Preparations of versatile polytetrafluoroethylene superhydrophobic surfaces using the femtosecond laser technology

The accurate control of surface structure and wettability has important practical significance. In this study, a precise and controllable method was presented to fabricate versatile polytetrafluoroethylene (PTFE) superhydrophobic surfaces (SHs) with controllable wettability, low adhesion and anti-icing ability by femtosecond laser micromachining. The fabricated SHs exhibited excellent superhydrophobicity with contact angle (CA) of 166 degrees, rolling angle (RA) of similar to 2 degrees and low adhesion properties. The Cassie-Baxter model and formula were generalized according to the hydrophobic-superhydrophobic double wettability model we proposed, the numerical simulation results were in good agreement with experimental results. The controllable wettability could be achieved and tunable by designing and micromachining desired surface structure. The fabricated PTFE SHs demonstrated outstanding active anti-icing ability under extremely low-temperature conditions below -20 celcius. Such versatile characteristics of PTFE SHs are promising for applications in precise control of structure and wettability in different fields of anti-icing, anti-adhesion, bio-chips, anti-drag and other innovative fields.