低温下曲挠应力对聚酰亚胺基银纳米线复合柔性电路的微观结构及电学性能的影响

Flexible electrical devices are highly desired in modern electrical systems. As the aerospace industry, high energy physics and biomedical science develop rapidly, flexible electrical systems that can stand for cryogenic environment attract more and more attention. The recently developed flexible electronics based on silver nanowire (Ag-NW) conducting networks have outstanding electrical properties and excellent anti-bending ability, showing that they are the promising candidates for fabricating high performance flexible electronic systems. However, the physical properties at cryogenic temperatures of the Ag-NW based electronics have been rarely investigated yet. In this proposal, polyimide (PI) based Ag-NW flexible electrical circuits are chosen as testing samples to investigate the influence of the bending stress on the micro-structure and the electrical property of the Ag-NW networks at cryogenic temperature. The main tasks include: 1) the fabrication of Ag-NW/PI flexible electrical circuit; 2) the design and manufacturing of the cryogenic bending test system; 3) the influence of the bending stress value and bending times on the micro-structure of the Ag-NW networks at cryogenic temperature; 4) the influence of the bending stress value and bending times on the electrical property of the Ag-NW flexible circuits at cryogenic temperature. Through this proposed research work, the influencing mechanism of bending stress on properties of Ag-NW electronics at cryogenic temperature will be explored, which can form a solid base for the design and manufacturing of high performance flexible cryogenic electrical devices.

现代电子系统的发展产生了对柔性电子器件的大量需求。随着航天、高能物理、生物医学等科技领域的发展，可应用在低温环境下的柔性电子系统日益受到关注。近期发展起来的基于银纳米线导电网络的柔性电子器件具有优异的电学性能和耐曲挠性能，是制造高性能柔性电子系统有效的解决方案。然而，关于银纳米线柔性电子器件在低温环境下的性能却鲜有研究。本项目拟选择聚酰亚胺基银纳米线柔性电路为研究对象，主要研究在低温环境下曲挠应力对银纳米线导电网络微观结构及电学性能的影响。其主要研究内容包括：1）聚酰亚胺基银纳米线柔性电路的制备；2）低温曲挠性能测试实验装置的设计和加工；3）低温下曲挠应力的大小和次数对银纳米线导电网络微观结构的影响；4）低温下曲挠应力的大小和次数对银纳米线柔性电路电性能的影响。通过此项目的研究，将得到低温下曲挠作用对柔性纳米电子器件的系统影响机理和规律，从而为制造高性能的低温柔性电子器件提供参考和依据。

柔性电子器件对于现代电子领域的发展具有重要的意义。近年来，随着空间探测、生物医学、高能物理等科技领域的发展，产生了对可应用在低温环境下的柔性电子器件的需求。银纳米线导电网络的柔性电子器件是近期发展起来的新型纳米复合材料导电器件，具有优异的电学和力学性能。但银纳米线柔性电子器件在低温环境下的性能却仍仍然缺失。本项目选择了聚酰亚胺基银纳米线柔性电路为研究对象，主要研究在低温环境下曲挠应力对银纳米线导电网络微观结构及电学性能的影响。首先通过新颖的两步法制备出了具有大长径比的银纳米线，再利用分步流延法制备出了聚酰亚胺包埋银纳米线导电网络的柔性复合薄膜。对银纳米线的制备参数以及复合薄膜的 渗透阈值进行了优化，并对其微观结构和力学性能进行了表征。建立了适用于室温/低温（77K）下薄膜耐曲挠测试的实验装置，并利用此装置对复合薄膜的常温以及低温耐曲挠性能进行了系统的研究。具体研究了不同曲挠半径及曲挠次数对复合薄膜微观结构以及整体电学性能的影响规律，研究成果可为低温柔性导电复合薄膜的研究提供有效的参考，具有较强的实用意义。