Perricone Valentina, Cesarano Pasquale, Deb Mainak, Lublin Derek, Mutalipassi Mirko, Pappalardo Lucia, Kisailus David, Marmo Francesco
Department of Materials Science and Engineering, University of California Irvine, Irvine, CA, USA.
Department of Structures for Engineering and Architecture, University of Naples Federico II, Napoli, Italy.
R Soc Open Sci. 2025 Jun 25;12(6):241439. doi: 10.1098/rsos.241439. eCollection 2025 Jun.
The sea urchin skeleton is a lightweight yet load-bearing hierarchical structure composed of calcitic plates with a species-specific three-dimensional (3D) trabecular meshwork known as stereom. Interestingly, the stereom architecture is extremely complex and variable in different basic types, each one characterized by a unique geometry and structural behaviours. The present study provides an in-depth analysis of the microarchitectural variability in the sea urchin . Accordingly, micro-CT scans, image analysis, 3D modelling, mean intercept length and linear elastic finite-element analysis were conducted to provide the first comprehensive insights on the structural variability of the different stereom types, their anisotropy and their mechanical behaviour calculated for tensile and shear loading. The findings demonstrate distinct structural adaptations, with anisotropic stereoms specializing in directional stress transfer and more isotropic stereoms facilitating a uniform stress distribution. These results provide critical insights into the mechanical functions of stereom variability and support bioinspired designs for lightweight and strong materials.
海胆骨骼是一种轻量但能承重的分层结构，由钙质板组成，具有特定物种的三维（3D）小梁网络，称为立体结构。有趣的是，立体结构在不同基本类型中极其复杂且多变，每种类型都具有独特的几何形状和结构行为。本研究对海胆的微观结构变异性进行了深入分析。因此，进行了微型计算机断层扫描（micro-CT）、图像分析、三维建模、平均截距长度和线性弹性有限元分析，以首次全面了解不同立体结构类型的结构变异性、各向异性以及它们在拉伸和剪切载荷下的力学行为。研究结果表明了明显的结构适应性，各向异性的立体结构专门用于定向应力传递，而更具各向同性的立体结构则有助于应力均匀分布。这些结果为立体结构变异性的力学功能提供了关键见解，并支持了对轻质且坚固材料的仿生设计。
