【作者】 周铭；

【导师】 温诗铸；

【作者基本信息】 清华大学 ， 机械工程， 2013， 博士

【摘要】 仿生技术极大改变了人类的社会和经济生活，启发了很多影响人类社会发展的仿生发明。作为自然界中对粘着和摩擦具有出色控制能力的代表，壁虎具有在墙壁和天花板行走自如的卓越的攀爬能力。基于这种粘着、爬行能力的仿生功能表面、爬壁机器人在反恐、搜救、侦查、太空定位、抓持、清洁等国家安全、工业技术、日常生活等领域具有深远的应用前景。研究其粘/脱附机理和仿生表面设计理论，对开发新一代干粘着功能表面及器件具有重要理论指导意义和实用价值。本文从剥离区域影响剥离性能及各向异性性能关系的角度对仿壁虎刚毛功能表面的设计理论及制备应用进行了研究，主要取得如下成果：发展了剥离区域的基本理论模型。建立了考虑速度效应的拓展剥离区域模型。使用此模型，可将剥离问题中的三个重要参数——剥离强度、剥离速度、剥离角度之间的关系在同一公式中进行描述。发展了强粘附、易剥离性能和集束行为的设计理论。建立了基于柱状纤维的仿壁虎刚毛表面剥离区域对剥离行为影响的数值计算模型，讨论了仿生表面的强粘附和易脱附特性的设计准则，发展了粘着、剥离设计图。通过优化结构参数，剥离力相比粘附力可以减小至少三个数量级。还对微纳米纤维阵列表面的集束行为进行了研究，使用两个无量纲参数对临界集束行为判据进行描述，建立了集束稳定性评价准则。讨论了倾斜碳纳米管阵列剥离区域变形对其各向异性性能的影响。制备了倾斜多壁碳纳米管阵列表面，实验表明其具有40%的稳定的摩擦各向异性性能。观测并描述了卸载过程中与壁虎刚毛类似的各向异性粘附摩擦现象，并考虑碳纳米管末梢的接触变形，建立了基于范德华相互作用力的摩擦各向异性理论模型。设计出一种基于仿壁虎刚毛表面的夹持器原型机。对具有末端薄板结构的蘑菇状纤维阵列仿壁虎刚毛表面进行了性能表征和设计评价，为仿生表面在夹持器上的应用提供了理论和实验依据。进而设计了一种用于硅片等轻质、易碎物体转移搬运的小型夹持器，实现了粘着力的有效控制，对推进仿壁虎刚毛表面在智能仿生粘附器件上的应用具有重要意义。更多还原

【Abstract】 The bio-inspired technology has inspired lots of important inventions and greatlychanged the society of the human being. With outstanding capability of adhesion andfriction control, gecko can move on the surfaces of the walls and ceilings rapidly. Thegecko-inspired functional surface and then the wall-climbing robot have great potentialand wide application prospect in the area of national security, industry and daily lifesuch as counter-terrorism, rescue, detection, space positioning, cleaning in tall buildings,etc. Therefore, the research on the mechanism of attachment and detachment and thedesign principles are very important to developing the new generation of dry adhesivefunctional surface and device in both theoretical and practical applications. Based on theeffect of peel zone on the peeling behavior and the anisotropic property, the principle ofdesign and application of bio-inspired surface has been researched in this study.First, the basic theoretical peel zone model is developed, with the consideration ofthe peel velocity effect. Peel strength, peel velocity and peel angle, the three importantpeeling parameters, are described in the same analytical formula by the extended peelzone model.Second, the design principle of bio-inspired surface with the strong attachment buteasy removal properties and the anti-bunching behavior are developed. A numericalmethod was developed to evaluate the effect of peel-zone deformation on the peelingbehavior of fibrillar gecko-inspired surface. Based on the analysis of the peelingmechanical behavior, the design criterion of strong attachment and easy removalproperties is discussed. The optimum point is proposed by a new established adhesionand peeling design map, which is determined by the competition of the strong adhesiveproperty and the easy-removal property, being consistent with the allowed parameterrange of the biological contact elements qualitatively. By taking the typical values ofparameters, the adhesion force and the peeling strength can be changed in three ordersof magnitude. Further, the bunching behavior of micro-and nano pillar array surface isstudied. The two dimensionless parameters are proposed to evaluate the criterion ofbunching. Also the evaluation criterion of the stability of bunching is established.Then in order to discuss the relationship between the anisotropy and thedeformation of the peel zone, the gecko-inspired surface is prepared with inclined multiwall carbon nanotube array, which has typical40%steady anisotropic interfacialfriction property. The tribological characterization of the inclined CNT array surface istested experimentally. Also the anisotropic adhesional friction is observed in theunloading process. Furthermore, the anisotropic behavior is quantitatively modeled andexplained based on the van der Waals interaction.Finally, a prototype of clamp holder based on gecko-inspired surfaces has beendesigned and tested. On the basis of the experimental mechanical characterization andthe theoretical design evaluation of the mushroom like fibrillar gecko-inspired surface,the clamp holder designed specifically to the lightweight and fragile objects is realizedand fabricated, which provides new insights into the application of gecko-inspiredsurface on the intelligent adhesion devices.更多还原