若干典型动物牙齿的生物摩擦学机理研究

After long evolution, different animal teeth have their unique geometry and anatomy to adapt to different living environments, and then form various biotribological systems with excellent wear resistance. How these tribological systems work has not been well known. This research project is to explore the biotribological behaviors and friction-regulated mechanism of teeth from several typical animal species, and then investigate the bionic design based on animal teeth. The structures and mechanical performances of these animal teeth will be systematically characterized, and those tribological behaviors will be studied by in situ testing and in vitro simulation testing. Hence, the effects of severe oral conditions (such as rigid hybrid food, strongly acidic medium, etc.) and complex structural factors (such as flexible tooth shape, multi-scale hierarchical structure, etc.) on the tribological performance of animal teeth will be investigated. And meanwhile, living bamboo rats will be raised and used in this study. The microstructure and mechanical properties of their opposing incisor teeth under different oral occlusal loading and friction conditions will be tested and compared so as to reveal the regulatory influence of interface friction on the growth of dental tissues. On the basis of experimental results and biostatistics analysis, the formation mechanism of dental friction pair will be analyzed and summarized, and then some bionic design criteria based on animal teeth will be proposed. This study would help not only explore natural mysteries and develop bio-tribology, but also establish theoretical and technical support for the bionic design of anti-wear engineering systems.

动物牙齿经过漫长进化形成了特有的适应环境的几何形态和解剖学结构，构成了具有优异耐磨性能的天然生物摩擦学系统，而人们对其服役行为知之甚少。本项目拟针对若干典型动物牙齿的生物摩擦学行为与调控机理、仿生学设计展开研究。通过对动物口颌系统的生物力学分析、牙齿组织结构和机械性能的系统表征、不同食性动物牙齿摩擦学行为的体内/外模拟实验研究，揭示恶劣受力环境（高硬混杂食物、强酸性介质等）及复杂结构因素（形状多变、跨尺度多级结构等）对牙齿摩擦学行为的影响机制；以活体竹鼠为重点研究对象，考察不同受力环境下竹鼠门牙的微观结构和机械性能，研究界面摩擦对牙齿组织结构演变的调控机理；在此基础上，结合生物统计学分析，揭示动物牙齿耐磨功能的形成机制,提出基于动物牙齿的摩擦学仿生设计准则。本项研究不仅对探索自然界的奥秘、丰富和发展生物摩擦学学科理论体系具有重要理论价值，而且为工程耐磨器件的仿生设计提供理论基础与技术支撑。

动物牙齿经过漫长进化形成了特有的适应环境的几何形态和解剖学结构，构成了具有优异耐磨性能的天然生物摩擦学系统，而人们对其服役行为知之甚少。因此，本项目系统开展了典型动物牙齿的摩擦学构性关系研究、典型动物牙齿的酸蚀与自修复行为研究、界面摩擦对动物牙齿结构与性能的调控机理研究和基于动物牙齿的摩擦学仿生设计研究。.结果显示，动物牙釉质的摩擦学构性关系与食性之间存在自适应性，肉食动物牙釉质中较软的釉间质能提高其对于高负荷的耐受性以适应高咬合力，而草食动物牙釉质的高硬度和纳米纤维束十字交叉结构能有效抵抗裂纹扩展以适应长时间咀嚼，其中，微量蛋白质组分调控牙釉质的跨尺度多级结构结构以提高其耐磨性，并通过应力诱导表面硬化提供自适应过载保护；牙釉质的耐酸蚀能力与其表面微观结构存在明显相关性，横向排布的羟基磷灰石纳米纤维束有助于提高酸蚀耐受性，此外，咬合冲击能促进牙釉质酸蚀表面的再矿化修复作用；机械刺激能够改变竹鼠牙釉质生长发育过程中造釉细胞的排布，提高牙齿矿化程度，影响牙齿微观结构的致密性与有序性，并与其元素成分（尤其是铁元素）密切相关；基于牛磨牙齿坎结构设计了仿生磨头，基于竹鼠切牙的“月牙洼”结构设计了用于切削铝合金的变深度梯度微织构车刀和用于切削碳纤维复合材料的弧形前刀面（断屑槽）车刀，基于肉食动物犬齿弯曲轴线特征研制了一种盾构/TBM斜齿滚刀刀圈，基于天然牙微纳观摩擦学构效关系开发了金沙古象牙的纳米羟基磷灰石仿生修复。.本项目研究不仅对探索自然界的奥秘、丰富和发展生物摩擦学学科理论体系具有重要理论价值，而且为工程耐磨器件的仿生设计提供理论基础与技术支撑。项目在研期间，发表了一批与研究内容相关的论文；获批教育部自然科学奖一等奖和四川省科技进步奖一等奖各一项；申请并授权了一批专利；培养了一批博士、硕士和青年教师；积极进行国际合作与交流，获批高等学校学科创新引智计划“生物摩擦学与仿生制造学科创新引智基地”。