Issue
EPL
Volume 83, Number 6, September 2008
Article Number 64002
Number of page(s) 5
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/83/64002
Published online 09 September 2008
EPL, 83 (2008) 64002
DOI: 10.1209/0295-5075/83/64002

Impalement transitions in droplets impacting microstructured superhydrophobic surfaces

J. Hyväluoma and J. Timonen

Department of Physics, University of Jyväskylä - FI-40014 Jyväskylä, Finland, EU

jari.hyvaluoma@jyu.fi

received 7 April 2008; accepted in final form 28 July 2008; published September 2008
published online 9 September 2008

Abstract
Liquid droplets impacting a superhydrophobic surface decorated with micron-scale posts often bounce off the surface. However, by decreasing the impact velocity, droplets may land on the surface in a fakir state, and by increasing it, posts may impale droplets that are then stuck on the surface. We use a two-phase lattice Boltzmann model to simulate droplet impact on superhydrophobic surfaces, and show that it may result in a fakir state also for reasonable high impact velocities. This happens more easily if the surface is made more hydrophobic or the post height is increased, thereby making the impaled state energetically less favourable.

PACS
47.55.dr - Interactions with surfaces.
47.55.D- - Drops and bubbles.
68.08.Bc - Wetting.

© EPLA 2008