To grate a liquid into tiny droplets by its impact on a hydrophobic microgrid

P. Brunet , F. Lapierre , Farzam Zoueshtiagh , V. Thomy , A. Merlen

We report on experiments of drop impacting a hydrophobic micro-grid, of typical spacing a few tens of µm. Above a threshold in impact speed, liquid emerges to the other side, forming microdroplets 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 105. We also discuss the discrepancy of the measured thresholds with that predicted by a balance between inertia and capillarity

Domaines: Mécanique des fluides [physics.class-ph]; Micro et nanotechnologies/Microélectronique

P. Brunet, F. Lapierre, Farzam Zoueshtiagh, V. Thomy, A. Merlen. To grate a liquid into tiny droplets by its impact on a hydrophobic microgrid. Applied Physics Letters, 2009, 95 (25), pp.254102. ⟨10.1063/1.3275709⟩. ⟨hal-00469669⟩