具有电致变色/电致动功能的柔性仿生材料的双重响应机制研究、性能调控及其器件设计

Materials and devices with the ability of reversible color and shape transformation following the environment changes have clear application prospects in the field of visible light camouflage and artificial intelligence. However, the current color-/shape-change dual-responsive devices usually controlled and stimulated by gas, light and magnetism have nonobvious dual-responsive effect, poor coordination and difficulty to adapt to a varity of environments. In the previous research, the applicant found that the flexible electrochromic devices based on bilayer nanowire networks had the electrochemical actuation behavior and were expected to achieve rapid and significant color-/shape- change effect. However, due to rare similar reports, the mechanism and assembled principle are still not clear. A series of basic scientific problems about material design and performance control need to be solved. In this subject, the synchrotron radiation light source combined with various in situ characterization methods will be used to explore the sources of unbalanced force, analysis the corresponding relation between color changes and unbalanced forces, and obtain electrochemical actuation mechanism of electrochromic devices. Besides, by means of the calculation of strain and stress and utilization of a variety of composite materials, flexible solid-state devices with multi-color changes and designable deformation are prepared. Therefore, the implementation of this project will be helpful to deeply understand the electrochemical mechanism in the dual-responsive process, structure-activity relationship in conversion process between electricity and force, and the design principles of multilayer electrochemical flexible devices.

根据所处环境能够改变颜色和形状的材料和器件，在可见光隐身和人工智能领域有着明确的应用前景。但目前的变色变形双响应器件通常是利用气、光、磁等刺激源或控制手段，变色变形效果不明显、协调性差且难以适应多变的环境。申请者在前期研究工作中发现所制备的基于纳米线网络的柔性电致变色器件具有电致动响应行为，有望实现快速、显著的变色变形效果。但由于未见有类似的报道，其致动机理、组装原则仍不明晰，需要解决材料设计与性能调控方面的一系列基础科学问题。申请人拟利用同步辐射光源结合原位表征手段探究不平衡力的来源，解析活性材料颜色变化与不平衡力之间的对应关系，获得电致变色器件的致动产生机制；基于应力应变计算，利用多种材料复合与图案化设计，构建多色彩变化与可编辑变形的柔性固态器件。本项目的实施有助于深刻理解电致变色和电致动过程中的电化学作用机理、电-力转换中的构效关系、以及多层电化学柔性器件的设计原则。

根据所处环境改变颜色和形状的材料和器件对于提高人类军事隐身能力具有重要的学术意义，同时在人工智能等民用领域也具有重大的应用价值。但现有的变色变形双重响应材料或器件通常是利用气、光、磁等刺激源或控制手段，变色变形效果不明显、协调性差且难以适应多变的环境。本项目通过制备双纳米线网络电致变色器件，实现了快速、显著的变色变形效果。W18O49纳米线基双响应器在−0.9 V低电压驱动下，其弯曲角度在5 s内可以快速达到238°，同时伴随着颜色变化。本项目深入探究了其变色/变形双响应机理，明确了电致动效应的支配组分，阐明了电致变色/电致动过程中的微观结构演化规律，掌握了全固态柔性电致变色/电致动双响应器的设计原则。此外，本项目研究了多种类型电致变色材料的变色/致动双响应性能，实现了双响应器的多色彩 (红、绿、蓝)变化，并且实现了双响应器较好的循环稳定性，循环2000次后变色效果基本没有下降。通过微观结构设计 (纳米线取向)，也实现了双响应器的多种变色/致动效果，说明电致变色/电致动双响应器具有“可编辑”变形的应用前景。最后，通过对双响应器的宏观形状设计，实现了抓取物体等电致动动作。