Modified Inverted Layer Processing of Ultrathin Touch Sensor Impregnating Ag Nanowires with Both Enlarged Surface Coverage of Conductive Pathways and Ultralow Roughness

Abstract

Although previous studies have shown that Ag nanowire (AgNW) is among the most powerful means to replace the brittle indium tin oxide, physically flexible devices using AgNWs are not yet available on the market mainly because of the insufficient mechanical robustness of the AgNW-based electrodes. Here we propose a modified inverted layer processing (ILP) to fabricate mechanically robust, near-foldable transparent conductors by totally impregnating AgNWs just under the surface of cured polyvinyl butyral (PVB). A single demerit of the original ILP, low surface coverage of conductive pathways, was resolved by photo-induced heating of the AgNWs to settle them on a temporary substrate before coating and curing of the PVB. This resulted in wide coverage of conducting pathways on the surface of the AgNWs/PVB without compromising the ultralow surface roughness. Furthermore, the high strength and excellent compatibility of the PVB with the AgNWs facilitated the preparation of near-foldable touch sensors.