Extreme liquid repellency or superhydrophobicity can be achieved by texturing hydrophobic material at the micro-and nano-scale, which can trap an air cushion beneath a water droplet. As a result, the water droplet beads up into an almost perfect sphere with a static contact angle θ > 150 • . The droplet also experiences minimal contact-line pinning and can move across the superhydrophobic surface with little friction. This lack of pinning or friction can be quantified by the contact angle hysteresis ∆θ = θ a -θ r (< 10 • for most superhydrophobic surfaces) or more specifically its cosine form ∆ cos θ = cos θ r -cos θ a , where θ a and θ r are the advancing and receding contact angles, respectively. Another defining characteristic of superhydrophobic surfaces is the ability of water droplets to rebound (sometimes multiple times) following impact, which is key to many potential applications such as water-proofing, anti-repellent and anti-icing coatings, as well as for optimizing heat transfer. The energy loss for the rebounding droplet can be quantified by the restitution coefficient e = U R /U I where U R and U I are the rebound and impact speeds, respectively. Different groups have independently reported the non-monotonic dependence of e with impact speed U I . Initially, there is no rebound (e = 0) until U I exceeds a critical speed U crit . Once U I > U crit , e increases sharply from 0 up to a maximum value of about 0.9 before it starts to decrease gradually with increasing U I .