Near Axisymmetric Partial Wetting Using Interface-Localized Liquid Dielectrophoresis

Brabcova, Zuzana, McHale, Glen, Wells, Gary, Brown, Carl, Newton, Michael and Edwards, Andrew (2017) Near Axisymmetric Partial Wetting Using Interface-Localized Liquid Dielectrophoresis. Langmuir, 32 (42). pp. 10844-10850. ISSN 0743-7463

[img]
Preview
Text
Langmuir.pdf - Published Version
Available under License Creative Commons Attribution 4.0.

Download (3MB) | Preview
Official URL: http://dx.doi.org/10.1021/acs.langmuir.6b03010

Abstract

The wetting of solid surfaces can be modified by altering the surface free energy balance between the solid, liquid, and vapor phases. Liquid dielectrophoresis (L-DEP) can produce wetting on normally nonwetting surfaces, without modification of the surface topography or chemistry. L-DEP is a bulk force acting on the dipoles of a dielectric liquid and is not normally considered to be a localized effect acting at the interface between the liquid and a solid or other fluid. However, if this force is induced by a nonuniform electric field across a solid–liquid interface, it can be used to enhance and control the wetting of a dielectric liquid. Recently, it was reported theoretically and experimentally that this approach can cause a droplet of oil to spread along parallel interdigitated electrodes thus forming a stripe of liquid. Here we show that by using spiral-shaped electrodes actuated with four 90° successive phase-shifted signals, a near axisymmetric spreading of droplets can be achieved. Experimental observations show that the induced wetting can achieve film formation, an effect not possible with electrowetting. We show that the spreading is reversible thus enabling a wide range of partial wetting droplet states to be achieved in a controllable manner. Furthermore, we find that the cosine of the contact angle has a quadratic dependence on applied voltage during spreading and deduce a scaling law for the dependence of the strength of the effect on the electrode size.

Item Type: Article
Subjects: F200 Materials Science
Department: Faculties > Engineering and Environment > Physics and Electrical Engineering
Depositing User: Becky Skoyles
Date Deposited: 03 Oct 2016 15:54
Last Modified: 08 Sep 2017 06:10
URI: http://nrl.northumbria.ac.uk/id/eprint/27901

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics


Policies: NRL Policies | NRL University Deposit Policy | NRL Deposit Licence