Morphology and porosity of the spines of the sea urchin Heterocentrotus mamillatus and their implications on the mechanical performance
Morphology and porosity of the spines of the sea urchin Heterocentrotus mamillatus and their implications on the mechanical performance
复制标题
DOI：
10.1007/s00435-017-0385-4
复制
发表时间：
2018-03-01
期刊：
影响因子：
1
通讯作者：
Nickel, Klaus G.
中科院分区：
文献类型：
--
作者：
Lauer, Christoph;Grun, Tobias B.;Nickel, Klaus G.
板岩海胆heterocentrrotus mamillatus Linnaeus， 1758的棘在单轴压缩下具有“优雅”的破坏行为，即使在高应变下也能耗散能量和抵抗高载荷，因此成为仿生研究的焦点。本文利用扫描电子显微镜、x射线微计算机断层扫描（A mu CT）和重力分析等方法，对板岩铅笔海胆（H. mamillatus）大原生棘中钙质小梁和气孔的组织结构进行了分析和定量。这项研究提供了整个脊柱孔隙度的详细分布，并表明部分脊柱的孔隙度比迄今为止认为的要高得多。棘猴高镁钙质体的中央部分（髓质）孔隙率为75% ~近90%。从这个最里面的结构，200多个径向排列，但通常是弯曲的小梁延伸到脊柱边缘。这个复杂的网状结构（辐射层）在基底截面上最清晰可见，并通过A mu CT扫描得到证实。辐射层孔隙度在40 ~ 70%之间，被致密生长层（孔隙度15 ~ 35%）不规则分隔。生长层分为近端生长层和远端生长层，单只动物的生长层数分别为3-14层和2-7层。这些生长层是毛猴棘的特征，并在其显著的力学性能中起主要作用。脊柱的孔隙度从基部到尖端增加。讨论了变异的生物学和力学意义。
Spines of the slate pencil sea urchin Heterocentrotus mamillatus Linnaeus, 1758, are in focus of biomimetic research as they feature a "graceful" failure behaviour under uniaxial compression dissipating energy and resisting high loads even after high strain. This study elucidates and quantifies the organization of calcitic trabeculae and pores in large primary spines of the slate pencil urchin H. mamillatus by image analysis from scanning electron microscopy, X-ray micro-computed tomography (A mu CT) and gravimetry. This study delivers a detailed distribution of porosities within the whole spine and shows that parts of the spines have a much higher porosity then hitherto thought. The central part (medulla) of the high-magnesium calcitic stereom of H. mamillatus spines has a porosity range of 75% to nearly 90%. From this innermost structure, more than 200 radially aligned, but often sinuous trabeculae extend to the spine rim. The structure of this complicated meshwork (radiating layer) is best seen in basal cross sections and was confirmed by A mu CT scans. The radiating layer has a porosity range from 40-70% and is irregularly separated by the dense growth layers (15-35% porosity). Growth layers were classified in proximal and distal growth layers with numbers ranging within a single animal between 3-14 and 2-7, respectively. These growth layers are characteristic for H. mamillatus spines and play a major role in their remarkable mechanical properties. The porosity of the spine increases from base to tip. Biological and mechanical implications of the variations are discussed.