High-performance composites with bio-inspired interlocking aperiodic monotiles

Structural composites integrating a stiff material with a ductile soft phase offer an effective pathway to overcome the long-standing trade-off among stiffness, strength, and toughness in mechanical metamaterials. Current soft-hard material arrangements are predominantly limited to conventional periodic patterns with straight edges, constraining further enhancement of composite mechanical performance. Here we develop a novel aperiodic monotile composite with bio-inspired interlocking edges. A comprehensive experimental and numerical study demonstrates that our design exhibits substantial improvement in fracture resistance. Specifically, the proposed composite achieves a twentyfold improvement over the conventional honeycomb composite, performs six times better than the aperiodic monotile composite with straight edges, and shows a further 148% increase relative to the semicircle-edge counterpart. The underlying mechanisms of these enhancements arise from the synergy between the globally optimized stress distribution enabled by aperiodicity and the strong mechanical interdigitation and constraint created by the bio-inspired interlocking edges. Overall, this study opens an innovative avenue toward advanced composite design by combining bio-inspired interlocking geometry with aperiodicity.