Engineering the geometry of stripe-patterned surfaces toward efficient wettability switching

• Lattice Boltzmann simulations are performed on striped surfaces.
• Hysteretic transitions between suspended and collapsed states are demonstrated.
• We determine energy barriers separating co-existing stable wetting states.
• Energy barriers dependence on various surface geometric features is quantified.
• We present design directions for patterned surfaces with specific wettabilities.

The ability to control wettability is important for a wide range of technological applications in which precise microfluidic handling is required. It is known that predesigned roughness at a micro- or nano-scale enhances the wetting properties of solid materials giving rise to super-hydrophobic or super-hydrophilic behavior. In this work, we study the dependence of the apparent wettability of a stripe-patterned solid surface on the stripe geometry, utilizing systems level analysis and mesoscopic Lattice–Boltzmann (LB) simulations. Through the computation of both stable and unstable states we are able to determine the energy barriers separating distinct metastable wetting states that correspond to the well-known Cassie and Wenzel states. This way the energy cost for inducing certain wetting transitions is computed and its dependence on geometric features of the surface pattern is explored.

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