Investigation of Upward Climbing Motion of a Droplet over an Inclined Surface Using Electrowetting

The motion of a water droplet under the electric actuation force is studied in detail to examine its directional motion along the surface. A resultant capacitive network is proposed in order to calculate the electric actuation force. A momentum equation of the droplet has been solved analytically for different radii, inclinations, and actuation voltages. The actuation voltage has been varied from 1 to 100 V. The radius of the droplet footprint is varied from 5 to 20 mm. The effect of different inclination angles (ranging 5°–75°) on downward slipping, upward climbing, and static droplets have been captured. An increase in surface inclination strongly affects the actuation required for droplet transition, which triggers the change in the velocity of the drop. Further, the study also shows the effect of different droplet radii varied from 5 to 20 mm on the actuation voltage and velocity. It has been observed that an increase in droplet size leads to a decrease in velocity and transition voltage for a change in mobility direction.