Abstract
In this work the design of a segmented flow microfluidic device is presented that allows droplet splitting ratios from 1:1 up to 20:1. This ratio can be dynamically changed on chip by altering an additional oil flow. The design was fabricated in PDMS chips using the standard SU-8 mold technique and does not require any valves, membranes, optics or electronics. To avoid a trial and error approach, fabricating and testing several designs, a computational fluid dynamics model was developed and validated for droplet formation and splitting. The model was used to choose between several variations of the splitting T-junction with the extra oil inlet, as well to predict the additional flow rate needed to split the droplets in various ratios. Experimental and simulated results were in line, suggesting the model’s suitability to optimize future designs and concepts. The resulting asymmetric droplet splitter design opens possibilities for controlled sampling and improved magnetic separation in bio-assay applications.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Anna SL, Bontoux N, Stone HA (2003) Formation of dispersions using “flow focusing” in microchannels. Appl Phys Lett 82:364. doi:10.1063/1.1537519
Atalay YT, Verboven P, Vermeir S et al (2008) Design optimization of an enzymatic assay in an electrokinetically-driven microfluidic device. Microfluid Nanofluid 5:837–849. doi:10.1007/s10404-008-0291-7
Atalay YT, Witters D, Vermeir S et al (2009) Design and optimization of a double-enzyme glucose assay in microfluidic lab-on-a-chip. Biomicrofluidics 3:44103. doi:10.1063/1.3250304
Brackbill J, Kothe D, Zemach C (1992) A continuum method for modeling surface tension. J Comput Phys 335354:335–354. doi:10.1016/0021-9991(92)90240-Y
Christopher GF, Bergstein J, End NB et al (2009) Coalescence and splitting of confined droplets at microfluidic junctions. Lab Chip 9:1102–1109. doi:10.1039/b813062k
De Lózar A, Juel A, Hazel AL (2008) The steady propagation of an air finger into a rectangular tube. J Fluid Mech 614:173. doi:10.1017/S0022112008003455
De Menech M, Garstecki P, Jousse F, Stone HA (2008) Transition from squeezing to dripping in a microfluidic T-shaped junction. J Fluid Mech 595:141–161. doi:10.1017/S002211200700910X
Dreyfus R, Tabeling P, Willaime H (2003) Ordered and disordered patterns in two-phase flows in microchannels. Phys Rev Lett 90:1–4. doi:10.1103/PhysRevLett.90.144505
Duffy DC, McDonald JC, Schueller OJ, Whitesides GM (1998) Rapid prototyping of microfluidic systems in poly(dimethylsiloxane). Anal Chem 70:4974–4984. doi:10.1021/ac980656z
Garstecki P, Fuerstman MJ, Stone HA, Whitesides GM (2006) Formation of droplets and bubbles in a microfluidic T-junction-scaling and mechanism of break-up. Lab Chip 6:437–446
Grodrian A, Metze J, Henkel T et al (2004) Segmented flow generation by chip reactors for highly parallelized cell cultivation. Biosens Bioelectron 19:1421–1428. doi:10.1016/j.bios.2003.12.021
Günther A, Jensen KF (2006) Multiphase microfluidics: from flow characteristics to chemical and materials synthesis. Lab Chip 6:1487–1503. doi:10.1039/b609851g
Hirt C, Nichols B (1981) Volume of fluid (VOF) method for the dynamics of free boundaries. J Comput Phys 39:201–225. doi:10.1016/0021-9991(81)90145-5
Holtze C, Rowat AC, Agresti JJ et al (2008) Biocompatible surfactants for water-in-fluorocarbon emulsions. Lab Chip 8:1632–1639. doi:10.1039/b806706f
Huebner A, Srisa-Art M, Holt DJ et al (2007) Quantitative detection of protein expression in single cells using droplet microfluidics. Chem Commun 1218–1220. doi:10.1039/b618570c
Huebner A, Olguin LF, Bratton D et al (2008) Development of quantitative cell-based enzyme assays in microdroplets. Anal Chem 80:3890–3896. doi:10.1021/ac800338z
Huebner A, Bratton D, Whyte G et al (2009) Static microdroplet arrays: a microfluidic device for droplet trapping, incubation and release for enzymatic and cell-based assays. Lab Chip 9:692–698. doi:10.1039/b813709a
