3D stretchable and transparent conductors with controllable strain-distribution based on template-assisted transfer printing

摘要： Although stretchable transparent conductors, stemmed from the strategies of both conductive composite and structural design of non-stretchable conductors, have been extensively studied, these conductors either suffer from a low stretchability or require a complex fabrication process, which drastically limits their practical applications. Here, we propose a novel strategy combining the design of substrates and a simple template-assisted transfer printing process to fabricate 3D transparent conductors. The strategy not only eliminates the complex and costly fabrication processes, but it also endows conductors with high stretchability and long-term stability thanks to the controllable strain-distribution as well as the seamless connection between the conductor layer and the substrate. These newly-designed 3D conductors achieve a low sheet resistance of 1.0 Ω/sq with a high transmittance of above 85% and remain stable without obvious resistance change during 1000 stretching-relaxation cycles until 60% strain, which are superior to most reported conductors. A large-area stretchable heater based on the 3D conductor realizes the temperature fluctuation below 10% even under a large strain, thus showing huge application prospects in the field of wearable healthcare electronics. The simple solution-processed fabrication method and high performance such as stretchability and low resistance change over large strain range promote the practical applications of these newly-designed 3D conductors.