Manipulating Thin-Film Flows: From Patterned Substrates to Evaporating Systems
- Date: 03/10/2008
Howard A. Stone (Harvard University)
University of British Columbia
Here we describe two variants of thin-film flows, one involving wetting
and the other involving evaporation. First, we describe the spreading
of mostly wetting liquid droplets on surfaces decorated with assemblies
of micron-size cylindrical posts arranged in regular arrays. We obtain
a variety of deterministic final shapes of the spreading droplets,
including octagons, squares, hexagons and circles. Dynamic
considerations provide a “shape” diagram and suggest rules for control.
Second, we consider evaporation of volatile liquid drops. Using
experiments and theory we show how the sense of the internal
circulation depends on the ratio of the liquid and substrate
conductivities and how it controls the deposition patterns.
IAM - PIMS - MITACS
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