3D printable tough silicone double networks

Nat Commun. 2020 Aug 10;11(1):4000. doi: 10.1038/s41467-020-17816-y.

Abstract

Additive manufacturing permits innovative soft device architectures with micron resolution. The processing requirements, however, restrict the available materials, and joining chemically dissimilar components remains a challenge. Here we report silicone double networks (SilDNs) that participate in orthogonal crosslinking mechanisms-photocurable thiol-ene reactions and condensation reactions-to exercise independent control over both the shape forming process (3D printing) and final mechanical properties. SilDNs simultaneously possess low elastic modulus (E100% < 700kPa) as well as large ultimate strains (dL/L0 up to ~ 400 %), toughnesses (U ~ 1.4 MJ·m-3), and strengths (σ ~ 1 MPa). Importantly, the latent condensation reaction permits cohesive bonding of printed objects to dissimilar substrates with modulus gradients that span more than seven orders of magnitude. We demonstrate soft devices relevant to a broad range of disciplines: models that simulate the geometries and mechanical properties of soft tissue systems and multimaterial assemblies for next generation wearable devices and robotics.

MeSH terms

  • Biomedical Technology
  • Elastic Modulus
  • Materials Testing*
  • Mechanical Phenomena
  • Polymers
  • Printing, Three-Dimensional*
  • Rheology
  • Robotics
  • Silicones / chemistry*
  • Tensile Strength
  • Time Factors
  • Wearable Electronic Devices

Substances

  • Polymers
  • Silicones