ABSTRACT High-performance actuating materials are necessary for advances in robotics, prosthetics and smart clothing. Here we report a class of fibre actuators that combine solution-phase

block copolymer self-assembly and strain-programmed crystallization. The actuators consist of highly aligned nanoscale structures with alternating crystalline and amorphous domains,

resembling the ordered and striated pattern of mammalian skeletal muscle. The reported nanostructured block copolymer muscles excel in several aspects compared with current actuators,

including efficiency (75.5%), actuation strain (80%) and mechanical properties (for example, strain-at-break of up to 900% and toughness of up to 121.2 MJ m−3). The fibres exhibit on/off

and recyclable actuators using block copolymers. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution ACCESS OPTIONS Access

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customer support SIMILAR CONTENT BEING VIEWED BY OTHERS BIOINSPIRED ELASTOMER COMPOSITES WITH PROGRAMMED MECHANICAL AND ELECTRICAL ANISOTROPIES Article Open access 26 January 2022

ULTRAROBUST SUBZERO HEALABLE MATERIALS ENABLED BY POLYPHENOL NANO-ASSEMBLIES Article Open access 13 February 2023 HUMAN-MUSCLE-INSPIRED SINGLE FIBRE ACTUATOR WITH REVERSIBLE PERCOLATION

Article Open access 27 October 2022 DATA AVAILABILITY The datasets that support the finding of this study are available in ScholarSphere repository with the identifier(s)

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blends. _Soft Matter_ 6, 4807–4818 (2010). Article  CAS  Google Scholar  Download references ACKNOWLEDGEMENTS This work was supported by the Air Force Office of Scientific Research under the

Young Investigator Prize (award 18RT0680, R.J.H.), the National Science Foundation through the DMREF programme (CMMI 2119717, R.J.H.) and the Materials Research Institute seed grant from

The Pennsylvania State University (R.J.H.). M.K. was supported by National Science Foundation grant CBET 1946392 and DMREF programme CMMI 1627197. V.G. was supported in part by the Welch

Foundation (grant F-1599). This research used the Complex Materials Scattering beamline of the National Synchrotron Light Source II, a US Department of Energy (DOE) Office of Science User

Facility operated for the DOE Office of Science by Brookhaven National Laboratory under contract number DE-SC0012704. TEM, SEM, SAXS and WAXS measurements were taken at the Materials

Characterization Lab (MCL) in the Materials Research Institute (MRI) at The Pennsylvania State University. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * South China Advanced Institute for

Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou, China Chao Lang * Materials Science and Engineering, The Pennsylvania

State University, University Park, PA, USA Chao Lang, Elisabeth C. Lloyd, Kelly E. Matuszewski, Yifan Xu & Robert J. Hickey * Guangdong Provincial Key Laboratory of Functional and

Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou, China Chao Lang * McKetta Department of Chemical Engineering, The University of Texas at Austin,

Austin, TX, USA Venkat Ganesan & Manish Kumar * Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, TX, USA Rui Huang * Department

of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, TX, USA Manish Kumar * Materials Research Institute, The Pennsylvania State University,

University Park, PA, USA Robert J. Hickey Authors * Chao Lang View author publications You can also search for this author inPubMed Google Scholar * Elisabeth C. Lloyd View author

publications You can also search for this author inPubMed Google Scholar * Kelly E. Matuszewski View author publications You can also search for this author inPubMed Google Scholar * Yifan

Xu View author publications You can also search for this author inPubMed Google Scholar * Venkat Ganesan View author publications You can also search for this author inPubMed Google Scholar

* Rui Huang View author publications You can also search for this author inPubMed Google Scholar * Manish Kumar View author publications You can also search for this author inPubMed Google

Scholar * Robert J. Hickey View author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS C.L., M.K. and R.J.H. conceived the research. C.L. developed,

prepared and characterized materials. C.L. measured mechanical and actuation properties. E.C.L. and Y.X. conducted X-ray measurements. C.L. and K.E.M. analysed actuation properties using

video analysis. V.G. and R.H. developed the mechanical property model. C.L., M.K. and R.J.H. wrote the manuscript. R.J.H. supervised the research. All authors read and commented on the

manuscript. CORRESPONDING AUTHOR Correspondence to Robert J. Hickey. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing interests. PEER REVIEW PEER REVIEW INFORMATION

_Nature Nanotechnology_ thanks Xuanhe Zhao and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. ADDITIONAL INFORMATION PUBLISHER’S NOTE Springer

Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION Supplementary Figs. 1–22 and

Tables 1–5. SUPPLEMENTARY VIDEO 1 Linear actuation by heating. SUPPLEMENTARY VIDEO 2 Linear actuation by hydration. SUPPLEMENTARY VIDEO 3 An umbrella that automatically opens when applying

water. SUPPLEMENTARY VIDEO 4 Rotational actuation by hydration. SUPPLEMENTARY VIDEO 5 Rotational actuation by heating. SOURCE DATA SOURCE DATA FIG. 1 Source data for Fig. 1d SOURCE DATA FIG.

2 Source data for Figs. 2e–g, k SOURCE DATA FIG. 3 Source data for Figs. 3a–f SOURCE DATA FIG. 4 Source data for Figs. 4a–c,f RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS

ARTICLE CITE THIS ARTICLE Lang, C., Lloyd, E.C., Matuszewski, K.E. _et al._ Nanostructured block copolymer muscles. _Nat. Nanotechnol._ 17, 752–758 (2022).

https://doi.org/10.1038/s41565-022-01133-0 Download citation * Received: 06 October 2021 * Accepted: 02 April 2022 * Published: 02 June 2022 * Issue Date: July 2022 * DOI:

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