Photothermal Superhydrophobic Coatings Based on Biomimetic Butterfly-Inspired Light-Trapping Structures

To address the safety hazards caused by ice accumulation in low-temperature environments, a bioinspired functional coating (SST-PF) was designed and fabricated with integrated photothermal conversion and superhydrophobic properties, aiming to achieve efficient and energy-saving anti-/de-icing performance. The surface micro/nanostructure of Kaniska canace butterfly wings was selected as a bioinspired light-trapping template, and its simplified morphology was reconstructed using Scanning Electron Microscopy (SEM) and UG-based geometric modeling. A reverse-structure mold was created through 3D printing, followed by casting of a PDMS/Fe 3 O 4 composite to form a photothermal substrate. Subsequently, SiO 2 nanoparticles were sprayed onto the surface to construct a dual-scale roughness, imparting excellent superhydrophobicity. Wettability tests revealed that SST-PF exhibited a water contact angle of [Formula: see text] and a sliding angle of [Formula: see text]. Under simulated solar irradiation ([Formula: see text]), the surface temperature rose to [Formula: see text] within 240[Formula: see text]s, significantly accelerating droplet evaporation. In subzero conditions ([Formula: see text]), the coating extended the freezing time of water droplets to 530[Formula: see text]s and markedly delayed frost formation under illumination. At ambient temperature, under a simulated solar illumination of [Formula: see text], a 4[Formula: see text]mm-thick ice layer could be completely melted and detached within 180[Formula: see text]s. Beyond photothermal de-icing, mechanical de-icing was quantified with a push–pull method: the ice adhesion strength of SST-PF is 7.9[Formula: see text]kPa[Formula: see text]2.1[Formula: see text]kPa, substantially lower than ST-PF (57.6[Formula: see text]kPa[Formula: see text]6.5[Formula: see text]kPa) and PF (145.1[Formula: see text]kPa[Formula: see text]14.7[Formula: see text]kPa). Self-cleaning was verified in two modes–water-assisted rinsing and wind-driven removal at 5[Formula: see text]m/s–both restoring a clean surface. Durability tests show negligible WCA loss under repeated water-drop impact and sand abrasion, excellent acid stability (1[Formula: see text]mol/L HCl) but a gradual WCA decline in base (0.995[Formula: see text]mol/L NaOH), and preserved superhydrophobicity after six thermal cycles between [Formula: see text] and [Formula: see text]. Under blade scratching, SST-PF maintains a WCA of approximately [Formula: see text] and an unchanged photothermal response, demonstrating robustness. Overall, the light-trapping superhydrophobic architecture delivers rapid, low-energy de-icing with strong robustness against mechanical, chemical and thermal stresses, supporting practical deployment in cold environments.