Scalable Fabrication of Rewritable, Switchable, and Stable Superhydrophilic-Superhydrophobic Titanium Micropatterns...

Nature-inspired surfaces with hybrid wettability hold significant promise for water harvesting, dropwise condensation, and biomedical liquid arrays. However, current fabrication methods are hampered by restricted pattern complexity, reliance on toxic fluorides, mask alignment inaccuracies, and poor scalability. Here, we introduce a fluorine- and mask-free, implant-grade process to create superhydrophilic-superhydrophobic (SHPi-SHPo) patterns on titanium via sequential laser machining, silicone oil heat treatment, and ultraviolet (UV) irradiation treatment. Through parametric optimization of laser parameters and UV exposure, we establish ideal fabrication conditions for achieving micron-scale accuracy, enhanced stability in SHPi micropatterns, and long-term durability of the SHPo substrate. The underlying mechanisms governing wettability transitions and stability were elucidated through surface morphology and surface chemistry analyses. Additionally, the SHPi regions within hybrid architectures exhibit switching between extreme wettability states (SHPi and SHPo) via UV irradiation and thermal annealing cycles while maintaining adjacent SHPo regions' integrity without cross-contamination. Moreover, additional silicone oil heat treatment fully erases prior patterns and enables micron-scale rewriting of arbitrary designs. This scalable, eco-friendly fabrication strategy opens new avenues for dynamic fluid management, efficient heat transfer, and reconfigurable biomedical interfaces.