Highly stable silver nanowire networks with tin oxide shells for freestanding transparent conductive nanomembranes through all-solution processes

Freestanding nanomembranes (NMs) with nanoscale thickness, are mechanically flexible, which are novel building blocks with potential applications in future wearable conformal electronics. Here, we demonstrate a highly stable, ultrathin, freestanding, transparent, and conductive hybrid NM, consisting of a silver nanowire network with tin oxide shell embedded in a colorless polyimide (cPI). The entire fabrication processes are all solution based and non-vacuum, which are simple, scalable and low-cost, enabling facile large-area integration with wearable electronic devices. Our hybrid NMs possess high optical transmittance of 86.7% with low sheet resistance of 9.6 Omega/sq. and can be conformal attached to human skin. In addition, our hybrid NMs exhibit excellent stability to resist moisture, long-term storage, solvent damage, strong oxidant, ultrasonication and acid/base should stem. Particularly, the hybrid NMs are robust and able to withstand high temperature of 300 degrees C, without deterioration of performance. As a conformal/skin-attachable device application, a skin-attachable capacitive NM sensor is presented, which provides excellent pressure sensing capabilities.