Elongation of water drops in oil during transient electric fields

A water drop will elongate in an electric field due to the electrostatic pressure. From the drop deformation it is possible to derive the surface tension of the water drop. We have developed a method to study the rheological properties of a water droplet suspended in oil. By applying different voltage waveforms we can study transient and time varying effects, such as surface elasticity and time constants of adsorption of polar surfactants.