Despite being highly mineralized, the shells of molluscs exhibit superior strength and toughness because their architectural designs control the evolution of cracks and other types of localized deformation such as shear bands. The crossed-lamellar design of the shell of , whose hierarchy consists of four distinct lamellar-shaped features assembled in a three-dimensional arrangement, represents the toughest of all seashells. A mechanical metamaterial that adapts the geometrical design of this queen conch is anticipated to circumvent the typical trade-offs between strength-ductility and strength-density. Inspired by the three-dimensional hierarchical and interactive architecture of the crossed-lamellar microstructure, we instruct the design of bio-inspired metamaterials that mitigate failure from the extension of a single shear band and instead develop numerous smaller bands confined within the individual plank-like zones introduced in their layered geometric design. The measured strength properties of these materials are found to increase in inverse proportion to the square root of the thickness of the layers in the hierarchy as a result of progressive deformation enabled by cross-layer interactions. The results provide a new perspective on the design of strong and tough mechanical metamaterials.

中文翻译：

---

受 Strombus gigas 外壳启发的异质结构机械超材料

尽管高度矿化，软体动物的壳仍表现出卓越的强度和韧性，因为它们的结构设计控制了裂缝和其他类型的局部变形（例如剪切带）的演变。贝壳的交叉层状设计，其层次结构由四个不同的层状特征组成，以三维排列方式组装，代表了所有贝壳中最坚硬的。适应该女王海螺几何设计的机械超材料预计将避免强度-延展性和强度-密度之间的典型权衡。受交叉层状微结构的三维分层和交互架构的启发，我们指导仿生超材料的设计，该超材料可以减轻单个剪切带延伸造成的失效，而是开发出许多限制在单个板状结构内的较小带。分层几何设计中引入的区域。发现这些材料的测量强度特性与层次结构中各层厚度的平方根成反比增加，这是由于跨层相互作用引起的渐进变形的结果。研究结果为强韧机械超材料的设计提供了新的视角。