Different Roles of Surface Chemistry and Roughness of Laser-Induced Graphene: Implications for Tunable Wettability

The control of surface wettability is a technological key aspect and usually poses considerable challenges connected to high cost, nanostructure, durability, especially when aiming at patterning with extreme contrast. This work shows simple scalable approach by using laser-induced graphene (LIG) locally inert atmosphere continuously tune the polyimide/LIG from hydrophilic superhydrophobic (Φ ∼ 160°). related reduced amount oxygen on LIG surface, influenced local atmosphere. Furthermore, influence roughness pattern investigated. Both approaches are combined, chemistry discussed. Measurements roll-off angle show that scribed in an low has highest droplet mobility ΦRO = (1.7 ± 0.3)°. properties samples were maintained for over year showed no degradation after multiple uses. Applications surfaces contrast millifluidics fog basking demonstrated. Overall, proposed processing allows continuous tuning very accessible fashion useful “lab-on-chip” applications.