A hierarchical superaerophilic cone: Robust spontaneous and directional transport of gas bubbles

In this paper, we present a rapid and simple method to fabricate superaerophilic polytetrafluoroethylene cones via a two-step femtosecond laser direct writing technique, which enormously improved processing efficiency compared to the existing method. The laser-treated cones contained hierarchical microstructures and exhibited self-driven and directional transport of gas bubbles along the cones and away from the tip, even when the cones were horizontal. Furthermore, the laser-treated cones exhibited excellent chemical and long-term stability. This work may provide an effective and simple approach to obtain efficient manipulation of gas bubbles in practical applications.