Researchers at Lawrence Livermore National Laboratory (LLNL) adapted a replacement class of materials for its groundbreaking volumetric 3D printing method that produces objects nearly instantly & greatly expanding the range of fabric properties achievable with the technique.
The class of materials adapted for volumetric 3-D printing are thiol-ene resins and they are often used with LLNL’s Volumetric Additive Manufacturing (VAM) techniques including Computed Axial Lithography (CAL) which produces objects by projecting beams of 3D patterned light into a vial of resin. As the light cures the liquid resin into a solid at the specified points in the volume & the uncured resin is drained leaving the 3D object behind during a matter of seconds.
Earlier, researchers worked with acrylate-based resins that produced brittle & simply breakable objects using the CAL process. However, the new resin chemistry created through-the careful balancing of three differing types of molecules is more versatile and provides researchers with a versatile design space & wider-range of mechanical performance. With thiol-ene resins, researchers were ready to build tough & strong also as stretchable & versatile objects employing a custom VAM printer at LLNL. The work was recently-published in the journal Advanced Materials & highlighted in Nature.
“These results are a key-step toward our vision of using the VAM paradigm to significantly expand the kinds of materials which can be utilized in light driven 3D printing” said LLNL engineer Maxim Shusteff, the work PI and head of a Laboratory Directed Research & Development project-in advanced photopolymer materials development.
In the paper, researchers also demonstrated the primary example of a way for designing the 3D energy dose delivered into the resin to predict & measure it, successfully printing 3D structures in thiol‐ene resin through tomographic volumetric additive-manufacturing. The demonstration creates a standard reference for controlled 3D fabrication & for comparing resin systems, researchers said.
The team concluded the work represents a “significant advancement“ for volumetric additive- manufacturing as they work toward their goal of manufacturing high performance printed engineering polymers with particular emphasis on using thiol‐ene materials in biological scaffolds. Thiol‐ene materials have shown promise for applications including adhesives, electronics & as biomaterials, researchers said.
“By implementing a nonlinear-threshold response into a broad range-of chemistries, we decide to print with resins like silicones or other materials that impart functionality” said LLNL materials engineer Caitlyn Cook.
By studying how the resin behaves at different light dosages, researchers added they aim to enhance the agreement between computational models & experiments and apply photochemical behaviour to the computed tomography reconstructions that produce the 3D models employ to build objects.