ADVANCED MATERIALS & PROCESSES | JANUARY 2026 48 3D PRINTSHOP RESIN CAN BE BOTH ADDITIVE AND SUBTRACTIVE A hybrid manufacturing system developed by Lawrence Livermore National Laboratory (LLNL) uses a resin that can be used both for additive and subtractive printing. The unique resin enhances traditional 3D printing by introducing dual-wavelength behavior. Under blue light, the resin cures and hardens. Under ultraviolet light, it degrades back into a liquid. The hybrid printing system enables corrective manufacturing, provides improved print resolution, and allows for upcycling and recycling of parts. “Imagine if a company needed a part to fit a certain machine but it’s a prototype and they’re not quite sure what they want,” says LLNL scientist and author Benjamin Alameda. “They could theoretically print with our resin. And if there were defects or something they wanted to change, they don’t have to print a whole new part. They could just shine another wavelength on it and modify the existing part. That’s useful and less wasteful.” As an example, the researchers printed a fluidic device with two separate channels. Using the degradation response of their resin, they were able to connect the channels post-printing. “We made it like this intentionally. But if this was actually a true failure to connect the channels, you would have to redo the entire print,” says LLNL scientist and author Johanna Schwartz. “Now after the fact, it’s a very simple correction. Now it’s usable again.” The team designed the resin to harden and degrade quickly, but not so quickly that it would degrade on its own. They noted that standard coatings can prevent parts from breaking down in the sun’s natural ultra- violet radiation. The scientists are further expanding the capability of this hybrid manufacturing by integrating on-machine metrology and feedback control to automatically and autonomously correct the print errors on-the-fly. llnl.gov. MORPHING STRUCTURES FOR AEROSPACE A unique method of printing composite structures intended for aerospace applications lets the 2D shapes morph into curved 3D structures while in space. Ivan Wu and his advisor, Jeff Baur, from the Grainger College of Engineering, University of Illinois Urbana-Champaign, came up with the idea that could also be used to supply needed structures in remote areas on Earth. “We used a continuous carbon fiber 3D printer to print bundles of fiber, with each fiber about the diameter of a human hair,” Wu says. “As the fiber bundles are drawn by the printer onto a bed, they are compressed and exposed to ultraviolet light, which partially cures them.” The energy efficient liquid resin is molded with the printed carbon fiber design then froze. When the 3D structure is needed, the resin is activated with a low-energy heat stimulus that sets in motion a chemical reaction to cure it into a curved 3D shape. This process, called frontal polymerization, eliminates the need for ovens or autoclaves large enough to cure a full-sized satellite dish. The other piece of the puzzle involved creating mathematical equations to describe the shapes to be printed. Wu sourced equations and wrote the code to program the printer to deposit the fiber bundles onto a bed to create five different 3D configurations: a spiral cylinder, a twist, cone, a saddle and a parabolic dish. aerospace. illinois.edu. The two left panels show low resolution printed shapes (top) and corrected shapes (bottom). In the right two panels hybrid manufacturing is used to correct a gap in a fluidic structure. Courtesy of Howard et al. Left: 3D representation of the intended shape. Middle: fiber bundle pattern determined by analytical solution or numerical methods. Right: manufactured with frontal polymerization of the shapes.
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