CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230052, China.
Department of Engineering Mechanics, School of Civil Engineering, and State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China.
ACS Appl Mater Interfaces. 2021 Apr 21;13(15):17380-17391. doi: 10.1021/acsami.1c02867. Epub 2021 Apr 6.
The tail spike of the mantis shrimp is the appendage for counteracting the enemy from behind. Here, we investigate the correlations between the chemical compositions, the microstructures, and the mechanical properties of the spike. We find that the spike is a hollow beam with a varying cross section along the length. The cross section comprises four different layers with distinct features of microstructures and chemical compositions. The local mechanical properties of these layers correlate well with the microstructures and chemical compositions, a combination of which effectively restricts the crack propagation while maximizing the release of strain energy during deformation. Finite element analysis and mechanics modeling demonstrate that the optimized structure of the spike confines the mechanical damage in the region near the tip and prevents catastrophic breakage at the base. Furthermore, we use a 3D printing technique to fabricate multiple hollow cylindrical samples consisting of biomimetic microstructures of the spike and confirm that the combination of the Bouligand structure with radially oriented parallel sheets greatly improves the toughness and strength during compression tests. The multiscale design strategy of the spike revealed here is expected to be of great interest for the development of novel bioinspired materials.
螳螂虾的尾刺是用来抵御来自后方敌人的附属物。在这里，我们研究了刺的化学成分、微观结构和机械性能之间的相关性。我们发现，刺是一种具有沿长度变化的横截面的空心梁。横截面由四个不同的层组成，每个层都具有独特的微观结构和化学成分特征。这些层的局部机械性能与微观结构和化学成分密切相关，这种组合有效地限制了裂纹的扩展，同时在变形过程中最大限度地释放应变能。有限元分析和力学模型表明，刺的优化结构将机械损伤限制在尖端附近的区域，并防止在底部发生灾难性的断裂。此外，我们使用 3D 打印技术制造了多个由刺的仿生微观结构组成的空心圆柱形样品，并证实了 Bouligand 结构与径向取向的平行片的组合大大提高了压缩测试中的韧性和强度。这里揭示的刺的多尺度设计策略有望为新型仿生材料的开发带来很大的兴趣。
