Printable High-Aspect Ratio and High-Resolution Cu Grid Flexible Transparent Conductive Film with Figure of Merit over 80 000

Figure of merit (FOM), the ratio of electrical conductance to optical transparency, is an important metric to evaluate transparent conductive film (TCF). The conductivity of commonly used flexible TCF such as indium tin oxide is generally limited and their FOM is lower than 300. In this study, a high-performance copper (Cu) metal-mesh TCF with the highest FOM ever reported, up to 8 x 10(4), is fabricated through an additive manufacturing process of blading a silver seed layer and selective electroplating of Cu. With this strategy, Cu metallic lines completely constrained in roll-to-roll imprinted microgrooves achieve high aspect ratio of 2 with 4 mu m width and 8 mu m depth, which has very clean and smooth edges. This embedded Cu metal mesh exhibits an ultralow sheet resistance down to 0.03 (-1) at 86% optical transmittance. It is demonstrated that the Cu metal mesh has remarkable mechanical flexibility, high environmental stability at high temperature and humidity, and durability over repeated heating cycles. The Cu metal mesh is employed as a flexible transparent heater to attach to the windshield of a car, showing rapid heating at low voltage and effective removal of snow.