基于金属微纳枝晶表面双电层电容式压力响应原理的水凝胶基水下柔性电子皮肤构建及其流体水动力学检测性能研究

Future development of underwater robot calls for soft bodies with bionic design instead of rigid members. Under this new trend, flexible electronic skins that can excellently match with the underwater soft systems are in urgent need. To overcome the problems existing in the current researches such as the lack of flexibility and bionic ability, as well as insufficient sensitivity, this project aims at the synthesis and applications of hydrogel based electronic skin with high flexibility, bio-imitability, sensitivity, as well as large area perception. By introducing the electric double layer theory into hydrogel nanocomposite, a novel mechanism that electric double layer capacitance formed on nanoporous microelectrode can respond to pressure changes is proposed. Accordingly, new methods for in situ electrochemical reduction in hydrogel are explored, and novel flexible electronic skin based on the composite material of metal nanodentrite/hydrogel are also designed and fabricated. By measuring in different types of fluid, the response performance of hydrogel electronic skin towards hydrodynamic information will be characterized. And the inner relationships between pressure disturbance generated by fluid, deformation of metal nanodentrite and the related capacitance change will be clarified by simulation study on the deformation of metal nanodendrites under different pressure distributions, which can provide basis for the design and fabrication of hydrogel electronic skin. Eventually, novel research ideas, materials, technology and approach for the underwater flexible electronic skins can be expected through the study of this project.

为顺应未来水下机器人柔性化、仿生化的发展大趋势，针对目前适用于水下柔性机器人的电子皮肤仍存在的柔性不足、仿生度不高、响应性有待提高等一系列问题，拟研发全柔性、高仿生、超灵敏、可大面积感知的新型水凝胶基水下电子皮肤。将双电层理论基本原理扩展到纳米复合水凝胶中，提出多孔微纳电极表面双电层电容值响应压力变化新机理，探索水凝胶内电化学原位还原新方法，设计制造新型金属微纳枝晶/高分子水凝胶复合材料，并实现其器件化。通过对不同流体的实际测量，明确新型水凝胶基电子皮肤对流体水动力学信息的综合响应性能，并结合不同压力场下金属微纳枝晶的形变模拟研究，揭示流体产生的压力扰动、金属微纳枝晶形变及双电层电容变化这三者之间的构效关系，为水凝胶电子皮肤的设计制造提供理论依据。并最终为水下柔性电子皮肤研究贡献新思路、新材料、新方法。

水下软体机器人能够模仿水生生物的柔软形体及运动机理，在水下侦查、海洋环境考察、资源探测及开发等领域具有广泛的应用前景。为赋予水下软体机器人对周围环境的感知能力，迫切需要发展与之相匹配的仿生柔性电子皮肤。本项目提出发展基于金属微纳枝晶/高分子水凝胶新型复合材料的水下柔性压力传感器。首先，通过多尺度的凝胶网络结构设计，利用氢键、离子键及疏水相互作用等物理交联方式，合成了具有耐拉压性、高韧性、耐疲劳及自愈合特性的新型水凝胶材料，解决了传统水凝胶材料由于自身脆弱的力学性能而无法承受机械载荷的问题。其次，通过原位电还原法实现了水凝胶内金属微纳枝晶的可控生长，探明了反应参数条件对金属微纳枝晶分形结构形貌的影响规律，并发现了金属微纳结构的引入使得水凝胶薄膜具有了各向异性的退溶胀特性，进而通过金属微纳枝晶在水凝胶表面植入区域的图案化设计，实现了对水凝胶形变行为的精准调控，并将其应用于水凝胶驱动器的构建。此外，在水凝胶器件化的研究中，发现了制约水凝胶器件组装的一个基础性问题，即如何在水凝胶与一系列异质材料如金属、陶瓷、弹性体、塑料、生物组织等界面间形成强韧粘接，从而实现不同材料的集成。通过在界面引入一层光响应的离子交联聚合物网络，与粘接物自身网络间形成拓扑缠结，实现了水凝胶材料与不同基底材料界面间强韧的光响应可拆卸粘接；并提出了一种新的“分子缝合-锚固”粘接机理，利用儿茶酚化学制备了一种通用型胶水，简单快速地实现了水凝胶材料与一系列不同基底材料界面间的强韧粘接。最后，探究了金属微纳枝晶/高分子水凝胶复合材料的器件化，并探索了其对水下压力信号的响应性，基本实现了对水下低频压力信号的响应。