Thermodynamic analysis on an anisotropically superhydrophobic surface with a hierarchical structure

- We model the superhydrophobic surface with anisotropic and hierarchical structure.
- Anisotropic wetting only shows in noncomposite state (not in composite state).
- Transition from noncomposite to composite state on dual-scale structure is hard.
- Droplets tend to roll in the particular direction.
- Droplets tend to stably remain in one preferred thermodynamic state.