How micropatterns and air pressure affect splashing on surfaces

Abstract

We experimentally investigate the splashing mechanism of a millimeter-sized ethanol drop impinging on a structured solid surface, comprised of micro-pillars, through side-view and top-view high speed imaging. By increasing the impact velocity we can tune the impact outcome from a gentle deposition to a violent splash, at which tiny droplets are emitted as the liquid sheet spreads laterally. We measure the splashing threshold for different micropatterns and find that the arrangement of the pillars significantly affects the splashing outcome. In particular, directional splashing in direction in which air flow through pattern is possible. Our top-view observations of impact dynamics reveal that an trapped air is responsible for the splashing. Indeed by lowering the pressure of the surrounding air we show that we can suppress the splashing in the explored parameter regime.

7 pages, 9 figures

References in corpus (4)

• Drop Splashing on a Dry Smooth Surface
• Drop impact upon micro- and nanostructured superhydrophobic surfaces
• Liquid drop splashing on smooth, rough and textured surfaces
• Splashing of liquids: interplay of surface roughness with surrounding gas

Cited by in corpus (18)

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• Lattice-Boltzmann simulations of the drag force on a sphere approaching a superhydrophobic striped plane
• Crown rupture during droplet impact on a dry smooth surface at increased pressure
• Drop impact on wet granular beds: water-content effects on the cratering