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Updated: Apr 8, 2026

Taking Advantage of Reduced Droplet-surface Interaction to Optimize Transport of Bioanalytes in Digital Microfluidics
Published on: November 10, 2014
Capillary droplet propulsion on a fibre
Sabrina Haefner1, Oliver Bäumchen, Karin Jacobs
1Saarland University, Department of Experimental Physics, 66041 Saarbrücken, Germany. k.jacobs@physik.uni-saarland.de.
Abstract:
A viscous liquid film coating a fibre becomes unstable and decays into droplets due to the Rayleigh-Plateau instability (RPI). Here, we report on the generation of uniform droplets on a hydrophobized fibre by taking advantage of this effect. In the late stages of liquid column breakup, a three-phase contact line can be formed at one side of the droplet by spontaneous rupture of the thinning film. The resulting capillary imbalance leads to droplet propulsion along the fibre. We study the dynamics and the dewetting speed of the droplet as a function of molecular weight as well as temperature and compare to a force balance model based on purely viscous dissipation.
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