Monostable superrepellent materials

Significance Existence of monostable Cassie states is exhibited using simple pillars exposed to mercury and dual-length-scale structures exposed to water, respectively. Then, transitions from the Cassie state to the Wenzel state are repaired without energy input, which prevents the often-reported irreversible breakdowns of superhydrophobicity. Constructing a phase diagram where both the texture density and the surface chemistry are varied allows us to establish the conditions of monostability. Furthermore, the region in the phase diagram where monostable Cassie states are observed is found to be large enough to guide further design and engineering of robust superrepellent materials.