Advanced Photopolymer Materials Engineering for Multiscale Additive Fabrication

Project Overview

The overall project objective was to develop and demonstrate new photocurable materials for additive manufacturing (AM) with improved performance and superior properties. Leveraging the recent innovation known as volumetric AM (VAM) co-invented by UC Berkeley and Lawrence Livermore National Laboratory (LLNL), we developed several new photocurable material systems which are challenging or impossible to implement using layer-by-layer printing methods. Characterizing these curing processes in detail, as well as incorporating computational simulation, enabled a deeper understanding of the polymers' molecular and kinetic behavior during curing. We demonstrated new materials that included tunable thiol-ene thermosets ranging from tough to flexible, silicone elastomers, and the softest biocompatible hydrogels that have been 3D printed to-date. The control we have attained over reaction progress and polymer network formation also illuminates related processes in more traditional layer-wise photopolymer 3D printing.

Mission Impact

LLNL has a thriving core competency in Advanced Materials and Manufacturing, which supports a variety of mission areas. Approximately 30 AM systems at LLNL (both custom-built and commercial) rely on photopolymer resin-based processes. The advancements in science and technology tools due to this project are yielding continued benefits for all these systems in part quality, materials performance, and process reliability. Additionally, by coupling these hardware and materials advancements with computational models (part of LLNL's High Performance Computing and Simulation Core Competency), we have further strengthened the material development and process control within the AM portfolio. This work has also spawned new LDRD research directions, including projects in bioprinting model lung tissue, and developing VAM-printable glass. The project led to the hiring of two postdoctoral staff and one scientific and engineering staff member. Finally, the maturation of the relevant photopolymer science is drawing increased attention from program sponsors, seeking demonstrations of the relevant technologies for fabricating challenging components. We anticipate a continued increase in engagement from these sponsors.

Publications, Presentations, and Patents

Cook, Caitlyn C., Erika J. Fong, Johanna J. Schwartz, Dominique H. Porcincula, Allison C. Kaczmarek, James S. Oakdale, Bryan D. Moran, et al. 2020. "Highly Tunable Thiol-ene Photoresins for Volumetric Additive Manufacturing," Advanced Materials 32 (47): 2003376. https://doi.org/10.1002/adma.202003376.

Huang, Sijia, Steven Adelmund, Pradip S. Pichumani, Johanna J. Schwartz, Yigit Menguc, Maxim Shusteff, and Thomas J. Wallin. 2021. "One-Pot 3D Printing of Robust Multimaterial Devices," ArXiv:2111.10521 [Cond-Mat], November. http://arxiv.org/abs/2111.10521.

Karnes, John J., Todd H. Weisgraber, James S. Oakdale, Magi Mettry, Maxim Shusteff, and Juergen Biener. 2020. "On the Network Topology of Cross-Linked Acrylate Photopolymers: A Molecular Dynamics Case Study," The Journal of Physical Chemistry B 124 (41): 9204-15. https://doi.org/10.1021/acs.jpcb.0c05319.

Rackson, Charles M., Kyle M. Champley, Joseph T. Toombs, Erika J. Fong, Vishal Bansal, Hayden K. Taylor, Maxim Shusteff, and Robert R. McLeod. 2021. "Object-Space Optimization of Tomographic Reconstructions for Additive Manufacturing." Additive Manufacturing 48 (December): 102367. https://doi.org/10.1016/j.addma.2021.102367.

Shusteff, Maxim, et al 2019 "Resin Design for Spatial Control of Photopolymerization in Volumetric Additive Manufacturing (VAM)." In Photopolymerization Fundamentals 2019, Sep 15-18, 2019 Monterey, CA.

Shusteff, Maxim et al 2020 "Material Horizons for Volumetric Additive Manufacturing." In Advances in 3D Printing for Medical Applications, MRS 2020 Virtual Spring Meeting, Nov. 28-29, 2020.

Moran, Bryan, Erika Fong, Caitlyn Cook, and Maxim Shusteff. 2021. "Volumetric Additive Manufacturing System Optics." In Emerging Digital Micromirror Device Based Systems and Applications XIII, edited by Benjamin L. Lee and John Ehmke, 2. Online Only, United States: SPIE. https://doi.org/10.1117/12.2577670.

Shusteff, Maxim et al 2021 "Progress in Photopolymer Resin Development for Volumetric Additive Manufacturing (VAM)." In 2021 Solid Freeform Fabrication Symposium, Aug. 2-4, 2021.

IL-13182: Kelly, B. et al "System and method for computed axial lithography (CAL) for 3D additive manufacturing" U.S. Patent Number 10,647,061, filed 12 May 2017 (granted 12 May, 2020).

IL-13425: Shusteff, M. et al, "Photocurable resins for volumetric additive manufacturing" U.S. Patent Application Number 15/930,822, filed 13 May, 2020.

IL-13536: Shusteff, M. et al "Computed Axial Lithography Optimization System" PCT International Patent Application Number US2021/041306, filed 13 July, 2020.