Bone and teeth as fibrous biological composites: in situ nano-mechanical investigations

骨骼和牙齿作为纤维生物复合材料：原位纳米力学研究

基本信息

批准号：
EP/E039928/1
负责人：
Asa Barber
金额：
$ 30.05万
依托单位：
Queen Mary University of London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2007
资助国家：
英国
起止时间：
2007 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FE039928%2F1
关键词：
Bone teeth fibrous biological composites

项目摘要

Man-made composite materials are used extensively in a variety of structures where high strength and stiffness is required as well as low weight. These composites are almost exclusively constructed from a lightweight polymer reinforced with fibres. The fibres have advantages over other geometries as the mechanical properties are excellent in one particular direction, making the fibre anisotropic. The numerous structures existing in nature are optimized through evolutionary processes for a particular mechanical function. Common examples of biological materials with a mechanical role are bone, required for structural integrity in skeletal systems, and teeth, primarily used for chewing and tearing of food. These materials have striking resemblances to man-made composites as fibrous constituents are used as reinforcement in an organic matrix. However, two main differences are apparent in biological composites when compared to synthetic composites. The first is that the reinforcing fibres in biological composites are much smaller than typical fibres used in engineering composites. Decreasing fibre diameter is widely acknowledged to increase strength and utilization of scale effects in nature highlights the optimization processes used. Furthermore, many organizational levels exist in biological composites from the nano-scale level of the reinforcing fibre building blocks up to the large scale architectures. This structural hierarchy is currently far more complex than any synthetic composite.Understanding how the nano-scale fibre building blocks influence the overall mechanical properties of the biological composite is experimentally challenging due to the structural hierarchy and small size of the fibre reinforcements. Mechanical tests on large samples give results that are difficult to interpret because of the various different fibre organizations. Therefore, testing on the individual nano-scale fibre reinforcements in biological composites would give fundamental information and help to understand how materials like bone and teeth are optimized for their mechanical functions. In addition, the understanding of biological composites at the nano-scale could provide a pathway for developing new synthetic composites with nano-material reinforcements.The project will test samples of bovine bone femur and limpet teeth, which are representative of many different types of bone and teeth found in nature. The nano-scale fibres will be mechanical tested by pulling at the ends of these fibres. The pulling will be done by a scanning probe microscopy, which is ideal for measuring the very small forces needed to deform and break the nano-scale fibres. An electron microscope will also be used to visualize these tests and observe if the nano-scale fibres are fractured during the pulling process or slide out of the surrounding organic matrix. Mechanical models used in conventional composite theory will be applied to assess the mechanical properties of the reinforcing nano-fibres and the surrounding organic matrix. The results of this research will therefore provide unique insight into how natural materials have remarkable mechanical properties from using nano-scale building blocks.

人造复合材料广泛用于各种需要高强度和刚度以及低重量的结构中。这些复合材料几乎是由用纤维增强的轻质聚合物构建的。纤维比其他几何形状具有优势，因为机械性能在一个特定的方向上非常出色，从而使纤维各向异性。自然界中存在的众多结构通过特定机械功能的进化过程进行了优化。具有机械作用的生物学材料的常见例子是骨骼，骨骼系统中结构完整性所必需的，牙齿主要用于咀嚼和撕裂食物。这些材料与人造复合材料具有惊人的相似之处，因为在有机基质中使用纤维组成部分。但是，与合成复合材料相比，生物复合材料中的两个主要差异是显而易见的。首先是，生物复合材料中的增强纤维比工程复合材料中使用的典型纤维小得多。纤维直径的降低被广泛认可，可以提高自然界的强度和比例效应的利用，突出了所使用的优化过程。此外，从增强纤维构建块的纳米级级别到大规模架构的生物复合材料中存在许多组织级别。目前，这种结构层次结构比任何合成复合材料都要复杂得多。理解纳米尺度纤维的构建块如何影响生物复合物的整体机械性能在实验上具有挑战性，这是由于结构性层次结构和纤维增强纤维的小尺寸。大型样品的机械测试给出了由于各种不同的纤维组织而难以解释的结果。因此，对生物复合材料中各个纳米级纤维增强的测试将提供基本的信息，并有助于了解如何对骨骼和牙齿等材料进行机械功能的优化。此外，对纳米级生物复合材料的理解可以为开发具有纳米材料增强的新合成复合材料提供途径。该项目将测试牛骨股骨和lim牙的样品，这些样品代表了许多在自然界中发现的许多不同类型的骨骼和牙齿。纳米尺度纤维将通过拉动这些纤维的末端进行机械测试。拉力将通过扫描探针显微镜完成，这是测量变形和破坏纳米尺度纤维所需的很小力的理想选择。电子显微镜还将用于可视化这些测试，并观察纳米尺度纤维在拉动过程中是否骨折或滑出周围有机基质。传统复合理论中使用的机械模型将应用于评估增强纳米纤维和周围有机基质的机械性能。因此，这项研究的结果将提供独特的见解，了解天然材料如何使用纳米级构建块具有显着的机械性能。