Physics of Fluids - Publications

Soft electrowetting

arΧiv
Soft Matter 15, 6469–6475 (2019)

Authors

	Ranabir Dey
	Mathijs van Gorcum
	Frieder Mugele
	Jacco Snoeijer

BibTeΧ

@Article{C9SM00847K,
author ="Dey, Ranabir and van Gorcum, Mathijs and Mugele, Frieder and Snoeijer, Jacco H.",
title  ="Soft electrowetting",
journal  ="Soft Matter",
year  ="2019",
volume  ="15",
issue  ="32",
pages  ="6469-6475",
publisher  ="The Royal Society of Chemistry",
doi  ="10.1039/C9SM00847K",
url  ="http://dx.doi.org/10.1039/C9SM00847K",
abstract  ="Electrowetting is a commonly used tool to manipulate sessile drops on hydrophobic surfaces. By applying an external voltage over a liquid and a dielectric-coated surface{,} one achieves a reduction of the macroscopic contact angles for increasing voltage. The electrostatic forces all play out near the contact line{,} on a scale of the order of the thickness of the solid dielectric layer. Here we explore the case where the dielectric is a soft elastic layer{,} which deforms elastically under the effect of electrostatic and capillary forces. The wetting behaviour is quantified by measurements of the static and dynamic contact angles{,} complemented by confocal microscopy to reveal the elastic deformations. Even though the mechanics near the contact line is highly intricate{,} the macroscopic contact angles can be understood from global conservation laws in the spirit of Young–Lippmann. The key finding is that{,} while elasticity has no effect on the static electrowetting angle{,} the substrate{'}s viscoelasticity completely dictates the spreading dynamics of electrowetting."}