Control of Pressure-Driven Microdroplet Formation and Optimum Encapsulation in Microfluidic System

  • Mathias Girault
  • Akihiro Hattori
  • Hyonchol Kim
  • Kenji Matsuura
  • Masao Odaka
  • Hideyuki Terazono
  • Kenji YasudaEmail author
Conference paper


Formation of stable micro-droplets in multiphase flow is an important step to perform numerous microfluidic applications such as sorting experiments. We herein investigate the conditions of formation of stable micro-droplets using a flow focusing microfluidic device. Two single phases and four different multiphase flow regimes were observed depending on the pressures of fluids. By tuning sample stream pressure against fixed lower oil stream pressure, stable droplet regime can create microenvironment with a diameter ranged from 30 µm to 140 µm. Results obtained show that the formation of strictly size controlled droplets can encapsulate single cell-sized bead into droplet. Moreover, the limit between unstable and stable droplet regimes was the most suitable to efficiently encapsulate cell-sized bead in droplet sorting application. This limit can be precisely monitored by using the change of the droplet speed found at the threshold between these two regimes.


Microfluidics Encapsulation Flow control 



This work was supported by Kanagawa Prefector’s local basic science funding for the On-chip Cellomics Project at the Kanagawa Academy of Science and Technology. This research was also supported by JST, CREST. We gratefully thank Ms. H. Mikami and Ms. M. Hasegawa for their helps during the experiments.


  1. Anna SL, Bontoux N, Stone HA (2003) Formation of dispersions using ‘‘flow focusing’’ in microchannels. Apply Phys Lett 82:364–366CrossRefGoogle Scholar
  2. Avila K, Moxey D, De Lozar A, Avila M, Barkley D, Hof B (2011) The onset of turbulence in pipe flow. Science 333:192–196CrossRefGoogle Scholar
  3. Baroud CN, Gallaire F, Dangla R (2010) Dynamics of microfluidic droplets. Lab Chip 10:2032–2045CrossRefGoogle Scholar
  4. Brody JP, Yager P, Goldstein RE, Austin RH (1996) Biotechnology at low Reynolds numbers. Biophys J 71:3430–3441CrossRefGoogle Scholar
  5. Dreyfus R, Tabeling P, Willaime H (2003) Ordered and disordered patterns in two-phase flows in microchannel. Phys Rev Lett 90:144505CrossRefGoogle Scholar
  6. Duffy DC, McDonald JC, Schueller OJA, Whitesides GM (1998) Rapid prototyping of microfluidics system in poly(dimethylsiloxane). Anal Chem 70:4974–4984CrossRefGoogle Scholar
  7. Edd JF, Di Carlo D, Humphry KJ, Köster S, Irimia D, Weitz DA, Toner M (2008) Controlled encpsulation of single-cells into monodiperse picolitre drop. Lab Chip 8:1262–1264CrossRefGoogle Scholar
  8. Gu H, Duits MHG, Mugele F (2011) Droplets formation and merging in two-phase flow microfluidics. Int J Mol Sci 12:2572–2597CrossRefGoogle Scholar
  9. Jakiela S, Makulska S, Korczyk PM, Garstecki P (2011) Speed of flow of individual droplets in microfluidic channels as a function of the capillary number, volume of droplets and contrast of viscosities. Lab Chip 11:3603–3608CrossRefGoogle Scholar
  10. Kandlikar SG (2005) Roughness effects at microscale – reassessing Nikuradse’s experiments on liquid flow in rough tubes. Bull Pol Ac Tech 53:343–349Google Scholar
  11. Köster S, Angilè FE, Duan H, Agresti JJ, Wintner A, Schmitz C, Rowat AC, Merten CA, Pisignano D, Griffiths AD, Weitz DA (2008) Drop-based microfluidic devices for encapsulation of single cells. Lab Chip 8:1110–1115CrossRefGoogle Scholar
  12. Lee W, Walker LM, Anna SL (2009) Role of geometry and fluid properties in droplet and thread formation processes in planar flow focusing. Phys Fluid 21:032103. Scholar
  13. Li H, Ewoldt R, Olsen MG (2005) Turbulent and transitional velocity measurements in a rectangular microchannel using microscopic particle image velocimetry. Exp Therm Fluid Sci 29:435–446CrossRefGoogle Scholar
  14. Mazutis L, Gilbert J, Urig WL, Weitz DA, Griffiths AD, Heyman JA (2013) Single-cell analysis and sorting using droplet-based microfluidics. Nat Protoc 8:870–891CrossRefGoogle Scholar
  15. Pan L, Arratia PE (2013) A high-shear, low Reynolds number microfluidic rheometer. Microfluid Nanofluid 14:885–894CrossRefGoogle Scholar
  16. Salim A, Fourar M, Pironon J, Sausse J (2008) Oil–water two-phase flow in microchannels: Flow patterns and pressure drop measurements. Can J Chem Eng 86:978–988CrossRefGoogle Scholar
  17. Szumbarski J (2007) Instability of viscous incompressible flow in a channel with transversely corrugated walls. J Theor App Mech Pol 45:659–683Google Scholar
  18. Tice JD, Lyon AD, Ismagilov RF (2004) Effects of viscosity on droplet formation and mixing in microfluidic channels. Anal Chim Acta 507:73–77CrossRefGoogle Scholar
  19. Tice JD, Song H, Lyon AD, Ismagilov RF (2003) Formation of droplets and mixing in multiphase microfluidics at low values of the Reynolds and the capillary numbers. Langmuir 19:9127–9133CrossRefGoogle Scholar
  20. Wang GR, Yang F, Zhao W (2014) There can be turbulence in microfluidics at low Reynolds number. Lab Chip 14:1452–4958CrossRefGoogle Scholar
  21. Ward T, Faivre M, Abkarian M, Stone HA (2005) Microfluidic flow focusing: Drop size and scaling in pressure versus flow-rate-driven pumping. Electrophoresis 26:3716–3724CrossRefGoogle Scholar
  22. Wu L, Chen P, Dong Y, Feng X, Liu BF (2013) Encapsulation of single cells on a microfluidic device integrating droplet generation with fluorescence-activated droplet sorting. Biomed Microdevices 15:553–560CrossRefGoogle Scholar
  23. Zhao Y, Chen G, Yuan Q (2006) Liquid-liquid two-phase flow patterns in a rectangular microchannel. AlChE J 52:4052–4060CrossRefGoogle Scholar
  24. Zhou CF, Yue PT, Feng JJ (2006) Formation of simple and compound drops in microfluidic devices. Phys Fluids 18:092105. Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Mathias Girault
    • 1
  • Akihiro Hattori
    • 1
  • Hyonchol Kim
    • 1
    • 2
  • Kenji Matsuura
    • 1
  • Masao Odaka
    • 1
    • 2
  • Hideyuki Terazono
    • 2
  • Kenji Yasuda
    • 3
    • 4
    • 5
    Email author
  1. 1.Kanagawa Academy of Science and TechnologyTakatsuJapan
  2. 2.Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental UniversityChiyodaJapan
  3. 3.Department of Physics, Faculty of Science and EngineeringWaseda UniversityShinjuku-kuJapan
  4. 4.Waseda Bioscience Research Institute in Singapore (WABIOS)HeliosSingapore
  5. 5.CREST, Japan Science and Technology AgencyKawaguchiJapan

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