Room temperature 3D printing of super-soft and solvent-free elastomers

• Published in: Science advances Vol. 6; no. 46
• Main Authors: Xie, Renxuan, Mukherjee, Sanjoy, Levi, Adam E, Reynolds, Veronica G, Wang, Hengbin, Chabinyc, Michael L, Bates, Christopher M
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science (AAAS) 13.11.2020; American Association for the Advancement of Science
• Subjects: MATERIALS SCIENCE; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.abc6900

Super-soft elastomers derived from bottlebrush polymers show promise as advanced materials for biomimetic tissue and device applications, but current processing strategies are restricted to simple molding. Here, we introduce a design concept that enables the three-dimensional (3D) printing of super-soft and solvent-free bottlebrush elastomers at room temperature. The key advance is a class of inks comprising statistical bottlebrush polymers that self-assemble into well-ordered body-centered cubic sphere phases. These soft solids undergo sharp and reversible yielding at 20°C in response to shear with a yield stress that can be tuned by manipulating the length scale of microphase separation. The addition of a soluble photocrosslinker allows complete ultraviolet curing after extrusion to form super-soft elastomers with near-perfect recoverable elasticity well beyond the yield strain. These structure-property design rules create exciting opportunities to tailor the performance of 3D-printed elastomers in ways that are not possible with current materials and processes.