Novel cuttlebone-inspired hierarchical bionic structure enabled high energy absorption

Bionic design is an effective strategy for obtaining lightweight, high-performance, and even multifunctional structures. Here, we found a novel hierarchical lamellar chamber microstructure in cuttlebone. To determine whether and how this cuttlebone-like hierarchical structure (CL-H) works on its mechanical properties, various lattices with CL-H cellular structure through digital light processing technique were designed and fabricated. Results showed that the CL-H lattice had excellent mechanical performances, achieving specific energy absorption up to a dozen times that of the non-hierarchical cuttlebone-like structure (CL) and triply periodic minimal surface structures. The CL-H lattices presented progressive failure behaviors depending on the numbers of sub-chambers. Furthermore, the mechanisms of energy absorption characteristic and failure behavior were systematically analyzed by combining microstructure examination and FEM simulation, and a schematic model was proposed. This study shed light on the design and engineering of advanced bio-inspired materials with excellent mechanical properties.