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Mimicking biological stress–strain behaviour with synthetic elastomers

Abstract

Despite the versatility of synthetic chemistry, certain combinations of mechanical softness, strength, and toughness can be difficult to achieve in a single material. These combinations are, however, commonplace in biological tissues, and are therefore needed for applications such as medical implants, tissue engineering, soft robotics, and wearable electronics1,2,3,4,5,6,7,8,9. Present materials synthesis strategies are predominantly Edisonian, involving the empirical mixing of assorted monomers, crosslinking schemes, and occluded swelling agents, but this approach yields limited property control2,10,11,12,13,14,15,16. Here we present a general strategy for mimicking the mechanical behaviour of biological materials by precisely encoding their stress–strain curves in solvent-free brush- and comb-like polymer networks (elastomers). The code consists of three independent architectural parameters—network strand length, side-chain length and grafting density. Using prototypical poly(dimethylsiloxane) elastomers, we illustrate how this parametric triplet enables the replication of the strain-stiffening characteristics of jellyfish, lung, and arterial tissues.

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Figure 1: Programming mechanical performance.
Figure 2: Breaking the ‘golden rule’ of synthetic polymers.
Figure 3: Mimicking the mechanical properties of biological tissues with synthetic elastomers and plastomers.

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Acknowledgements

We thank the National Science Foundation for funding (grants DMR 1436201, DMR 1407645 and DMR 1624569). We thank M. Rubinstein for discussions; and E. T. Samulski, G. R. Newkome and K. A. Sheyko for reviewing the paper prior to submission.

Author information

Affiliations

Authors

Contributions

M.V.-V. designed, synthesized and characterized the monomers, polymer melts and elastomers (bottlebrushes, combs and ABA-based). W.F.M.D. performed atomic-force microscopy experiments, rheology measurements and analysis. M.H.E. synthesized PDMS combs and revised the manuscript. A.A.P. synthesized PDMS combs. K.M. provided guidance on the synthesis of bottlebrushes. H.L. and A.V.D. provided theoretical analysis of mechanical properties, developed the theoretical foundation for materials design and ABA networks, and performed computer simulations. S.S.S. was the principal investigator. S.S.S. and A.V.D. were primary writers of the manuscript. All authors discussed the results and provided feedback on the manuscript.

Corresponding authors

Correspondence to Andrey V. Dobrynin or Sergei S. Sheiko.

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The authors declare no competing financial interests.

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Reviewer Information Nature thanks D. Gracias, J. Kornfield and D. Vlassopoulos for their contribution to the peer review of this work.

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Supplementary Information

This file contains Supplementary Information sections S1-S7, which include Supplementary Figures, Tables, Data and additional references. (PDF 3505 kb)

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Vatankhah-Varnosfaderani, M., Daniel, W., Everhart, M. et al. Mimicking biological stress–strain behaviour with synthetic elastomers. Nature 549, 497–501 (2017). https://doi.org/10.1038/nature23673

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