Surface wettability is a critical factor influencing the biological performance of orthopedic Ti implants. The native TiO₂ film on Ti undergoes changes in wettability under ultraviolet (UV) irradiation. However, the limited tissue penetration of UV light compared with near-infrared (NIR) light restricts its potential clinical application. In this study, a black TiO₂ (b-TiO₂) coating with NIR-responsive wettability was fabricated directly on a Ti substrate using a one-step atmospheric plasma spraying process. Under 808 nm NIR irradiation, the water contact angle of the b-TiO₂ coating increased from 0° to 154.4 ± 4.0°, indicating a transition from a superhydrophilic to a stable superhydrophobic state. FTIR and XPS analyses showed that NIR-induced photothermal heating promoted the removal of surface hydroxyl groups and the passivation of oxygen-deficient sites, thereby driving the wettability transition. Among TiO₂ coatings with hydrophilic, intermediate-wettability, and hydrophobic surfaces, the hydrophobic coating effectively directed macrophage polarization toward the anti-inflammatory M2 phenotype and delivered slightly superior osteoblast activity. It also markedly inhibited Staphylococcus aureus adhesion, achieving an anti-adhesion efficiency of 98.61%. These findings demonstrate that NIR irradiation can regulate the wettability of plasma-sprayed b-TiO₂ coatings and provide concurrent immunomodulatory and antibacterial effects. This approach may support the development of light-responsive surfaces for orthopedic implants.

As the number of etching cycles continues to increase, conventional yttrium oxide (Y₂O₃) coatings can no longer meet the rigorous demands of advanced−node etching machines. Yttrium oxyfluoride (YOF) exhibits a lower etching rate under fluorine radical erosion compared with Y₂O₃; incorporating YOF into Y₂O₃ coatings therefore provides an effective approach to mitigating plasma erosion. In this study, three types of yttrium−based spherical powders (Y₂O₃-YOF, YOF, and Y₅O₄F₇) were prepared by combining a solid-state reaction method with spray granulation. These were subsequently used to fabricate Y₂O₃-40vol.%YOF, Y₂O₃-60vol.%YOF, and pure YOF coatings via atmospheric plasma spraying (APS), with a pure Y₂O₃ coating serving as the control. CF₄/Ar plasma etching experiments revealed that the surface maximum local erosion depth and the changes in surface roughness (before and after etching) of all three YOF-containing coatings were lower than those of the pure Y₂O₃ coating. Notably, the Y₂O₃-40vol.%YOF coating, with its lower YOF doping level, exhibits the lowest value of maximum local erosion depth (59.3 nm) and minimal roughness variation among the tested samples. Although excessive YOF incorporation produced relatively high porosity, EDS and XPS analyses indicated that an optimal YOF doping level significantly suppresses the formation of new fluorinated products during etching. Overall, the Y₂O₃-40vol.%YOF coating demonstrates high structural stability against both chemical fluorination and physical impact, suggesting its suitability for application in next-generation etching equipment.