Directed droplet motion induced by vibration of the solid support

摘要

The unidirectional motion of a droplet settled on an energetically heterogeneous surface undergoing mechanicalrnvibration is studied by means of simulations with a finite element method performed by the Surface Evolverrnsimulation program. The surface energy inhomogeneities are represented by a pattern of a series of parallel stripesrnof monotonically increasing width and two alternating contact angles. In certain circumstances, the observed shift ofrnthe droplet is perpendicular to the stripes and directed toward the increasing width of the stripes. The influence ofrnmodel parameters on the trajectory of the droplet is discussed. A full profile of the droplet energy along the dropletrntrajectory was estimated on the basis of density distribution of positions occupied by the droplet along the travelrncoordinates. The influence of model parameters on the trajectory of the droplet is discussed. On the basis of thernasymmetric properties of the energy profile, the ratchet mechanism of unidirectional droplet motion was postulated.