Highly flexible and transparent film heaters based on polyimide films embedded with silver nanowires

Abstract

Highly flexible and transparent film heaters (TFHs) with superior mechanical and thermal stability were fabricated by embedding silver nanowires (AgNWs) into transparent polyimide (PI) films using a solution coating method. The fabricated AgNW/PI hybrid TFHs exhibited higher heating temperatures (∼96 °C) with lower input voltage (∼6 V), shorter response time (T < 40 s), and lower power consumption (160.6 °C cm² W⁻¹) than ITO/FTO heaters, as well as stability after repeated use. The AgNW/PI hybrid TFHs also showed excellent resistance to bending. After undergoing outer bending for a 1000 times, the change of sheet resistance was less than 18%. The effective embedment of the AgNW network in the surface of the transparent PI film not only decreased the surface roughness (R_rms < 1 nm) but also enhanced the resistance against oxidation and moisture. Potential applications of the AgNW/PI TFHs in window defogging and thermochromics are demonstrated.