基于织物表面的可印刷弹性导电浆料的制备及其拉伸导电机制研究

Currently wearable devices is a hot research topic in the field of information and communication technology, and among these existing wearable devices, smart textiles will be the future development direction. However, the interconnection printed wires between electronic devices integrated on fabrics can’t be deformed during the wearing process, which doesn’t have practical value. In this proposal, we aim to develop a stretchable silver nanowires (Ag NWs) conductive paste for low-voltage circuitry on textile substrates, which possesses excellent stretchability, adhesion, and conduction. We are going to focus the following contents: homogeneous mixing of Ag NWs conductive filler with elastic polymer, and study the relationship between different experimental parameters and tensile mechanical / electrical changes of conductive pastes; reveal the regulation mechanism of silver nanowires’ distribution with different structures in elastic paste, and understand the corresponding electrical changes under straining process; study the printing process on fabric surface and evaluate the wash and abrasion performance. The knowledge obtained through the above research would helpful to fabricate the conductive paste with elasticity, and eventually develop the break-through technique for interconnection wires between electronic devices integrated on fabrics, and develop the smart fabric with wearability.

可穿戴设备目前是信息通信技术研究的热点，其中智能纺织品将是其未来的发展方向。但是目前智能面料表面电子器件之间的印刷互联导线并不具有延展性，因此无法满足穿着服用性。本项目拟通过高长径比银纳米线和弹性树脂分别代替传统浆料中的金属颗粒导电填料及刚性树脂，制备一种新型的具有可延展特性的导电浆料，同时探讨其在纺织面料表面的印刷工艺。具体内容包括：解决银纳米线导电填料跟弹性聚合物的均匀混合，研究不同实验参数与导电浆料拉伸力学/电学变化之间的关系；揭示弹性浆料中银纳米线不同分布结构的调控机制，并且理解相应拉伸电学变化规律；实现面料表面印刷制备同时评价其服用性能。本项目旨在成功制备可印刷弹性浆料，并且实现面料表面弹性互联导线的制备，为研究具有真正服用性能的智能织物提供基础。

纺织面料由于其优异的柔韧性及透气吸水特性，越来越多的被选择为柔性电子器件的衬底材料，广泛应用于可穿戴电子领域，如何实现其表面可拉伸、耐揉搓电极电路的制备，是面料基柔性电子器件的基础。本项目从两个不同的角度研究了印刷柔性可拉伸电路的制备方法：（1）预先调配弹性导电浆料，然后通过丝网印刷实现可拉伸电极电路的制备；（2）预先构建Ag NWs导电网络，然后浇筑PDMS溶液，加热固化后形成Ag NWs/PDMS复合导电电极。本项目取得的成果如下：（1）完成可拉伸弹性浆料的配制，实现面料表面丝网印刷工艺优化，理解印刷电极烧结过程中溶剂挥发相分离机制及其对电学特性的影响，实现面料表面丝网印刷电极方块电阻为0.94 Ω/□，导电率达到8300 S/cm，50%拉伸幅度电阻增加仅为2.3倍。（2）基于金属网格可拉伸透明导电膜，开发出面料表面可拉伸、耐揉搓、可水洗电致发光器件。解决了柔性电致发光器件三个关键问题：（a）弹性透明导电膜的制备；（b）发光层弹性聚合物的筛选及印刷均匀性；（c）器件三层界面紧密贴合。（3）利用印刷的方法实现Ag NWs/ PDMS柔性可拉伸电路的制备，理解拉伸形变过程中电学变化规律，拉伸回缩过程中由于Ag NWs/PDMS复合弹性体无法回复到原始状态，因此在其下层纯PDMS回复带动下，复合电极表面出现规整的屈曲褶皱微结构，从而实现一定范围内拉伸电阻不变。（4）通过丝网印刷结合真空抽滤的方法实现Ag NWs导电网络的高分辨图形化，线径及线间距达到50μm。通过控制单位面积表面Ag NWs沉积量，实现对可拉伸电极不同电学性质的调控。实现了同一样品表面150个微电极电阻分布偏差仅有±0.61Ω，不同批次样品间微电极电阻也非常均匀。