Precise controllable self-healing composite coating towards designated corrosion locations

Self-healing properties are widely incorporated into anti-corrosion coatings to improve their durability and reliability. Yet, precisely targeting and controlling self-healing actions for designated microdefects and early corrosion pits continue to pose substantial challenges. Herein, a precise controllable self-healing anticorrosion composite coating is realized by combining layer-specific nanofiber membranes and epoxy blockage layer, under stimulation of remote near-infrared (NIR) light. This coating demonstrates highly accurate positioning for corrosion sites, exhibiting conspicuous fluorescence signals by chelating with corrosion-released metal ions. Subsequently, precise regional control of self-healing behaviors in designated locations is achieved within 30 s, with a self-healing anticorrosion efficiency of 96.32 %. It also sustains fast yet precise healing abilities under varied harsh conditions, including underwater, simulated seawater, ultra-low temperatures, and even vacuum environments. The universally precise self-healing tactic makes composite coating extensively available for a range of scenarios and offers a valuable inspiration for developing in-situ self-healing systems with high precision.