세미나

When a water drop is impinged upon superhydrophobic surfaces, various interesting physical phenomena can occur depending on physical structures on the surfaces. In this talk, I will focus on two phenomena during drop impact: the contact time between the drop and the surface and the water penetration when the surface has micropores.

First, I will present how the contact time during drop impact can change due to the curvature of superhydrophobic surfaces, while proposing a scaling model that successfully captures the influence of impact velocity and surface curvature on the contact time. Also, I will show that the contact time reduction on superhydrophobic surfaces having millimetric structures does not lead to the decrease of the thermal interaction during drop impact between the water drop and the surface due to the concomitant increase of the contact area.

Second, I will show how the water penetrates through superhydrophobic micropores. On superhydrophobic meshes, it is observed that two different water penetration mechanisms are present, which are explained with a scaling argument. Moreover, I will show how to utilize the penetrated water for engineering applications: energy harvesting and microdroplet printing.