National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
J Struct Biol. 2011 Apr;174(1):31-6. doi: 10.1016/j.jsb.2011.01.001. Epub 2011 Jan 11.
In the natural world, bottom-up hierarchical construction of complex structures results in materials with remarkable properties. A well known example is the nacre of mollusk shells, commonly called "mother of pearl", whose excellent strength and toughness has been the subject of research for many decades. A significant discovery has been the presence of periodic layers called "growth lines". These are thin distinct layers within the bulk of the shell which form periodically, with their structure affected by environmental changes. Studies of their formation and behavior offer valuable insight into the architecture of seashells. In this work, the structure and mechanical behavior of growth lines in shells of abalone Haliotis gigantea were investigated using electron microscopy and nanoindentation. Growth lines form directly out of nacre into layers of blocks and irregular particles. In comparison to nacre, they have basic structures, form rapidly, and are harder, which suggest that they serve a protective role during lifecycle transitions. This exemplifies how natural structures are able to closely control growth architecture in order to form different structures for different functions, all from the same base materials.
在自然界中，复杂结构的自下而上的层次结构导致了具有显著性能的材料的出现。一个著名的例子是软体动物贝壳的珍珠母，其优异的强度和韧性已经成为几十年来研究的主题。一个重要的发现是存在周期性的层，称为“生长线”。这些是在贝壳的主体内形成周期性的薄而明显的层，其结构受环境变化的影响。对它们的形成和行为的研究为研究贝壳的结构提供了有价值的见解。在这项工作中，使用电子显微镜和纳米压痕法研究了鲍鱼 Haliotis gigantea 壳中的生长线的结构和力学行为。生长线直接从珍珠母形成层状的块和不规则的颗粒。与珍珠母相比，它们具有基本的结构，形成迅速，而且更硬，这表明它们在生命周期转变期间起到了保护作用。这说明了自然结构是如何能够紧密控制生长结构，以便为不同的功能形成不同的结构，所有这些都是从相同的基础材料中实现的。
