Highly flexible transparent conductors based on 2D silver nanowire network

Abstract

Electronic devices that can be flexed, rolled or folded allow integration of conventionally stiff electronic devices to arbitrary surfaces, such as the curved and elastic human body and its tissues, enabling next-generation bio-electronic devices. Using randomly arranged networks of silver nanowires, ∼ 50 µm long, we fabricated and characterized foldable transparent conductors. Silver nanowires are investigated as they exhibit superior electrical, optical and mechanical properties. We examine the change in the percolation network of the silver nanowire films at small bending radii. The electrical resistance is found to increase as the bending radius is decreased. Loss of contact between nanowires at the junctions and poor adhesion to the substrates contribute to an increase in electrical resistance. We propose a simple method to circumvent these problems. By applying a thin layer of conductive polymer, poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), onto the silver nanowire film, we are able to demonstrate a transparent conductor that maintains good electrical conductivity even upon bending to a very small bending radius (< 1 mm) without deterioration of the electrical properties.