Anisotropic Contact-Angle Hysteresis of Chemically Nanostructured Surfaces

Abstract

Spatially alternating wetting properties are needed in order to test predictions on droplet contact angles on such complex, non-homogeneous surfaces. An evaporating droplet on a mica surface with hydrophillic strips 0.2–0.3 μm wide, as shown in the picture, recedes smoothly in directions parallel to the strips but in “jumps” with a variable contact angle perpendicular to the strips.