Spreading Dynamics of Droplet Impact on a Wedge-Patterned Biphilic Surface

Featured Application This work can be used in the droplet harvest process, for droplet impact on a solid surface with a wettable gradient like rain harvest and spray collection, as well as for regulation in a microchannel by spontaneous droplet spreading and migration. Abstract The influence of apex angle and tilting angle on droplet spreading dynamics after impinging on wedge-patterned biphilic surface has been experimentally investigated. Once the droplet contacts the wedge-patterned biphilic surface, it spreads radially on the surface, with a tendency toward a more hydrophilic area. After reaching the maximum spreading diameter, the droplet contracts back. From the experimental results, the normalized diameter ) was found to be related with the Weber number ( as beta similar to root alpha tau.