Strong, Fracture-Resistant Biomimetic Silicon Carbide Composites with Laminated Interwoven Nanoarchitectures Inspired by the Crustacean Exoskeleton

Crustacean exoskeletons demonstrate exceptional mechanical efficiency owing to their intricate architectures. However, the translation of their underlying structural design to man-made material systems represents a challenge. Here we report the top-down fabrication using freeze casting of silicon carbide hybrid composites which contain a compliant phase and mimic the structure of crustacean exoskeletons. The composites display laminated interwoven nanoarchitectures that replicate the main structural design motifs of crustacean exoskeletons, i.e., the laminated arrangement, varying in-plane orientations, and three-dimensional interconnection by abundant nanointerconnectivities of constituents. The laminated interwoven nanoarchitectures create an enhancement in several extrinsic toughening mechanisms, specifically crack deflection/twisting and uncracked-ligament bridging, which results in increasing fracture resistance with crack extension, i.e., rising R-curve behavior, and outstanding strength-toughness combinations, especially as compared to layered composites. Our approach is feasible for the efficient fabrication of bioinspired composites mimicking crustacean exoskeletons and demonstrates a promising potential for the development of new synthetic lightweight structural materials with exceptional combinations of mechanical properties.