This shows ice accumulation on flat aluminum (A), smooth fluorinated Si (B), and microstructured fluorinated Si (C) surfaces. The advancing contact angle (CA) of the water droplets on these surfaces is indicated. Insets show micrographs of exemplary superhydrophobic surfaces: posts, bricks, blades, and honeycombs (scale bars: 10 μm). A stream of droplets (Tdroplet = 0 °C) was impinged from a 10 cm height at a rate of 0.06 mL/sec onto the surfaces (Tsubstrate = −10 °C) tilted at 30°. White dashed circles indicate the position of droplet impact. Ice accumulation was observed on both hydrophilic and hydrophobic surfaces, while no freezing or accumulation was observed on the superhydrophobic surface even after a significant period of time.