硅藻形体和鲨鱼皮同时直接参与下的微形貌复形与纳界面仿能集成制造

Manufacturing of biomimetic drag-reducing shark skin reflects the complexity of the internal structure and external morphology, the function-coupling of the internal and external surface layer as well as the interrelation of the structure, material and function. The curve morphology of shark skin has been replicated with high fidelity based on bio-replicated foming method. As to the fabrication of biomimetic complex-structure of shark skin, the diatom was selected as the conformation media to construct the curve morphology of shark skin and was used to secret mucus instead of vivo shark by means of its porous micro-nano structure. After solving of the shape-function fitting, material-interface matching and structure-scale control, the complex-structure drag-reducing model of shark skin was built and optimized. Taking into account the microscopic morphology-replicating and nanoscale interface-imitating, the integrated manufacturing method was conducted based on diatom and shark skin participated directly and simultaneously. Furthermore, the replication accuracy, imitation effect and drag reduction efficiency were used as indicators to evaluate its manufacturing processes and results. The research above provides theoretical and technical foundation for the establishing of the new "From the Organism，For the Organism" typed integration of bio-manufacturing and bionic manufacturing, and for the establishing of the new "Organism-by-Organism Forming" method involving a variety of organisms.

仿鲨鱼减阻结构制造体现出内部结构与外部形貌的复杂性、表层内外功能的耦合性以及结构、材料与功能的相关性。前期基于生物复制成形技术实现了鲨鱼表皮沟槽微形貌的高逼真复形。本项目以仿鲨鱼复合减阻结构制造为研究对象，以硅藻形体为构形介质，旨在以硅藻单体为基材构建仿鲨鱼沟槽微形貌同时，用其微纳多孔形体代替活体鲨鱼皮实现其泌液机能。在解决形体与功能的契合、材料与界面的匹配、结构与尺度的控制等问题基础上，构建并优化出基于硅藻形体的仿鲨鱼复合减阻结构模型，进而兼顾微形貌复形与纳界面仿能，探索并建立硅藻形体和鲨鱼皮同时直接参与下的仿鲨鱼复合减阻结构集成成形方法及工艺体系，并以复形精度、仿能效果、减阻效率为指标，对其成形质量和实用效果进行综合测量与评价。最终为建立"用生物形体构建生物形体，用生物机能仿生生物机能"的生物与仿生集成制造新模式和多种生物体同时直接参与下的仿生功能结构成形新方法提供理论与技术支持。

本项目在对鲨鱼皮耦合减阻机理进行探讨基础上，提出了“以仿鲨鱼复合减阻结构制造为研究对象，以硅藻微纳多孔形体为构形介质，旨在以硅藻单体为基材构建高逼真仿鲨鱼沟槽微形貌的同时，用硅藻微纳多孔形体代替活体鲨鱼皮实现其泌液机能，在微形貌复形的同时兼顾纳界面仿能”的研究思路。针对“硅藻微纳多孔形体的缓释微渗特性分析”，选择典型硅藻形体为研究对象，分析其单体大小、孔径大小及其分布规律、不同形体类型与其缓释微渗性能的关系规律；针对“仿鲨鱼微形貌与纳界面复合减阻结构模型构建及优化”，将上述硅藻形体与鲨鱼表皮沟槽微形貌及粘液纳界面进行尺寸与结构匹配基础上的优选，将现有减阻剂与鲨鱼表皮粘液及硅藻微孔做分子长链结构及尺寸方面的材质匹配，并据此对前期建立的仿鲨鱼复合减阻结构初级模型进行优化改进；针对“仿鲨鱼复合减阻结构微形貌复形与纳界面仿能集成制造”，首先根据鲨鱼盾鳞微形貌及排布规律，3D打印制作仿鲨鱼表皮盾鳞结构阴、阳模板，然后把硅藻土作为复形填料用以填充模具，进而采用酸蚀、烧结等多种硅藻土固化成形方法成形出基于硅藻土的仿鲨鱼复合减阻结构，为后续综合测试与减阻规律分析提供样件制备方法；针对“仿鲨鱼复合减阻结构样件综合测试与减阻规律分析”，以复形精度和仿能效果作为上述仿鲨鱼复合减阻结构集成成形方法的评价指标，对所制备的仿鲨鱼复合减阻结构样件进行相关测量和分析，利用电镜扫描观察内部构成，利用XRD衍射分析硅藻土固化成形过程中的组分变化，同时对体积密度、孔隙度、吸附性进行实验分析，从而确定最佳成形工艺方法及参数条件。本项目为微纳米仿生制造技术特别是基于“用生物形体来构建生物形体，用生物机能来仿生生物机能”即“From the Organism，For the Organism”的生物与仿生集成制造新模式，以及基于“多种生物体同时、直接参与下的仿生功能结构成形制造”即“Organism-by-Organism Forming”提供了方法和技术探索。