Review Article

Nanofibrils in nature and materials engineering

  • Nature Reviews Materials volume 3, Article number: 18016 (2018)
  • doi:10.1038/natrevmats.2018.16
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Abstract

Nanofibrillar materials, such as cellulose, chitin and silk, are highly ordered architectures, formed through the self-assembly of repetitive building blocks into higher-order structures, which are stabilized by non-covalent interactions. This hierarchical building principle endows many biological materials with remarkable mechanical strength, anisotropy, flexibility and optical properties, such as structural colour. These features make nanofibrillar biopolymers interesting candidates for the development of strong, sustainable and biocompatible materials for environmental, energy, optical and biomedical applications. However, recreating their architecture is challenging from an engineering perspective. Rational design approaches, applying a combination of theoretical and experimental protocols, have enabled the design of biopolymer-based materials through mimicking nature's multiscale assembly approach. In this Review, we summarize hierarchical design strategies of cellulose, silk and chitin, focusing on nanoconfinement, fibrillar orientation and alignment in 2D and 3D structures. These multiscale architectures are discussed in the context of mechanical and optical properties, and different fabrication strategies for the manufacturing of biopolymer nanofibril-based materials are investigated. We highlight the contribution of rational material design strategies to the development of mechanically anisotropic and responsive materials and examine the future of the material-by-design paradigm.

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Acknowledgements

The authors acknowledge the students and colleagues who have worked with us over the years on research projects related to the theme of this Review. The authors also acknowledge the US National Institutes of Health (NIH) (U01EB014976, R01DE016525), the Air Force Office of Scientific Research (FA8650-16C-5020) and the Office of Naval Research (ONR) (N000141612333) for their support of studies related to the topic of this Review. S.L. acknowledges a starting grant given by ShanghaiTech University.

Author information

Affiliations

  1. School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.

    • Shengjie Ling
  2. Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.

    • Shengjie Ling
    •  & Markus J. Buehler
  3. Department of Biomedical Engineering, Tufts University, Medford, MA, USA.

    • Shengjie Ling
    •  & David L. Kaplan
  4. Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.

    • Markus J. Buehler
  5. Center for Computational Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.

    • Markus J. Buehler

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All authors contributed equally to the preparation of this manuscript.

Competing interests

The authors declare no competing interests.

Corresponding authors

Correspondence to David L. Kaplan or Markus J. Buehler.