Ultrahydrophobicity
（重定向自Superhydrophobicity）
Ultrahydrophobic (or Superhydrophobic) surfaces are highly hydrophobic, i.e., extremely difficult to wet. The contact angles of a water droplet exceeds 150° and the roll-off angle/contact angle hysteresis is less than 10°. This is also referred to as the Lotus effect, after the superhydrophobic leaves of the lotus plant. A droplet impacting on these kind of surfaces can fully rebound like an elastic ball, or pancake.