Abstract
We present numerical investigations on generating droplets in both single and double T-junction microfluidic devices using the Volume of Fluid (VOF) method. We validate our 2D simulation results with an experimental data reported in the past. The average pressure in the channel increases by 6% and capillary number by 16% for an increase in the width of side-channel from 50 μm to 100 μm in a single T-junction device. Similar increase in average pressure and capillary number is seen, for the increase in the width of one of the side channel in double T-junction device. The temporal variation of pressure in both the side channels shows that the pressure is lesser in the wider side channel. The average pressure in the channel decreases by 75% and capillary number by 15% for an increase in width of the main channel from 50 μm to 100 μm in a single T-junction device. Similar decrease in average pressure and capillary number is seen for the increase in the width of the main channel in double T-junction device. A gradual increase in the width of the main channel shows that, droplets generated in alternate regime when the width of the main channel is 1.4 times the width of side channel. In this regime, the temporal variation in pressure show a periodic change in both the side channel. Finally, in double T-junction device, the addition of surfactant has no significant effect on droplet generation in merging regime but it is seen in alternate regime.
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References
Amaya-Bower, L., Lee, T.: Lattice Boltzmann simulations of bubble formation in a microfluidic T-junction. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 369, 2405–2413 (2011). https://doi.org/10.1098/rsta.2011.0025
Arias, S., Montlaur, A.: Numerical and Experimental Study of the Squeezing-to-Dripping Transition in a T-Junction. Microgravity Sci Technol 32, 687–697 (2020). https://doi.org/10.1007/s12217-020-09794-z
Bashir, S., Rees, J.M., Zimmerman, W.B.: Simulations of microfluidic droplet formation using the two-phase level set method. Chem Eng Sci 66, 4733–4741 (2011). https://doi.org/10.1016/j.ces.2011.06.034
Bashir, S., Solvas, XCi., Bashir, M., et al.: Dynamic wetting in microfluidic droplet formation. BioChip J 8, 122–128 (2014). https://doi.org/10.1007/s13206-014-8207-y
Belousov, K.I., Filatov, N.A., Kukhtevich, I.V., et al.: An asymmetric flow-focusing droplet generator promotes rapid mixing of reagents. Sci Rep 11, 8797 (2021). https://doi.org/10.1038/s41598-021-88174-y
Beneyton, T., Wijaya, I.P.M., Postros, P., et al.: High-throughput screening of filamentous fungi using nanoliter-range droplet-based microfluidics. Sci Rep 6, 1–10 (2016). https://doi.org/10.1038/srep27223
Brackbill, J.U., Kothe, D.B., Zemach, C.: A continuum method for modeling surface tension. J Comput Phys 100, 335–354 (1992). https://doi.org/10.1016/0021-9991(92)90240-Y
Brouzes, E., Medkova, M., Savenelli, N., et al.: Droplet microfluidic technology for single-cell high-throughput screening. PNAS 106, 14195–14200 (2009). https://doi.org/10.1073/pnas.0903542106
Datta, S.S., Abbaspourrad, A., Amstad, E., et al.: 25th Anniversary Article: Double Emulsion Templated Solid Microcapsules: Mechanics And Controlled Release. Adv Mater 26, 2205–2218 (2014). https://doi.org/10.1002/adma.201305119
Dreyfus, R., Tabeling, P., Willaime, H.: Ordered and Disordered Patterns in Two-Phase Flows in Microchannels. Phys Rev Lett 90, 144505 (2003). https://doi.org/10.1103/PhysRevLett.90.144505
Fidalgo, L.M., Abell, C., Huck, W.T.S.: Surface-induced droplet fusion in microfluidic devices. Lab Chip 7, 984–986 (2007). https://doi.org/10.1039/B708091C
Garstecki, P., Fuerstman, M.J., Stone, H.A., Whitesides, G.M.: Formation of droplets and bubbles in a microfluidic T-junction—scaling and mechanism of break-up. Lab Chip 6, 437–446 (2006). https://doi.org/10.1039/B510841A
Glawdel, T., Ren, C.L.: Droplet formation in microfluidic T-junction generators operating in the transitional regime. III. Dynamic surfactant effects. Phys Rev E 86, 026308 (2012). https://doi.org/10.1103/PhysRevE.86.026308
Gupta, A., Kumar, R.: Flow regime transition at high capillary numbers in a microfluidic T-junction: Viscosity contrast and geometry effect. Phys Fluids 22, 122001 (2010). https://doi.org/10.1063/1.3523483
