Bioinspired materials with self-adaptable mechanical properties and self-regeneration

Nature produces outstanding materials for structural applications such as bones and wood that can adapt to their surrounding environment. For instance, bone regulates mineral quantity proportional to the amount of stress. It becomes stronger in locations subjected to the higher mechanical loads. This leads to the formation of mechanically efficient structures for optimal biomechanical and energy-efficient performance. However, it is a challenge for synthetic materials to change and adapt their structures and properties to address the changes of loading conditions. To address the challenge, we are inspired by the findings that bones are formed by mineralization of ions from blood onto scaffolds. We report a material system that triggers mineral synthesis from ionic solutions on organic scaffolds upon mechanical loadings and/or damages so that it can self-adapt to mechanical loadings and regenerate upon damages. For example, we observed ~30% increase in the modulus of the material upon periodic loadings for 3 days. We also observed that the material could self-repair damages generated by removing ~5 μm thick minerals from the matrix, in 7 days. We envision that our findings can open new strategies for making synthetic materials with self-adaptability and self-repair capability.