Realization of Highly Foldable Conductive Substrates with 2000 Cyclic Mechanical Stability through Silver Nanowires/Cellulose Structure Design

Foldable electronics, with the advantages of size compactness and shape transformation, are promising for portable and wearable applications. The challenge for realizing foldable devices is exploiting highly foldable conductive substrates free from deformation under large strain. In this work, highly foldable and degradable transparent conductive substrates were constructed using ∼20 μm ultrathin regenerated cellulose film (RCF) substrates to reduce strain, embedding silver nanowires (AgNWs) into RCFs to improve the interface binding force, as well as improving the adhesive strength of AgNWs junction. The AgNWs/RCF complex with an initial sheet resistance of 14 Ω/sq maintained an electrical conductivity after either single folding for 2000 cycles or double folding for 1000 cycles. Moreover, the difference in the electrical characteristics of AgNWs/RCF after single folding with +180 and −180° angles as well as double folding was explained to be related to the different microstructure deformations. Lastly, the first foldable polymer-dispersed liquid crystals devices using the AgNWs/RCF conductive substrates were demonstrated with 1400 cyclic stability. Our work paves the way toward realizing highly foldable transparent electrodes for foldable displays and detectors and wearable device applications.