Gupta, A., Matharoo, H.S., Makkar, D., Kumar, R.: Droplet formation via squeezing mechanism in a microfluidic flow-focusing device. Comput Fluids 100, 218–226 (2014). https://doi.org/10.1016/j.compfluid.2014.05.023
Han, W., Chen, X.: New insights into the pressure during the merged droplet formation in the squeezing time. Chem Eng Res Des 145, 213–225 (2019a). https://doi.org/10.1016/j.cherd.2019.03.002
Han, W., Chen, X.: Effect of Geometry Configuration on the Merged Droplet Formation in a Double T-Junction. Microgravity Sci Technol 31, 855–864 (2019b). https://doi.org/10.1007/s12217-019-09720-y
Hirama, H., Torii, T.: One-to-one encapsulation based on alternating droplet generation. Sci Rep 5, 15196 (2015). https://doi.org/10.1038/srep15196
Hoang, P.H., Dien, L.Q.: Fast synthesis of an inorganic–organic block copolymer in a droplet-based microreactor. RSC Adv 4, 8283–8288 (2014). https://doi.org/10.1039/C3RA45747H
Hong, Y., Wang, F.: Flow rate effect on droplet control in a co-flowing microfluidic device. Microfluid Nanofluid 3, 341–346 (2007). https://doi.org/10.1007/s10404-006-0134-3
Hung, L.-H., Choi, M.K., Tseng, W.-Y., et al.: Alternating droplet generation and controlled dynamic droplet fusion in microfluidic device for CdS nanoparticle synthesis. Lab Chip 6, 174–178 (2006). https://doi.org/10.1039/B513908B
Hung, L.-H., Teh, S.-Y., Jester, J., Lee, A.P.: PLGA micro/nanosphere synthesis by droplet microfluidic solvent evaporation and extraction approaches. Lab Chip 10, 1820–1825 (2010). https://doi.org/10.1039/C002866E
Jin, B.-J., Yoo, J.Y.: Visualization of droplet merging in microchannels using micro-PIV. Exp Fluids 52, 235–245 (2012). https://doi.org/10.1007/s00348-011-1221-0
Kemna, E.W.M., Schoeman, R.M., Wolbers, F., et al.: High-yield cell ordering and deterministic cell-in-droplet encapsulation using Dean flow in a curved microchannel. Lab Chip 12, 2881–2887 (2012). https://doi.org/10.1039/C2LC00013J
Kong, T., Wu, J., Yeung, K.W.K., et al.: Microfluidic fabrication of polymeric core-shell microspheres for controlled release applications. Biomicrofluidics 7, 044128 (2013). https://doi.org/10.1063/1.4819274
Lee, T.Y., Choi, T.M., Shim, T.S., et al.: Microfluidic production of multiple emulsions and functional microcapsules. Lab Chip 16, 3415–3440 (2016). https://doi.org/10.1039/C6LC00809G
Leshansky, A.M., Pismen, L.M.: Breakup of drops in a microfluidic T junction. Phys Fluids 21, 023303 (2009). https://doi.org/10.1063/1.3078515
Li, P., Fan, M., Sun, L., et al.: Numerical Simulation of Bubble Formation in a Co-Flowing Liquid in Microfluidic Chip. Microgravity Sci Technol 32, 1–9 (2020). https://doi.org/10.1007/s12217-019-09729-3
Li, X.-B., Li, F.-C., Yang, J.-C., et al.: Study on the mechanism of droplet formation in T-junction microchannel. Chem Eng Sci 69, 340–351 (2012). https://doi.org/10.1016/j.ces.2011.10.048
Liu, H., Zhang, Y.: Droplet formation in a T-shaped microfluidic junction. J Appl Phys 106, 034906 (2009). https://doi.org/10.1063/1.3187831
Liu, K., Qin, J.: Droplet-fused microreactors for room temperature synthesis of nanoscale needle-like hydroxyapatite. Nanotechnology 24, 125602 (2013). https://doi.org/10.1088/0957-4484/24/12/125602
Nasser, G.A., Fath El-Bab, A.M.R., Abdel-Mawgood, A.L., et al.: CO2 Laser Fabrication of PMMA Microfluidic Double T-Junction Device with Modified Inlet-Angle for Cost-Effective PCR Application. Micromachines 10, 678 (2019). https://doi.org/10.3390/mi10100678
Nekouei, M., Vanapalli, S.A.: Volume-of-fluid simulations in microfluidic T-junction devices: Influence of viscosity ratio on droplet size. Phys. Fluids 29, 032007 (2017). https://doi.org/10.1063/1.4978801
Ngo, I.-L., Dang, T.-D., Byon, C., Joo, S.W.: A numerical study on the dynamics of droplet formation in a microfluidic double T-junction. Biomicrofluidics 9, 024107 (2015). https://doi.org/10.1063/1.4916228
Nunes, J.K., Tsai, S.S.H., Wan, J., Stone, H.A.: Dripping and jetting in microfluidic multiphase flows applied to particle and fiber synthesis. J Phys D Appl Phys 46 (2013).https://doi.org/10.1088/0022-3727/46/11/114002
