Water droplet patterns
including evenly-spaced droplets (C,H), paired droplets (B), ribbons
(F,I), and helices (J) are among those formed in a recent study of fluids
in microfluidic channels. Researchers were surprised to discover such
complex patterns in conduits with dimensions on the order of tens of
microns, where liquids usually exhibit simple, linear flow behaviors.
The patterns were formed at the juncture of two microfluidic channels,
one filled with water and the other containing an oil/surfactant mixture.
The numbers to the right of the images indicate the relative pressures
(in psi) of the water and oil that generated the various patterns.
et al, Physical Review Letters, 30 April 2001
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