Study on Droplet Movement on Superhydrophobic Surfaces under Electric Fields

Abstract

The phenomenon of droplet movement on superhydrophobic surfaces under electric fields was researched by the two-dimensional phase field simulation model. The electrohydrodynamics behaviors of droplets with the contact angle of 150° were taken as a typical description to show the time-lapse morphology evolutions, which droplets were respectively located the center-left 2 mm, center and center-right 2 mm between the two electrodes. And movement behaviors of droplets with contact angles of 120°, 150°, 160° and 170° under the same volume and conditions were quantitatively compared. Simulation results indicate that under the dielectrophoretic (DEP) force, droplets slide to the nearer electrode in the horizontal direction and oscillate with gradually damped amplitudes and periods in the vertical direction. Droplets with lager contact angles move faster and have lager oscillate amplitudes and periods in the vertical direction. This work provides intuitive representations and theoretical supports of electrohydrodynamics behaviors of droplets with different contact angles on superhydrophobic surfaces under the non-uniform electric field formed by two parallel electrodes, which has directive significance to control droplet shape or movement.