O’Brien, C.M., Rood, K.D., Bhattacharyya, K., et al.: Capture of circulating tumor cells using photoacoustic flowmetry and two phase flow. JBO 17, 061221 (2012). https://doi.org/10.1117/1.JBO.17.6.061221
Peng, L., Yang, M., Guo, S., et al.: The effect of interfacial tension on droplet formation in flow-focusing microfluidic device. Biomed Microdevices 13, 559–564 (2011). https://doi.org/10.1007/s10544-011-9526-6
Saqib, M., Şahinoğlu, O.B., Erdem, E.Y.: Alternating Droplet Formation by using Tapered Channel Geometry. Sci Rep 8, 1–9 (2018). https://doi.org/10.1038/s41598-018-19966-y
Seo, M., Paquet, C., Nie, Z., et al.: Microfluidic consecutive flow-focusing droplet generators. Soft Matter 3, 986–992 (2007). https://doi.org/10.1039/B700687J
Shi, Y., Tang, G.H., Xia, H.H.: Lattice Boltzmann simulation of droplet formation in T-junction and flow focusing devices. Comput Fluids 90, 155–163 (2014). https://doi.org/10.1016/j.compfluid.2013.11.025
Song, H., Li, H.-W., Munson, M.S., et al.: On-Chip Titration of an Anticoagulant Argatroban and Determination of the Clotting Time within Whole Blood or Plasma Using a Plug-Based Microfluidic System. Anal Chem 78, 4839–4849 (2006). https://doi.org/10.1021/ac0601718
Soroor, M., Zabetian Targhi, M., Tabatabaei, S.A.: Numerical and experimental investigation of a flow focusing droplet-based microfluidic device. Eur J Mech B Fluids 89, 289–300 (2021). https://doi.org/10.1016/j.euromechflu.2021.06.013
Surya, H.P.N., Parayil, S., Banerjee, U., et al.: Alternating and merged droplets in a double T-junction microchannel. BioChip J 9, 16–26 (2015). https://doi.org/10.1007/s13206-014-9103-1
Tadros, T.F.: Emulsion Formation, Stability, and Rheology. In: Emulsion Formation and Stability. John Wiley & Sons, Ltd, 1–75 (2013)
Totlani, K., Hurkmans, J.-W., van Gulik, W.M., et al.: Scalable microfluidic droplet on-demand generator for non-steady operation of droplet-based assays. Lab Chip 20, 1398–1409 (2020). https://doi.org/10.1039/C9LC01103J
Um, E., Lee, D.-S., Pyo, H.-B., Park, J.-K.: Continuous generation of hydrogel beads and encapsulation of biological materials using a microfluidic droplet-merging channel. Microfluid Nanofluid 5, 541–549 (2008). https://doi.org/10.1007/s10404-008-0268-6
Vivek, R.: Computational Flow Modeling for Chemical Reactor Engineering, Volume 5 - 1st Edition (2019). https://www.elsevier.com/books/computational-flow-modeling-for-chemical-reactor-engineering/ranade/978-0-12-576960-0. Accessed 24 Nov 2019
Wojnicki, M., Luty-Błocho, M., Hessel, V., et al.: Micro Droplet Formation towards Continuous Nanoparticles Synthesis. Micromachines 9, 248 (2018). https://doi.org/10.3390/mi9050248
Xu, J.H., Li, S.W., Tan, J., et al.: Preparation of highly monodisperse droplet in a T-junction microfluidic device. AIChE J 52, 3005–3010 (2006). https://doi.org/10.1002/aic.10924
Yan, Y., Guo, D., Wen, S.Z.: Numerical simulation of junction point pressure during droplet formation in a microfluidic T-junction. Chem Eng Sci 84, 591–601 (2012). https://doi.org/10.1016/j.ces.2012.08.055
Yesiloz, G., Boybay, M.S., Ren, C.L.: Label-free high-throughput detection and content sensing of individual droplets in microfluidic systems. Lab Chip 15, 4008–4019 (2015). https://doi.org/10.1039/C5LC00314H
Zhang, Y., Jiang, H.-R.: A review on continuous-flow microfluidic PCR in droplets: Advances, challenges and future. Anal Chim Acta 914, 7–16 (2016). https://doi.org/10.1016/j.aca.2016.02.006
Zheng, B., Tice, J.D., Ismagilov, R.F.: Formation of Droplets of Alternating Composition in Microfluidic Channels and Applications to Indexing of Concentrations in Droplet-Based Assays. Anal Chem 76, 4977–4982 (2004a). https://doi.org/10.1021/ac0495743
Zheng, B., Tice, J.D., Roach, L.S., Ismagilov, R.F.: 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 Int Ed 43, 2508–2511 (2004b). https://doi.org/10.1002/anie.200453974
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Raja, S., Satyanarayan, M.N., Umesh, G. et al. Numerical Investigations on Alternate Droplet Formation in Microfluidic Devices. Microgravity Sci. Technol. 33, 71 (2021). https://doi.org/10.1007/s12217-021-09917-0
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DOI: https://doi.org/10.1007/s12217-021-09917-0