固体与刚毛结构间的生物电/摩擦电耦合黏附机制及仿生基础

The roles and behaviors of mechanical interaction between two solids are the fundament of modern mechanical engineering. The interactions in normal and tangential direction are generally repulsive and friction forces, but in many cases, attractive force is needed between two surfaces. Inspired by the moving ability of animals, such as geckos and flies, whose animal can move on various inclined surfaces, human would like to develop controllable adhesive technology to meet the requirement from engineering. The study would greatly extend the area of contact mechanics and set up bases for innovating new technology. The applicant combines the strong research groups in China and abroad and proposes an idea “adhesive mechanism coupling bioelectricity with tribo-electrification between solid and hairy-array”. The target of the project is to reveal the adhesive mechanism by coupling bioelectricity and tribo-electrification from animals (such as gecko) with hairy pads, to set up principles for bionic design on dry adhesive, to develop new functional device and manufacture technology. We are going to develop a new equipment which can measure the bioelectricity of flexor and extensor muscles on toe of gecko, the tribo-electrification between seta of gecko and substrate and the adhesive force simultaneously; to study the relations among the micro-structure of seta, adhesive forces, molecular structure and the tribo-electricity; to study the influence of circumstance, normal force and relative speed on the tribo-electricity and adhesive forces; to set up controlling relationship of adhesive pads; to develop fabrication technique of nano-adhesive array for the materials with high tribo-electrcity performance. The project will establish innovation abilities in the area and support the development of new technology for astronautics in orbit service

固体的表面/界面力学行为是现代机械工程的重要基础。通常固体界面传递法向排斥力和摩擦力，但很多场合需要能传递吸引力。受壁虎等动物在各种表面黏附运动的启示，实现固体间可调控的黏附接触，将拓展接触力学研究领域、为新技术发展奠定基础。申报人经多年研究思考，联合国内外优势团队，提出刚毛干黏附的生物电和摩擦电耦合协调机制的假说。课题目标：揭示壁虎等动物的黏附力生物电/摩擦电耦合协调机制，建立干黏附仿生设计新原理，发展干黏附功能材料器件的制备和应用技术。研究内容：研制同步测定壁虎脚趾屈肌和伸肌生物电、刚毛黏附摩擦电和黏附力的新仪器。确定动物黏附刚毛的结构与黏附力，及材料分子结构和摩擦致电的强度和正负的关系。研究环境、摩擦速度和力与摩擦致电强度及黏附力的关系，建立黏附接触的耦合调控基础。研究高摩擦电效应材料的纳米刚毛阵列制造技术。课题研究将奠定我国在该领域的自主创新能力，为航天在轨服务等奠定原理和技术基础

本项目旨在研究固体与刚毛结构间的生物电和摩擦电耦合黏附机制及仿生基础，开展了以下6方面的研究。（1）研制集成法拉第筒方法和电容法的接触/摩擦致电量和动物黏附力测试功能的实验装置，实现壁虎运动过程中接触作用力、接触面积和接触电荷的同步测量。（2）用上述装置实验测定动物黏附结构参数及黏附力的值与摩擦致电量间的关系，评估运动过程中接触电荷导致的静电力，得到壁虎脚掌层面上静电力和壁虎压舌板层面上的静电力对黏附的贡献。（3）测定壁虎黏/脱附过程生物电的变化规律，揭示生物电即屈肌-伸肌的拮抗肌电对黏/脱附的影响，发现生物电和摩擦电的协调耦合关系。通过研制的无线肌电信号采集系统来研究壁虎爬坡运动过程中特征信号之间的关联特性；并开展壁虎中脑细胞的免疫组织化学研究来探索黏附爬行时四肢协同的神经调控机制。（4）计算研究了材料分子结构与摩擦电的关系及摩擦参数的影响规律。研究壁虎刚毛与固体表面接触起电性能及电荷转移机制；研究了碳基仿生黏附材料与金属表面接触起电微观机理；探索金属表面间及聚合物与金属表面间的接触起电机理并分析致电性能与材料结构的关系；研究载荷和接触频率等因素对接触起电的影响；建立固体表面接触分离带电量模型，并进行实验验证。（5）探索仿生刚毛阵列的制备和修饰技术，获得基于新机制的干黏附刚毛结构及其制造技术。实现了仿生刚毛阵列的可控制备，并量化了制备工艺参数对其结构与黏附性能的影响；设计不同的碳纳米管等离子体接枝修饰技术及黏附性能测试；研究接触/摩擦电效应和外加电场下的黏附材料黏附性能，验证并量化了黏附过程中的接触/摩擦电效应。（6）研究基于生物电-摩擦电耦合调控的黏附功能部件的控制策略。提出了双向气压驱动的软体空腔结构及黏附装置的设计方案，通过建立结构模型及相应的力学仿真分析来研究结构参数与仿生结构力学响应特征间的关系，并进行优化和性能验证。进一步开展了航天黏附捕获及动力学相关研究。