微流控器件中的多相流动

陈晓东; 胡国庆

doi:10.6052/1000-0992-14-063

微流控器件中的多相流动

doi: 10.6052/1000-0992-14-063

中国科学院力学研究所非线性力学国家重点实验室, 北京 100190

基金项目: 国家自然科学基金(11272321和11402274)和科技部973计划(2011CB707604)项目资助.

详细信息

通讯作者:
胡国庆, 中国科学院力学研究所非线性力学国家重点实验室研究员, 博士生导师. 现任中国力学学会副秘书长. 曾在美国、加拿大、英国、以色列等国家长期从事研究工作, 目前开展微纳米流体力学机理和微纳流控芯片设计理论的研究, 侧重于微纳尺度颗粒、细胞、液滴、生物大分子等输运及其在生化领域的应用. 主持国家973 计划、国家自然科学基金、中科院知识创新重要方向项目等多项课题. 在ACS Nano, Lab ona Chip, Biosensors & Bioelectronics, Analytica Chimica Acta, Physicsof Fluids, Biomicrofluidcis, Electrophoresis 等国际重要学术期刊发表SCI论文近40篇.

中图分类号: O359
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出版历程
- 收稿日期: 2014-10-08
- 修回日期: 2015-01-27
- 刊出日期: 2015-08-30

Multiphase flow in microfluidic devices

LNM, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China

More Information

Corresponding author: Guoqing HU

摘要

摘要: 微流控技术及微流控器件是近年来发展迅速的多学科交叉研究领域.相比于传统方法, 微流控技术能够实现对微量多相流体的精准操控, 可应用于化学分析、先进材料合成、蛋白质结晶、单细胞培育及检测、信息处理等领域. 该文回顾微流控器件中的多相流动现象, 概述其所涉及的流体力学机理,阐述实现多相微流控的各种方法, 并分析多相微流控技术的应用现状及面临的挑战, 最后总结针对多相微流动问题的数值模拟方法和实验测量技术, 展望多相微流控器件的研究方向及应用前景.
- 微尺度流动 /
- 多相流动 /
- 液滴 /
- 微流控器件
Abstract: Recent years have witnessed the rapid development of microfluidic technology and microfluidic devices as a multi-disciplinary research field. Compared to conventional methods, microfluidic technology enables us to precisely manipulate the small volume of multiphase fluids for chemical analysis, advanced materials synthesis, protein crystalliza-tion, single-cell cultivation and detection, information processing, etc. In this paper, we review the multiphase flow phenomena in microfluidic devices, summarize the fluid mechan-ics involved, describe various methods to achieve multiphase microfluidic flow, and analyze the state-of-the-art of applications and challenges in this field. Finally, numerical simulation methods and experimental measurement techniques for multiphase microflows are provided. Opportunities for future research and application of microfluidic devices are suggested.
- microfluidics /
- multiphase flow /
- droplet /
- microfluidic device

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参考文献(183)

