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Pillar-induced droplet merging in microfluidic circuits

Niu, Xize, Gulati, Shelly, Edel, Joshua B. and deMello, Andrew J. (2008) Pillar-induced droplet merging in microfluidic circuits Lab on a Chip, 8, (11), pp. 1837-1841. (doi:10.1039/b813325e).

Record type: Article


A novel method is presented for controllably merging aqueous microdroplets within segmented flow microfluidic devices. Our approach involves exploiting the difference in hydrodynamic resistance of the continuous phase and the surface tension of the discrete phase through the use of passive structures contained within a microfluidic channel. Rows of pillars separated by distances smaller than the representative droplet dimension are installed within the fluidic network and define passive merging elements or chambers. Initial experiments demonstrate that such a merging element can controllably adjust the distance between adjacent droplets. In a typical scenario, a droplet will enter the chamber, slow down and stop. It will wait and then merge with the succeeding droplets until the surface tension is overwhelmed by the hydraulic pressure. We show that such a merging process is independent of the inter-droplet separation but rather dependent on the droplet size. Moreover, the number of droplets that can be merged at any time is also dependent on the mass flow rate and volume ratio between the droplets and the merging chamber. Finally, we note that the merging of droplet interfaces occurs within both compressing and the decompressing regimes.

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e-pub ahead of print date: 8 October 2008
Published date: 2008
Organisations: Mechatronics


Local EPrints ID: 199897
ISSN: 1473-0197
PURE UUID: a0bd00e6-ed79-4e14-a7f7-e1bee45bca19

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Date deposited: 21 Oct 2011 15:45
Last modified: 18 Jul 2017 11:15

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Author: Xize Niu
Author: Shelly Gulati
Author: Joshua B. Edel
Author: Andrew J. deMello

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