承载与黏附可控一体化的微结构阵列表面仿生力学研究

The biomimetic gecko climbing devices should have very important applications in the military and civil fields in the future. The previous studies mainly focus on the theoretical investigation of the mechanical mechanisms of geckos' strong adhesion or reversible adhesion, and the biomimetic fabrication of arrayed surfaces of strong adhesion or reversible adhesion. The difference with the actual applications is how to realize the integrated function of bearing capacity and controllable adhesion. Considering the bearing requirement for material strength and the controllable adhesion requirement for flexibility of the material, we put forward a new idea that is to fabricate microstructural arrayed surfaces with the integrated function of bearing capacity and controllable adhesion based on flexible composites. Flexible composites can be fabricated using silicone rubber as matrix and nanoparticles or nano-fibers as reinforced phases. The mechanical properties of silicon rubber matrix composites can be characterized experimentally and theoretically. Then, the non-linearly theoretical model of large elastic deformation can be established in order to disclose the mechanical mechanisms and find the major influencing factors of bearing capacity and reversible adhesion of the wedge-shaped micro-structural arrayed surfaces. Afterwards, the biomimetic surface can be fabricated experimentally based on the silicon rubber matrix composites. Experiments can then be carried out to test the adhesion and bearing capacities of the surface. Based on the experimental and theoretical analysis, the biomimetic design idea and the optimized preparation method of the microstructural arrayed surface are presented finally. All the results can provide theoretical and technical supports for the design of the biomimetic gecko climbing devices in the future and should also be helpful for the interdiscipline development of surface and interface mechanics.

仿壁虎攀爬装置在未来军事及民用领域都具有重要的应用前景。已有研究主要是理论揭示壁虎超强黏附与可逆黏附力学机制，及仿生制备超强黏附及黏附可逆的阵列表面，与实际应用需求的差距是如何实现承载与黏附可控一体化。综合考虑承载对材料强度的要求及可控黏附对材料柔度的要求，本项目提出基于柔性复合材料设计楔体状微结构阵列表面，实现承载及黏附可控一体化的新思想。以硅橡胶为基体，制备纳颗粒/纤维增强柔性复合材料，实验及理论表征硅橡胶基柔性复合材料的力学性能；建立非线性弹性大变形理论模型，揭示楔体状微结构阵列表面承载及黏附可控的力学机制及主要影响因素；进一步以硅橡胶基复合材料为基材，仿生制备楔体状微结构阵列表面，开展黏附及承载功能测试；结合实验及理论分析提出承载及黏附可控一体化的微结构阵列表面的仿生设计思想及优化制备方法。项目成果有望为未来仿壁虎攀爬装置的实现提供理论及技术支撑，亦有助于表界面力学的交叉发展。

仿壁虎攀爬装置在未来军事及民用领域都具有重要的应用前景。已有仿壁虎功能表面与实际应用需求存在一定的差距，主要问题是如何实现承载与黏附可控一体化。本项目的主要研究内容：（1）硅橡胶基柔性复合材料的实验制备及性能测试;（2）硅橡胶基柔性复合材料力学性能的理论表征;（3）基于硅橡胶基柔性复合材料的仿生阵列表面的黏附机制;（4）承载与黏附可控一体化仿生阵列表面的实验制备与性能表征。项目取得的重要结果包括：（1）实验设计并制备了高强-高韧纳米颗粒填充硅橡胶基柔性复合材料，揭示了高强韧的微观力学机制；（2）建立了考虑损伤的低阶应变梯度理论，预测了颗粒填充弹性基复合材料的拉伸与压缩力学性能，揭示了尺寸及损伤效应对颗粒填充复合材料力学性能影响的力学机制；（3）通过化学制备方法，引进增粘剂及表面改性的补强剂，实现了高强韧-强粘附纳米颗粒填充硅橡胶基柔性复合材料的制备；（4）建立了弹性颗粒填充非线性弹性大变形复合材料的新本构理论，预测了该类复合材料的宏观力学性能，与实验结果一致；（5）基于高承载-强粘附新型柔性复合材料，结合微结构阵列表面制备技术，制备了仿生楔体阵列功能表面，具有显著的各向异性粘附特征，各向异性粘附指数较已报道的楔体阵列表面具有显著优势。（6）建立了微结构阵列的大变形模型，理论预测了微结构阵列的变形形貌；进一步开展了类薄膜微结构的黏附撕脱行为研究，提出了同时预测界面强度与界面韧性的新方法；（7）开展了壁虎多级黏附组织的自清洁机制仿生研究，揭示了壁虎等生物实现自清洁的力学机理；（8）基于系列微结构阵列表面，设计并制备了系列功能表面与微型多足机器人，可实现重物的轻易捡起与释放，固、液颗粒的快速定向输运与定点转移，极端环境下爬行运动等。项目研究成果为未来仿壁虎攀爬装置及极端环境固液微颗粒输运提供理论基础与技术支撑。