Fourier transform infrared spectroscopy of the saddle

The microstructure, chemical composition and mechanical strength of heterogeneous materials of mantis shrimp (Oratosquilla oratoria) saddle were studied. As the key component of the striking system, the saddle comprised two distinct layers including outer layer and inner layer. The outer layer contained blocky microtubules and exhibited compact appearance. The inner layer presented a typical periodic lamellar structure. Due to the change of the thickness of the mineralized outer layer, the organic multilamellar structure became the foundation and enhanced the connection strength (4.55 MPa) at the connect regions between the saddle and merus exoskeleton and membrane, respectively. In the process of fracture, the lamellar structure dispersed the stress effectively by the change of the crack deflection direction and the microfibrils ordered arrangement. The exploration of mantis shrimp saddle region is beneficial to understand the striking system and provided the possibility for the stable connection of heterogeneous materials in engineering fields. The microstructure, heterogeneous material connection characteristics and high mechanical strength of saddle provide bionic models for the preparation of fiber-reinforced resin composites and soft composites.

本研究针对螳螂虾（Oratosquilla oratoria）鞍部异质材料的微观结构、化学成分与力学强度展开了系统探究。作为该物种攻击系统的关键组件，鞍部具有两层截然不同的微观结构：外层与内层。外层由块状微管构成，外观致密规整；内层则呈现出典型的周期性层状结构。随着矿化外层厚度的变化，有机多层结构成为结构基础，并分别提升了鞍部与长节外骨骼、鞍部与膜结构之间连接区域的连接强度（达4.55 MPa）。在断裂过程中，层状结构可通过改变裂纹偏转方向与调控微纤丝有序排列，有效分散应力。对螳螂虾鞍部区域的探究，有助于深入理解其攻击系统的运作机制，同时为工程领域异质材料的稳定连接提供了可行思路。鞍部所具备的微观结构、异质材料连接特性与优异力学强度，可为纤维增强树脂基复合材料及柔性复合材料的制备提供仿生原型。