Vapor stabilizing substrates for superhydrophobicity and superslip

The success of rough substrates designed for superhydrophobicity and superslip relies crucially on the presence of air pockets in the roughness grooves. This air is supplied by the surrounding environment. However, if the rough substrates are used in enclosed configurations, such as in fluidic networks, the air pockets may not be sustained in the roughness grooves and may diffuse out. In this work, a design approach based on sustaining a vapor phase of the liquid in the roughness grooves, instead of relying on the presence of air, is explored. The resulting surfaces, referred to as vapor stabilizing substrates, are deemed to be more robust against wetting transition even if no air is present.