To grate a liquid into tiny droplets by its impact on a hydrophobic micro-grid

Abstract

We report on experiments of drop impacting a hydrophobic micro-grid, of typical spacing a few tens of $\mu$m. Above a threshold in impact speed, liquid emerges to the other side, forming micro-droplets of size about that of the grid holes. We propose a method to produce either a mono-disperse spray or a single tiny droplet of volume as small as a few picoliters corresponding to a volume division of the liquid drop by a factor of up to 10${}^5$. We also discuss the discrepancy of the measured thresholds with that predicted by a balance between inertia and capillarity.

3 pages, 5 figures, Accepted for publication in Applied Physics Letters

References in corpus (1)

• Bouncing or sticky droplets: impalement transitions on superhydrophobic micropatterned surfaces

Cited by in corpus (2)

• Droplet impact of Newtonian fluids and blood on simple fabrics: effect of fabric pore size and underlying substrate
• Droplet penetration through an inclined mesh