网格化固-液复合自愈合柔性透明电极及其制造技术研究

Flexible transparent electrodes with self-healing ability are of great significance for the development of a new generation of flexible optoelectronic devices with higher stability and stronger environmental adaptability. However, it is challenge to develop the flexible transparent electrodes with good conductivity, high transparency and the autonomous electrical self-healing ability simultaneously. This project proposes an innovative self-healing flexible transparent electrode with biphasic solid-liquid conductive grids. By applying an external electric field, the liquid metals are fully filled into imprinted grids which have been pre-filled with porous carbon nanotubes, achieving biphasic solid-liquid conductive grids with the liquid metals are fully infiltrated into the porous carbon nanotube conductive networks. The rapid electrical restorative mechanism of the self-healing flexible transparent electrodes under various deformations relies on the rheological filling of liquid metals into the pores or cracks of carbon nanotube conductive networks. By controlling the size of the biphasic solid-liquid conductive grids, the conductivity and transparency can be agilely adjusted to realize flexible transparent electrodes with good conductivity, high transparency, and autonomous electrical self-healing ability. This project will explore the basic theory in three aspects, including the mechanism of electro-wetting induced filling of liquid metals, the autonomous electrical self-healing mechanism of the biphasic solid-liquid conductive materials, and the influence of the characteristic parameters of biphasic solid-liquid conductive grids on the performance of the flexible transparent electrodes, aiming to provide a novel technique for the structural design and efficient manufacturing of the self-healing flexible transparent electrodes.

具有自愈合能力的柔性透明电极对于开发新一代稳定性更高、环境适应性更强的柔性光电器件具有重要意义，然而实现具有无延迟自愈合能力并兼具高导电性和高透光率的柔性透明电极是极具挑战的难题。本项目提出一种创新的网格化固-液复合自愈合柔性透明电极结构及制造方法，使用电场驱动液态金属向预先填有多孔碳纳米管的网格结构内完形填充，从而实现液态金属充分浸润碳纳米管导电网格的固-液复合柔性透明电极结构制造；利用固-液复合导电结构中液态金属向碳纳米管导电网络裂缝内的实时填充实现多种变形下电极裂纹的无延迟自主修复，通过控制导电网格的结构尺寸能够灵活调控导电性和透光率，实现兼具高导电性、高透光率和无延迟自愈合能力的柔性透明电极。本项目将在液态金属的电润湿填充规律、固-液复合导电结构的无延迟自愈合机理、网格结构参数对柔性透明电极性能影响规律等方面探索基础理论，为高性能自愈合柔性透明电极的结构设计和高效制造提供原创技术。

为了解决柔性透明电极在多种变形下电极裂纹的无延迟自主修复难题，本项目提出网格化固-液复合自愈合柔性透明电极的创新结构形式，开发了界面润湿驱动的网格化电路制造技术，形成了高导电、无延迟自愈合电路自主修复技术。项目揭示了电场作用下液态金属的润湿特性调控规律，分析电压幅值、频率以及波形对接触角大小的影响机制，开发界面润湿驱动的液态金属刮涂填充工艺；研究了固-液复合两相导电结构在拉伸等变形裂纹演变形貌，揭示了固态合金导电网络动态变形过程中液态金属向其内部裂纹中的填充自愈合机制、液-固界面共存特性，实现固-液复合两相导电结构的自愈合性能优化；开发了基于酰胺键的自愈合柔性聚合物，设计制造了液-固两相网格化柔性电路，实现了柔性电路机械性能和电学性能的自愈合，实现了透明电极网格结构的设计形式、特征尺度、排布方式的优化。此外，利用应变调制的裂纹敏感结构开发了柔性应变、振动传感器、高灵敏滑觉传感器。本项目在固-液复合导电结构的无延迟自愈合机理、裂纹结构动态演变规律、液态金属界面润湿填充规律等方面的研究成果，为自愈合柔性电路在柔性穿戴电子系统方面的应用提供了技术支撑。