Dynamical superhydrophobicity

Superhydrophobicity is mainly remarkable for the special dynamical behaviours it generates: low adhesion, giant hydrodynamic slip, frictionless motion, rebounds after impacts. Here we discuss most of these properties. We first recall how contact angle hysteresis can be minimized in this state. Then, we show that a water drop first follows the Galilean law of free fall on an incline, before reaching a stationary state, for which we discuss the associated friction. Finally, the property of water repellency (that is, rebounds after impact) is presented. We describe in particular how the texture responsible for superhydrophobicity can also influence the figure of impact at a very large scale.