In nature, bone adapts to mechanical forces it experiences, strengthening itself to match the conditions placed upon it. Here we report a composite material that adapts to the mechanical environment it experiences—varying its modulus as a function of force, time and the frequency of mechanical agitation. Adaptation in the material is managed by mechanically responsive ZnO, which controls a crosslinking reaction between a thiol and an alkene within a polymer composite gel, resulting in a mechanically driven ×66 increase in modulus. As the amount of chemical energy is a function of the mechanical energy input, the material senses and adapts its modulus along the distribution of stress, resembling the bone remodelling behaviour that materials can adapt accordingly to the loading location. Such material design might find use in a wide range of applications, from adhesives to materials that interface with biological systems.
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We thank M. Garg for performing the μCT imaging and S. C. W. Huang for the helpful discussion. Parts of this work were carried out at the Soft Matter Characterization Facility, the FIB-SEM facility of the University of Chicago and the SPID facility of Northwestern University’s NUANCE Center. The work was supported by AFOSR COE 5‐29168, NSF CHE‐1710116 and ARO W911NF‐17‐1‐0598 (71524‐CH). We dedicate this paper to Prof. Scott White who served as both an inspiration for this work and a personal inspiration for the authors.
The authors declare no competing interests.
Peer review information Nature Materials thanks Stephen Craig and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Wang, Z., Wang, J., Ayarza, J. et al. Bio-inspired mechanically adaptive materials through vibration-induced crosslinking. Nat. Mater. (2021). https://doi.org/10.1038/s41563-021-00932-5