Geometry-controlled droplet generation in head-on microfluidic devices

Applied Physics Letters

Volumn 93, Issue 15, 2008, Pages

  Shui, Lingling ^a   Mugele, Frieder ^b   Van Den Berg, Albert ^a   Eijkel, Jan C T ^a  

^a UNIVERSITY OF TWENTE   (Netherlands)

^b UNIVERSITY OF TWENTE   (Netherlands)

Author keywords

[No Author keywords available]

Indexed keywords

CALCIUM; DROP FORMATION; FLUIDIC DEVICES;

CAPILLARY INSTABILITIES; CAPILLARY NUMBERS; DROPLET GENERATIONS; DROPLET VOLUMES; MICROFLUIDIC DEVICES; SHEAR FORCES; SURFACE CONFIGURATIONS;

DROPS;

EID: 54149097192     PISSN: 00036951     EISSN: None     Source Type: Journal    
DOI: 10.1063/1.3000624     Document Type: Article

References (13)

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12. We rationalize the stabilization as follows. The fastest growing unstable modes in the classical Rayleigh plateau instability distribute the liquid only on a local scale, i.e., they would force liquid from the junction area into the entrance of the adjacent constriction channel. Such a perturbation, however, would experience a restoring force because it requires forcing the liquid-liquid interface further into the corners. As a consequence, such perturbations are no longer unstable and the breakup can only occur through slower nonlocal perturbations. Note that this picture is also different from the convective stabilization of confined jets discussed by P. Guillot, Phys. Rev. Lett. 99, 104502 (2007), operated at much higher Ca.
13. See EPAPS Document No. E-APPLAB-93-021842. Movie 1 shows oil droplet generated in a restriction channel with dimensions: h=10 μm, w=10 μm, l=100 μm at flow rates of Qw = Qo =0.01 μL/min. Movie 2 shows oil droplet generated in a restriction channel with dimensions: h=10 μm, w=10 μm, l=1000 μm at flow rates of Qw = Qo =0.0025 μL/min. For more information on EPAPS, see http://www.aip.org/pubservs/epaps.html.