the metal remains molten and an inert gas reservoir, which is connected to an inert gas pressure source. An electronically controlled valve controls the rate of gas flow in and out of the gas reservoir. By rapidly opening and closing this valve, a sequence of rapid inflows of inert gas into a gas reservoir displaces liquid volume and causes the dense liquid within the nozzle to pressurize and molten material to protrude from the nozzle. The pressure valve is then quickly shut off, while a second valve opens to release the pressurized gas to the atmosphere. This allows any ejected liquid material to naturally retract back into the nozzle, while a disconnected droplet is allowed to escape from the nozzle, traveling by its own momentum towards the substrate. Advantages/Benefits:Value Proposition: Improved control over droplet ejection in pneumatic Drop-on-Demand (DOD) 3D printersFaster pressure response provides better timing control of droplet formationDroplets are formed closer to the nozzle, which reduces meniscus oscillations and allows for a higher max ejection frequencyPotential Applications: Drop-on-Demand Additive ManufacturingLiquid metal printingMicrocastingDevelopment Status: Current stage of technology development: TRL 3LLNL has filed for patent protection on this invention.LLNL is seeking industry partners with a demonstrated ability to bring such inventions to the market. Moving critical technology beyond the Laboratory to the commercial world helps our licensees gain a competitive edge in the marketplace. All licensing activities are conducted under policies relating to the strict nondisclosure of company proprietary information. Please visit the IPO website at https://ipo.llnl.gov/resources for more information on working with LLNL and the industrial partnering and technology transfer process.Note: THIS IS NOT A PROCUREMENT. Companies interested in commercializing LLNL's liquid droplet ejection technology should provide an electronic OR written statement of interest, which includes the following:Company Name and address.The name, address, and telephone number of a point of contact.A description of corporate expertise and/or facilities relevant to commercializing this technology.Please provide a complete electronic OR written statement to ensure consideration of your interest in LLNL's liquid droplet ejection technology.The subject heading in an email response should include the Notice ID and/or the title of LLNL’s Technology/Business Opportunity and directed to the Primary and Secondary Point of Contacts listed below.Written responses should be directed to:Lawrence Livermore National LaboratoryInnovation and Partnerships OfficeP.O. Box 808, L-779Livermore, CA 94551-0808Attention: IL-13866