Light-Driven Transformation of Bio-Inspired Superhydrophobic Structure via Reconfigurable PAzoMA Microarrays: From Lotus Leaf to Rice Leaf

Light-driven transformation from isotropic superhydrophobicity to anisotropic superhydrophobicity was accomplished through bio-inspired modification and reconfiguration on poly[6-(4-methoxy-4′-oxyazobenzene)hexyl methacrylate] (PAzoMA) microarrays. In this study, ordered PAzoMA microarray film was fabricated via the reverse breath figure (RBF) method. After gold nanoparticles sputtering and subsequent modification with self-assembly of 1H,1H,2H,2H-perfluorodecanethiol (FSH), the obtained lotus-leaf-inspired film showed isotropic superhydrophobicity with self-cleaning property due to the hierarchical structure and low surface free energy. Upon irradiation with linearly polarized light (LPL), the microspheres were elongated along the direction of polarization and exhibited anisotropic superhydrophobicity resembling rice leaf. With the increase of illumination time, the axis ratio became larger, and anisotropy sliding was more obvious. This research enriches responsive bio-inspired superhydrophobicity and further provides a promising candidate for smart water harvesting.