Superspreading without surfactants: Dielectrowetting

When a droplet is put on a surface it spreads out, but how fast does it spread and how far can it spread?

A droplet of oil induced to wet a non-wetting substrate by an applied voltage.

Our experiments use a non-uniform electric field to create a force on the dipoles of a dielectric liquid.For droplets this forces them to set surfaces what we call “dielectrowetting”. This allows a voltage to be used to “dial up” the final state of a droplet. This can be a droplet, just sufficient to create a film or more than that needed to create a film. One does not need to wait for a film to form – the difference can be seen in how fast a droplet spreads.

Publications

  • Dielectrowetting driven spreading of droplets
    G. McHale, C.V. Brown, M.I. Newton, G.G. Wells and N. Sampara
    Physical Review Letters 107 (18) (2011) art. 186101.
  • Voltage induced superspreading
    C.V. Brown, G. McHale and N. Sampara
    Nature Communications 4 (2013) art. 1605.
    (for copy contact glen.mchale@northumbria.ac.uk)