title: Voltage-induced spreading and superspreading of liquids.
abstract: The ability to quickly spread a liquid across a surface and form a film is fundamental for a diverse range of technological processes, including printing, painting and spraying. Here we show that liquid dielectrophoresis or electrowetting can produce wetting on normally non-wetting surfaces, without needing modification of the surface topography or chemistry. Additionally, superspreading can be achieved without needing surfactants in the liquid. Here we use a modified Hoffman-de Gennes law to predict three distinct spreading regimes: exponential approach to an equilibrium shape, spreading to complete wetting obeying a Tanner's law-type relationship and superspreading towards a complete wetting film. We demonstrate quantitative experimental agreement with these predictions using dielectrophoresis-induced spreading of stripes of 1,2 propylene glycol. Our findings show how the rate of spreading of a partial wetting system can be controlled using uniform and non-uniform electric fields and how to induce more rapid superspreading using voltage control.
authors.affiliation: Department of Physics & Electrical Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, UK.
authors.forename: G
authors.initials: G
authors.lastname: McHale
authors.forename: C V
authors.initials: CV
authors.lastname: Brown
authors.forename: N
authors.initials: N
authors.lastname: Sampara