Chinese sturgeon (Acipenser sinensis) fish skin is an excellent natural material with remarkable mechanical properties owing to the unique structures of the helical stacking fibres. In this work, the authors studied the potential role of the sturgeon fish skin in the protective function through testing and analysed the structural features and mechanical properties of the stratum compactum in the fish skin. Scanning electron microscopy images of the sturgeon fish skin revealed that the skin was primarily composed of the stratum compactum. The stratum compactum was characterised by the helically arranged fibre structures and the helical-ply angle decreased from the anterior region of the fish body to the posterior region. Mechanical tests containing tension and penetration experiments demonstrated that the stratum compactum provided the sturgeon fish skin the capability to effectively resist bite and laceration by predators. Furthermore, the experimental results also confirmed that the sturgeon fish skin showed two distinct mechanisms against tension and penetration. These findings may provide a novel biomimetic design template for both flexible and tough body armour.

中文翻译：

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中华鲟（Acipenser sinensis）鱼皮的独特形态和力学性能。

中华鲟（Acipenser sinensis）鱼皮是一种优良的天然材料，由于其独特的螺旋堆叠纤维结构，具有显着的机械性能。在这项工作中，作者通过测试研究了鲟鱼皮在保护功能中的潜在作用，并分析了鱼皮中致密层的结构特征和力学性能。鲟鱼皮肤的扫描电子显微镜图像显示皮肤主要由致密层组成。致密层呈螺旋状排列的纤维结构，从鱼体前部到后部，螺旋层角逐渐减小。包含张力和穿透实验的机械测试表明，致密层为鲟鱼鱼皮提供了有效抵抗捕食者咬伤和撕裂的能力。此外，实验结果还证实，鲟鱼鱼皮表现出两种不同的抗张力和抗穿透机制。这些发现可能为灵活和坚韧的防弹衣提供一种新颖的仿生设计模板。