Dresden 2014 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 18: Wetting, Superamphiophobicity, Micro- and Nanofluidics I

CPP 18.9: Talk

Tuesday, April 1, 2014, 11:45–12:00, ZEU 222

Wetting and electrowetting — Markus Bier and •Ingrid Ibagon — MPI for Intelligent Systems, Stuttgart, Germany

The phenomenon of electrowetting, i.e., the dependence of the macroscopic contact angle of a fluid on the electrostatic potential of the substrate, is analyzed in terms of the density functional theory of wetting. A comparison with the traditional scheme based on capacitor models reveals qualitative errors of the latter approach. Within density functional theory one accounts for the formation of a microscopically thin film which (partially) wets the substrate. By that means one obtains an improved expression for the electrowetting number as a function of the voltage. The improved theory is compared with available experimental results and with predictions of the traditional approach. An experimental setup is proposed to differentiate between the traditional and the density functional approach to electrowetting.