Magneto-responsive photothermal composite cilia for active anti-icing and de-icing

Ice buildup occurs through multiple routes of frost formation, condensate freezing, and supercooled raindrops. Therefore, it is crucial to integrate multiple anti- and de-icing functionalities in the design of next-generation ice-free materials. Herein, a multifunctional magneto-responsive photothermal composite cilia array (MRPA) exhibiting remarkable anti-icing and de-icing performance was demonstrated. The MRPA can exhibit an immediate and reversible structural actuating motion under an external magnetic field while maintaining superhydrophobicity regardless of the structural bending state. In addition, the MRPA has outstanding light absorption both in the ultraviolet–visible region (>98.3%) and the near-infrared region (>97.8%), and can thus efficiently convert solar energy into thermal energy. Accordingly, exceptional multifunctionalities including superhydrophobicity, controllable drop bouncing with reduced contact time and tunable rebound angle, on-demand active drop manipulation and removal, broadband light absorption, and efficient photothermal conversion could be realized in a single MRPA platform. Based on its multifunctional properties, the MRPA can inhibit, delay, and remove ice formation from both supercooled impinging and stationary droplets.