Electric-field-induced oscillations of water droplets deposited on insulating surfaces

The 3-D oscillations of a water droplet under the effect of external fields, such as gravity and sinusoidal electric field, were investigated numerically. The time variation of the shape of a perfectly conducting droplet demonstrates that a water droplet vibrates strongly at certain frequencies. It was found that the resonance frequency and the magnitude of the deformation strongly depend on the surface properties and the value of contact angle. A comparison of the numerical results with the known experimental data shows satisfactory agreement with respect to the shape of the droplet and the resonant frequencies.