Using Vibrational Noise To Probe Energy Barriers Producing Contact Angle Hysteresis

We measure the macroscopic capillary rise height of water on a chemically heterogeneous solid surface in the presence of vibrational noise. The amount of relaxation of the macroscopic contact angle depends on the mechanical characteristics as well as the energy of the vibrations. The macroscopic recede and advance contact angles are functions of the vibration level. Large enough vibration levels mitigate hysteresis. Microscopic contact line configurations depend strongly on microscopic wettability variation on the solid surface. Our study has implications for contact angle measurements in normal vibration environments and for the retention of drops on inclined surfaces.