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Competing Bifurcations Determine Symmetry Breaking During Droplet Snaps on Smooth Patterned Surfaces
Lucile Bisquert1, Élfego Ruiz-Gutiérrez2, Marc Pradas3
1Institute for Multiscale Thermofluids, School of Engineering, University of Edinburgh, The King's Buildings Mayfield Road, Edinburgh EH9 3FB, United Kingdom.
Langmuir : the ACS Journal of Surfaces and Colloids
|November 6, 2024
Summary
Droplet behavior on patterned surfaces depends on size changes. The likelihood of symmetric or asymmetric shape changes (snaps) is determined by bifurcation points and their variation with droplet size.
Area of Science:
- Physics
- Materials Science
- Fluid Dynamics
Background:
- Droplet shape and stability on solids depend on surface properties and droplet size.
- Droplets on patterned surfaces can undergo sudden shape and position changes (snaps) during size variations like evaporation.
- These snaps are linked to fold (symmetric) and pitchfork (asymmetric) bifurcations, but predicting snap type is challenging.
Purpose of the Study:
- To determine the factors controlling symmetric versus asymmetric droplet snaps on smooth patterned surfaces.
- To understand the relationship between bifurcation points and snap behavior during droplet size changes.
- To provide insights for designing surfaces that manage droplet behavior.
Main Methods:
- Investigated droplet size variation effects on smooth patterned surfaces.
- Analyzed the influence of fold and pitchfork bifurcation distances on snap likelihood.
- Examined how these distances change as droplets grow or shrink.
Main Results:
- The probability of observing symmetric or asymmetric snaps is contingent upon the distance between fold and pitchfork bifurcation points.
- This likelihood is further influenced by how this distance evolves with changing droplet size (growth or shrinkage).
Conclusions:
- The study reveals that controlling the relative positions of bifurcation points on smooth patterns can dictate snap symmetry.
- These findings offer strategies for droplet manipulation using surface patterns.
- The principles extend to other systems exhibiting competing bifurcations and snap-through instabilities.
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