Biomimetic Superhydrophobic Surfaces: Multiscale Approach

Published

September 26, 2007

Author(s)

Michael Nosonovsky

Abstract

Micro- and macro-droplet evaporation and condensation upon micropatterned superhydrophobic surfaces built of flattop pillars are investigated with the use of Environmental Scanning Electron Microscope. It is shown that the contact angle hysteresis depends upon both kinetic effects at the triple line and adhesion hysteresis (inherently present even at a smooth surface) and that the magnitude of the two contributions is comparable. The transition between the composite (Cassie) and wetted (Wenzel) states is a linear effect with the microdroplet radius proportional to the pitch over pillar diameter. It is shown that wetting of a superhydrophobic surface is a multiscale phenomenon with involves three scale lengths. Although the contact angle is the macroscale parameter, the contact angle hysteresis and the Cassie-Wenzel transition cannot be determined from the macroscale equations and are governed by micro- and nanoscale effects.

Citation

Nano Letters

Volume

7

Issue

9

Pub Type

Journals

Keywords

contact angle, superhydrophobic surfaces

Citation

Nosonovsky, M. (2007), Biomimetic Superhydrophobic Surfaces: Multiscale Approach, Nano Letters (Accessed November 30, 2023)