Bone-Inspired Materials by Design: Toughness Amplification Observed Using 3D Printing and Testing

Inspired by the fact that nature provides multifunctional composites by using universal building blocks, the authors design and test synthetic composites with a pattern inspired by the microstructure of cortical bone. Using a high‐resolution multimaterial 3D printer, the authors are able to manufacture samples and investigate their fracture behavior in mechanical tests. The authors’ results demonstrate that the bone‐inspired design is critical for toughness amplification and balance with material strength. The failure modes of the authors’ synthetic composites show similarities with the cortical bone, like crack deflection and branching, constrained microcracking, and fibril bridging. The authors’ results confirm that our design is eligible to reproduce the fracture and toughening mechanism of bone. Nature uses few universal building blocks to achieve multi‐functionality and amplification of mechanical properties through different hierarchical structures. With a similar approach, it is possible to use pure polymers as building blocks to investigate, through bio‐inspired design and 3D printing, the effect of different geometrical features.