State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, People's Republic of China.
Cambridge Graphene Center, Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK.
Nat Commun. 2018 Nov 15;9(1):4798. doi: 10.1038/s41467-018-07241-7.
Materials with synchronous capabilities of color change and actuation have prospects for application in biomimetic dual-stealth camouflage and artificial intelligence. However, color/shape dual-responsive devices involve stimuli that are difficult to control such as gas, light or magnetism, and the devices show poor coordination. Here, a flexible composite film with electrochromic/actuating (238° bending angle) dual-responsive phenomena, excellent reversibility, high synchronization, and fast response speed (< 5 s) utilizes a single active component, WO nanowires. From in situ synchrotron X-ray diffraction, first principles calculations/numerical simulations, and a series of control experiments, the actuating mechanism for macroscopic deformation is elucidated as pseudocapacitance-based reversible lattice contraction/recovery of WO nanowires (i.e. nanostructure change at the atomic level) during lithium ion intercalation/de-intercalation. In addition, we demonstrate the WO nanowires in a solid-state ionic polymer-metal composite actuator that operates stably in air with a significant pseudocapacitive actuation.
具有变色和致动同步能力的材料有望应用于仿生双重隐身伪装和人工智能。然而，颜色/形状双重响应的设备涉及到气体、光或磁等难以控制的刺激，并且设备的协调性较差。在这里，一种具有电致变色/致动（238°弯曲角度）双重响应现象、优异的可逆性、高同步性和快速响应速度（<5s）的柔性复合膜利用了单个活性组件——WO 纳米线。通过原位同步辐射 X 射线衍射、第一性原理计算/数值模拟和一系列对照实验，阐明了宏观变形的致动机制，即锂离子插层/脱插过程中 WO 纳米线的赝电容可逆晶格收缩/恢复（即原子级别的纳米结构变化）。此外，我们还展示了 WO 纳米线在固态离子聚合物金属复合致动器中的应用，该致动器在空气中稳定运行，具有显著的赝电容致动性能。
