蛛丝定向集水启发补丁银纳米线柔性透明电极及其智能开关行为研究

Silver nanowire-based flexible transparent electrodes (AgNW-based FTEs) is most promising among the alternatives appropriate for replacing indium tin oxide in flexible electronic. However, due to the high and unstable contact resistance between AgNWs in junctions, it is hard to fabricate high figure of merits (FOMs) of AgNW-based FTEs. Especially under the general trends of intelligent application of flexible electronic, it is in urgent need of finding a solution for increasing FOMs of AgNW-based FTEs. Inspired by directional water collection on spider silk, concerning the wettability difference and power-free self-driven transportation of droplets, we combine wettability difference between AgNWs and flexible substrates, power-free self-driven transportation of droplets driven by rapid evaporation under given conditions and photopolymerization of conducting polymer monomers in this study. Patch precursor consisting of highly volatile solvent and conducting polymer monomers directionally transports to junctions of AgNWs, followed by mild photopolymerization-patching to achieve low and stable contact resistance. The working mechanism and dynamical model of patch precursor droplets directionally transporting to junctions driven by rapid evaporation of solvent and material mechanism of patching increasing FOMs will be discussed. Moreover, in terms of intelligent application, basing on the intelligent ability of conducting polymers, the behavior and mechanism of intelligent switch of patched AgNW-based FTEs in respond to electrical stimulus will be investigated. This study opens up a new avenue and provides theoretical basis to fabricate high FOMs of AgNW-based FTEs as well as to intelligent application of flexible electronic.

在寻求适用于柔性电子的氧化铟锡替代者中，基于银纳米线（AgNW）的柔性透明电极最具有应用前景。但是AgNW-AgNW交汇区的接触电阻高且不稳定，导致电极的高品质难以实现。在柔性电子智能应用的大趋势下，电极的品质问题尤为突出，亟需解决。受蛛丝定向集水涉及浸润性差异和液滴无源自运输的启发，本项目结合AgNW与柔性基底的浸润性差异、液滴在特定条件下快速挥发驱动的无源自运输和导电聚合物单体的光聚合，基于高挥发性溶剂和导电聚合物单体的补丁液微液滴定向运输至交汇区后，温和光聚合补丁实现低值且高稳定性的接触电阻。本项目揭示微液滴以溶剂的快速挥发为驱动力定向运输至交汇区的工作机制和动力学模型；探讨补丁交汇区提高电极品质的材料学机制；以智能应用为切入点，基于导电聚合物的智能特性，研究补丁的电极响应电信号的智能开关行为特性和机制，为构建高品质AgNW柔性透明电极及柔性电子的智能应用提供新思路和理论依据。

在寻求适用于柔性电子的氧化铟锡替代者中，基于银纳米线(AgNW)的柔性透明电极最具有应用前景。本项目针对AgNW柔性透明电极交汇区的接触电阻高且不稳定，导致电/光学和电/力学品质低下而无法在高端柔性电子中应用的问题，受蛛丝定向集水涉及浸润性差异和液滴无源自运输的启发，提出在AgNW交汇区定向引入补丁。研究表明，通过AgNW与柔性基材的表面能差与补丁液媒介的不对称快速挥发的协同作用，在紫外光照射下，触发定向迁移至交汇处的补丁液微液滴聚合形成聚吡咯(PPy)基补丁。补丁通过柔性导电串联的形式，显著降低和稳定接触电阻，实现提高电/光学和电/力学品质。基于PPy的智能开关特性，补丁的AgNW柔性透明电极被赋予响应周期性电信号的智能开关行为能力，并可集成于柔性电子器件及智能应用。该仿生定向补丁方法不仅针对AgNW柔性透明电极，也被证实适用于其他基于一维纳米材料(1DNM)的柔性透明电极，如铜纳米线柔性透明电极和碳纳米管柔性透明电极。本研究为构建高品质1DNM柔性透明电极奠定了材料基础，为1DNM柔性透明电极在可穿戴电子设备、柔性显示器和薄膜太阳能电池等柔性电子的智能应用提供了新思路和理论依据。