Switchable wettability control of titanium via facile nanosecond laser-based surface texturing

Abstract Control of surface wettability is very important and useful for many industrial applications, and can be realized by controlling surface chemistry and microstructure simultaneously. Here, we present a facile laser-based surface texturing method to achieve switchable wettability control on titanium surface. The experimental results indicate that the laser-treated surfaces became superhydrophilic immediately upon laser texturing. Using alternate low-temperature heat treatment and UV irradiation, the wettability of the laser-treated surface could be efficiently switched between superhydrophilicity and superhydrophobicity for many times. Surface morphology and chemistry analyses confirm that the reversible wettability transition should be attributed to the combined effect of the dual-scale surface structure and controllable surface chemistry. Using the laser-based wettability control method, a water collection device was fabricated and demonstrated by a superhydrophobic-superhydrophilic hybrid surface pattern. The developed method could enable a practical throughput for large-area processing, and endow various industrial applications.