Wetting and friction on superoleophobic surfaces

This article describes the physics of superoleophobic surfaces, combining a recently developed free-energy approach and finite element modeling. We start by investigating the peculiar wetting behavior of such surfaces, originating in their re-entrant'' geometry, and discussing a specific mechanism for the filling transition'', leading to the loss of superoleophobicity. We then focus on their friction properties, and establish an important condition for their use as super-lubricating surfaces. This new insight into the underlying mechanisms of superoleophobicity enables us to suggest general principles to optimize the wetting and friction properties of those promising surfaces.