Kang Yu, Wang Guoqi, Zhao Sanchuan, Li Jiaye, Di Lu, Feng Yang, Yin Jun, Zhu Jian
School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin, 300350, P. R. China.
Tianjin Key Laboratory for Rare Earth Materials and Applications, Nankai University, Tianjin, 300350, P. R. China.
Small. 2020 Dec;16(50):e2004793. doi: 10.1002/smll.202004793. Epub 2020 Nov 23.
Stretchable conductors capable of precise micropatterning are imperative for applications in various wearable technologies. Metallic nanoparticles with low aspect ratios and miniscule sizes are preferred over metallic nanowires or nanoflakes for such applications. However, nanoparticles tend to lose mutual contact during stretching. Therefore, they are rarely used alone in stretchable conductors. In this study, electronic inks comprising silver nanoparticles (AgNPs) for the high-resolution printing of stretchable conductors are reported. AgNPs are synthesized using aqueous polyurethane micelles, which are subsequently disentangled into polymeric chains in isopropanol to stabilize the inks. The ink rheology can be arbitrarily tuned to allow direct-write printing with a minimum feature width of 3 µm. Owing to the absence of extra surfactants, direct drying of such inks at room temperature provides the stretchable conductors with an initial conductivity of 8846 S cm and conductivity of 1305 S cm at 100% strain. This enhanced performance is attributed to the conductive percolations through assemblies of AgNPs adapting to the strain and is equivalent to those of stretchable conductors filled with Ag nanowires or flakes. These inks are promising for the scalable fabrication of highly integrated stretchable electronics.
对于各种可穿戴技术应用而言，能够进行精确微图案化的可拉伸导体至关重要。在此类应用中，低纵横比和微小尺寸的金属纳米颗粒优于金属纳米线或纳米薄片。然而，纳米颗粒在拉伸过程中往往会失去相互接触。因此，它们很少单独用于可拉伸导体中。在本研究中，报道了用于可拉伸导体高分辨率印刷的包含银纳米颗粒（AgNP）的电子墨水。AgNP是使用水性聚氨酯胶束合成的，随后在异丙醇中解缠为聚合物链以稳定墨水。可以任意调节墨水流变学特性，以实现最小特征宽度为3 µm的直写印刷。由于不存在额外的表面活性剂，此类墨水在室温下直接干燥可使可拉伸导体的初始电导率达到8846 S/cm，在100%应变下的电导率为1305 S/cm。这种增强的性能归因于通过适应应变的AgNP组件的导电渗滤，并且等同于填充有Ag纳米线或薄片的可拉伸导体的性能。这些墨水对于高度集成的可拉伸电子产品的可扩展制造具有前景。
