Pinning and wicking in regular pillar arrays

Ciro Semprebon, Pontus Forsberg, Craig Priest, Martin Brinkmann

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)

Abstract

Pinning and wicking of a liquid meniscus in a square array of pillars is investigated in numerical energy minimizations and compared to wetting experiments. Our combined study shows that criteria for spontaneous film formation, based on thermodynamic considerations as well as on simple geometric modelling of the meniscus shape, are insufficient to predict the onset of wicking. High aspect ratio pillars with a square cross-section may display a re-entrant pinning regime as the density of the pillars is increased, a behaviour that is captured by neither of the aforementioned models. Numerically computed energy landscapes for the advancing meniscus allow us to explain the re-entrant behaviour in terms of energy barriers between topologically different meniscus shapes. Our numerical results are validated by wicking experiments where for the material contact angle θ0 = 47° the re-entrant behaviour is present for square pillars and absent for pillars with circular cross section.

Original languageEnglish
Pages (from-to)5739-5748
Number of pages10
JournalSoft Matter
Volume10
Issue number31
Early online date16 May 2014
DOIs
Publication statusPublished - 21 Aug 2014

Fingerprint Dive into the research topics of 'Pinning and wicking in regular pillar arrays'. Together they form a unique fingerprint.

Cite this