Kolb WB, Cerro RL (1993) The motion of long bubbles in tubes of square cross section. Phys Fluids A Fluid Dyn 5:1549. doi:10.1063/1.858832
Link DR, Anna SL, Weitz DA, Stone HA (2004) Geometrically mediated breakup of drops in microfluidic devices. Phys Rev Lett 92:054503. doi:10.1103/PhysRevLett.92.054503
Liu H, Zhang Y (2011) Droplet formation in microfluidic cross-junctions. Phys Fluids 23:082101. doi:10.1063/1.3615643
Lombardi D, Dittrich PS (2011) Droplet microfluidics with magnetic beads: a new tool to investigate drug-protein interactions. Anal Bioanal Chem 399:347–352. doi:10.1007/s00216-010-4302-7
Nie J, Kennedy RT (2010) Sampling from nanoliter plugs via asymmetrical splitting of segmented flow. Anal Chem 82:7852–7856. doi:10.1021/ac101723x
Nightingale AM, De Mello JC (2010) Microscale synthesis of quantum dots. J Mater Chem 20:8454. doi:10.1039/c0jm01221a
Nisisako T, Torii T (2008) Microfluidic large-scale integration on a chip for mass production of monodisperse droplets and particles. Lab Chip 8:287–293. doi:10.1039/b713141k
Niu X, Gulati S, Edel JB, DeMello AJ (2008) Pillar-induced droplet merging in microfluidic circuits. Lab Chip 8:1837–1841. doi:10.1039/b813325e
Olbricht WL (1996) Pore-scale prototypes of multiphase flow in porous media. Annu Rev Fluid Mech 28:187–213. doi:10.1146/annurev.fl.28.010196.001155
Pan X, Zeng S, Zhang Q et al (2011) Sequential microfluidic droplet processing for rapid DNA extraction. Electrophoresis 1–7. doi:10.1002/elps.201100078
Pekin D, Skhiri Y, Baret J-C et al (2011) Quantitative and sensitive detection of rare mutations using droplet-based microfluidics. Lab Chip 11:2156–2166. doi:10.1039/c1lc20128j
Sivasamy J, Wong T-N, Nguyen N-T, Kao LT-H (2011) An investigation on the mechanism of droplet formation in a microfluidic T-junction. Microfluid Nanofluid 11:1–10. doi:10.1007/s10404-011-0767-8
Song H, Ismagilov RF (2003) Millisecond kinetics on a microfluidic chip using nanoliters of reagents. J Am Chem Soc 125:14613–14619. doi:10.1021/ja0354566
Song H, Tice JD, Ismagilov RF (2003) A microfluidic system for controlling reaction networks in time. Angew Chem 115:792–796. doi:10.1002/ange.200390172
Srisa-Art M, deMello AJ, Edel JB (2010) High-efficiency single-molecule detection within trapped aqueous microdroplets. J phys chem B 114:15766–15772. doi:10.1021/jp105749t
Thorsen T, Roberts R, Arnold F, Quake SR (2001) Dynamic pattern formation in a vesicle-generating microfluidic device. Phys Rev Lett 86:4163–4166. doi:10.1103/PhysRevLett.86.4163
Whitesides GM (2006) The origins and the future of microfluidics. Nature 442:368–373. doi:10.1038/nature05058
Yamada M, Doi S, Maenaka H et al (2008) Hydrodynamic control of droplet division in bifurcating microchannel and its application to particle synthesis. J Colloid Interface Sci 321:401–407. doi:10.1016/j.jcis.2008.01.036
Zheng B, Tice JD, Roach LS, Ismagilov RF (2004) A droplet-based, composite PDMS/glass capillary microfluidic system for evaluating protein crystallization conditions by microbatch and vapor-diffusion methods with on-chip X-ray diffraction. Angew Chem 43:2508–2511. doi:10.1002/anie.200453974
Acknowledgments
The authors thank the Flemish Institute for the Promotion of Innovation through Science and Development (IWT grant: 81166), the Flemish Fund for Scientific Research (FWO grant G0767.09 and Postdoctoral mandate Frederik Ceyssens), KU Leuven (OT project 08/023) and EU FP-7 Marie-Curie ITN-BioMax. Special thanks go to Mark Romanowski and Ralph Sperling from the Weitz lab of Harvard University who freely provided their custom perfluorinated surfactant as well as priceless advice.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Verbruggen, B., Tóth, T., Atalay, Y.T. et al. Design of a flow-controlled asymmetric droplet splitter using computational fluid dynamics. Microfluid Nanofluid 15, 243–252 (2013). https://doi.org/10.1007/s10404-013-1139-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10404-013-1139-3