MIT researchers’ new technique can 3D print furniture in a few minutes using liquid metal

Liquid metal in new 3D printing technique by MIT

MIT researchers have developed Liquid Metal Printing, a new additive technique that can quickly 3D print furniture and large-scale objects using liquid metal in a matter of minutes. Their study has seen the team 3D print furniture parts like table and chair legs and frames with liquid metal, and the result comes through as sturdy pieces of objects. The process of Liquid Metal Printing starts with a predefined path for the liquid metal to snake through, followed by depositing molten aluminum. The liquid metal quickly hardens and forms the shape of the 3D structure, resulting in a faster way to 3D print robust furniture.

images and video stills courtesy of MIT Self-Assembly Lab

The MIT researchers say Liquid Metal Printing can 3D print ten times faster than a comparable metal additive manufacturing process, and the process of melting the metal may be more efficient than some other methods, given that metal is also more accessible with the abundance of scraps that can be recycled. Skylar Tibbits, the study’s senior author, associate professor in the Department of Architecture, and co-director of the Self-Assembly Lab, says that while the progress in fast 3D printing has been promising, compromises still take place. In the case of Liquid Metal Printing, it is about the resolution of the printed objects and their visual aesthetics.

MIT researchers have developed an additive manufacturing technique that can print rapidly with liquid metal

Sacrificing high resolutions for speed and scale

The Liquid Metal Printing technique exhibits noticeable irregularities with the designs it generates. Rough around the edges, the bumpy surfaces of the results are coupled with some hardened aluminum protruding. The MIT researchers acknowledge this outcome, saying that while the 3D printing technique can produce components that are larger than those typically made with slower additive techniques and at a lower cost, it cannot yet achieve high resolutions. ‘But most of our built world like tables, chairs, and buildings doesn’t need extremely high resolution. Speed and scale, and also repeatability and energy consumption, are all important metrics,’ says Skylar Tibbits.

the liquid metal printing process involves depositing molten aluminum along a predefined path

The MIT researchers also built a machine that can melt the aluminum and hold the liquid metal. Pieces of aluminum are then deposited into an electric furnace, and the machine injects it into the predestined shape or path from a ceramic nozzle. There is a reason the researchers chose ceramic as the nozzle’s body. ‘Molten aluminum will destroy just about everything in its path. We started with stainless steel nozzles and then moved to titanium before we ended up with ceramic. But even ceramic nozzles can clog because the heating is not always entirely uniform in the nozzle tip,’ says Zain Karsan, the study’s lead author and a PhD student at ETH Zurich.

the process can enable the 3D printing of complex geometries, like in a spiral form

Ceramic nozzle for the 3D printer

Combining these developments, furniture parts and objects can be 3D printed using liquid metal in a matter of minutes. Since the molten aluminum cools down after several minutes, the users can immediately use the generated products for their desired purposes. The researchers also found that the larger the amount of aluminum they could melt, the faster the printer could go. Moving forward, the MIT researchers want to improve the machine by finding ways to enable consistent heating in the nozzle and prevent the liquid metal from sticking. A better flow of the molten material along with seeking design alternatives to reduce irregular prints is also being considered.

the feed rate of the liquid metal can be adjusted so the material is deposited as the nozzle moves

As Skylar Tibbits says, ‘If we could make this machine something that people could actually use to melt down recycled aluminum and print parts, that would be a game-changer in metal manufacturing. Right now, it is not reliable enough to do that, but that’s the goal.’ He is joined on the paper by lead author Zain Karsan, who is now a PhD student at ETH Zurich; as well as Kimball Kaiser and Jared Laucks, a research scientist and lab co-director. The research was presented at the Association for Computer-Aided Design in Architecture Conference and recently published in the association’s proceedings.

the MIT researchers also built a machine that can melt the aluminum and hold the liquid metal