Transparent Deformable Thin Film Electric Heater for Stable and Accurate Control of High Temperatures

ABSTRACT

Transparent and flexible heaters with high thermal stability are critical for a wide range of applications, including smart windows, haptic interfaces, wearable healthcare devices, and frost or condensation prevention in vehicles, as well as transportation systems operating in extreme environments. However, current transparent heater technologies—based on conductive oxides, carbon‐based materials, and metallic nanowires—suffer from intrinsic limitations such as brittleness, susceptibility to oxidation, high operating voltages, limited controllability of high temperature, and poor long‐term reliability. In this work, we introduce a printed amorphous gallium oxide (GaO _x ) film as a platform for transparent heaters. When trace amounts of Au are deposited on the film, the GaO _x layer facilitates spontaneous mutual diffusion, leading to the formation of an Au–Ga alloy. This alloy formation effectively suppresses electromigration and solid‐state dewetting of Au at high temperatures. As a result, the Au/GaO _x heater achieves low sheet resistances of 6–16 Ω/sq while maintaining high optical transmittance (69%–86%). Notably, the device demonstrates precise, repeatable temperature control and exceptional long‐term stability at unprecedented operating temperatures up to 521°C. Furthermore, the heater exhibits outstanding mechanical durability, retaining performance under severe crumpling deformation. This strategy establishes a versatile platform for high‐temperature transparent heaters, enabling both conventional and shape‐adaptive applications.