Herringbone structure rotates crack propagation. Purdue/UCR research.
Mantis shrimp possess the most powerful punch in the animal kingdom, striking prey at speeds exceeding 15 metres per second with forces equivalent to a bullet. Their dactyl club—a sophisticated bludgeoning structure—achieves this performance through layered hierarchical architecture where keratinous fibres are arranged in progressively rotated herringbone patterns. This spiral arrangement redirects crack propagation paths, prevents catastrophic failure, and distributes impact energy across multiple material interfaces. The dactyl club suffers damage from repeated impacts yet maintains structural integrity for thousands of strikes—a self-healing resilience unmatched in conventional materials. Materials scientists at Purdue and UC Riverside studied mantis shrimp club architecture and recognised that herringbone fibre arrangements could create impact-resistant composites superior to existing aerospace and military materials. By arranging reinforcement fibres in spiral-rotated layers, researchers engineered composites that progressively rotate crack propagation paths, dissipating impact energy through multiple failure modes rather than catastrophic fracture. These mantis-shrimp-inspired composites achieve impact strength 30% superior to carbon fibre whilst using lower-cost base materials, revolutionising how engineers approach damage tolerance in high-impact applications.