Wettability of a Vibrating Surface

A water droplet in contact with a solid surface gets an equilibrium shape that depends on its wettability, that is, the interaction between the three interfaces involved; solid-liquid, liquid-vapor and solid-vapor. We have found that if the surface vibrates vertically, the water droplet increases its wettability on the solid surface. In other words, the droplet changes its equilibrium shape keeping its constant volume. In this research, we have studied the wettability behavior of a droplet on a vibrating surface. We have recorded the time evolution of the radius and contact angle of a water droplet. Using imaging analysis, we establish the dynamical behavior of the droplet on the vibrating surface. For this task, we have as input variables the vibrating amplitude, the vibration frequency and the droplet volume. The images have been collected with a high-speed camera. Experimental results show that the spreading of the droplet increases as increase as of surface vibrating amplitude. We think this is due to a positive balance of the capillary force between the successive expansions and contractions of the water drop.