[1]	胡国庆. 2008. 第一届Batchelor 奖获得者Howard Stone 教授研究工作简评. 力学进展, 38: 623-624(Hu G Q, 2008. Brief comments on the research of Professor Howard Stone (the first G.K.Batchelor Prizewinner). Advances in Mechanics, 38: 623-624).
[2]	李战华, 吴健康, 胡国庆, 胡国辉. 2012. 微流控芯片中的流体流动. 北京: 科学出版社.
[3]	林炳承. 2013. 微纳流控芯片实验室. 北京: 科学出版社.
[4]	司廷, 尹协振. 2011. 流动聚焦研究进展及其应用. 科学通报, 56: 537-546 (Si T, Yin X Z. 2011. Progress and application of flow focusing. Chinese Science Bulletin, 56: 537-546).
[5]	王企鲲, 孙仁. 2012. 管流中颗粒\"惯性聚集"现象的研究进展及其在微流动中的应用. 力学进展,42: 692-703 (Wang Q K, Sun R. 2012. Advances in the research on\inertial focus of particles and its application in microfluidics. Advances in Mechanics, 42: 692-703).
[6]	Abate A, Poitzsch A, Hwang Y, Lee J, Czerwinska J, Weitz D. 2009a. Impact of inlet channel geometry on microfluidic drop formation. Physical Review E, 80: 026310.
[7]	Abate A, Weitz D. 2009. High-order multiple emulsions formed in poly(dimethylsiloxane) microfluidics.Small, 5: 2030-2032.
[8]	Abate A, Mary P, Van Steijn V, Weitz D. 2012. Experimental validation of plugging during drop formation in a T-junction. Lab on a Chip, 12: 1516-1521.
[9]	Abate A R, Chen C-H, Agresti J J, Weitz D A. 2009b. Beating Poisson encapsulation statistics using close-packed ordering. Lab on a Chip, 9: 2628-2631.
[10]	Abate A R, Hung T, Mary P, Agresti J J, Weitz D A. 2010a. High-throughput injection with microfluidics using picoinjectors. Proceedings of the National Academy of Sciences, 107: 19163-19166.
[11]	Abate A R, Thiele J, Weinhart M, Weitz D A. 2010b. Patterning microfluidic device wettability using flow confinement. Lab on a Chip, 10: 1774-1776.
[12]	Abate A R, Weitz D A. 2011. Faster multiple emulsification with drop splitting. Lab on a Chip, 11: 1911-1915.
[13]	Adams L, Kodger T E, Kim S-H, Shum H C, Franke T, Weitz D A. 2012. Single step emulsification for the generation of multi-component double emulsions. Soft Matter, 8: 10719-10724.
[14]	Adham A M, Mohd-Ghazali N, Ahmad R. 2013. Thermal and hydrodynamic analysis of microchannel heat sinks: A review. Renewable & Sustainable Energy Reviews, 21: 614-622.
[15]	Adrian R J. 1991. Particle-imaging techniques for experimental fluid mechanics. Annual Review of Fluid Mechanics, 23: 261-304.
[16]	Afkhami S, Leshansky A, Renardy Y. 2011. Numerical investigation of elongated drops in a microfluidic T-junction. Physics of Fluids, 23: 022002.
[17]	Ahn K, Agresti J, Chong H, Marquez M, Weitz D. 2006a. Electrocoalescence of drops synchronized by size-dependent flow in microfluidic channels. Applied Physics Letters, 88: 264105.
[18]	Ahn K, Kerbage C, Hunt T P, Westervelt R, Link D R, Weitz D. 2006b. Dielectrophoretic manipulation of drops for high-speed microfluidic sorting devices. Applied Physics Letters, 88: 024104-024103.
[19]	Aidun C K, Clausen J R. 2010. Lattice-Boltzmann method for complex flows. Annual Review of Fluid Mechanics, 42: 439-472.
[20]	Amirouche F, Zhou Y, Johnson T. 2009. Current micropump technologies and their biomedical applications. Microsystem Technologies, 15: 647-666.
[21]	Anna S L, Bontoux N, Stone H A. 2003. Formation of dispersions using\flow focusing in microchannels.Applied Physics Letters, 82: 364-366.
[22]	Aserin A. 2008. Multiple Emulsion: Technology and Applications, New York: John Wiley & Sons.
[23]	Asmolov E S. 1999. The inertial lift on a spherical particle in a plane Poiseuille flow at large channel Reynolds number. Journal of Fluid Mechanics, 381: 63-87.
[24]	Aulisa E, Manservisi S, Scardovelli R, Zaleski S. 2007. Interface reconstruction with least-squares fit and split advection in three-dimensional Cartesian geometry. Journal of Computational Physics, 225: 2301-2319.
[25]	Ausas R F, Dari E A, Buscaglia G C. 2011. A geometric mass-preserving redistancing scheme for the level set function. International Journal for Numerical Methods in Fluids, 65: 989-1010.
[26]	Baret J C. 2012. Surfactants in droplet-based microfluidics. Lab on a Chip, 12: 422-433.
[27]	Baroud C N, Delville J-P, Gallaire F, Wunenburger R. 2007. Thermocapillary valve for droplet production and sorting. Physical Review E, 75: 046302.
[28]	Baroud C N, Gallaire F, Dangla R. 2010. Dynamics of microfluidic droplets. Lab on a Chip, 10: 2032-2045.
[29]	Bartlett J M, Stirling D. 2003. A short history of the polymerase chain reaction. In: PCR Protocols,Springer: 3-6.
[30]	Berthier J. 2013. Chapter 1 -Introduction: digital microfluidics in today's microfluidics. Micro-Drops and Digital Microfluidics(Second Edition). 1-6. J. Berthier, William Andrew Publishing
[31]	Bibette J, Calderon F L, Poulin P. 1999. Emulsions: basic principles. Reports on Progress in Physics, 62: 969.
[32]	Bremond N, Thiam A R, Bibette J. 2008. Decompressing emulsion droplets favors coalescence. Physical Review Letters, 100: 024501.
[33]	Casavant B P, Berthier E, Theberge A B, Berthier J, Montanez-Sauri S I, Bischel L L, Brakke K, Hedman C J, Bushman W, Keller N P. 2013. Suspended microfluidics. Proceedings of the National Academy of Sciences, 110: 10111-10116.
[34]	Ceniceros H D, Roma A M, Silveira-Neto A, Villar MM. 2010. A robust, fully adaptive hybrid level-set/front-tracking method for two-phase flows with an accurate surface tension computation. Communications in Computational Physics, 8: 51-94.
[35]	Chabert M, Dorfman K D, Viovy J L. 2005. Droplet fusion by alternating current (AC) field electrocoales-cence in microchannels. Electrophoresis, 26: 3706-3715.
[36]	Chabert M, Viovy J-L. 2008. Microfluidic high-throughput encapsulation and hydrodynamic self-sorting of single cells. Proceedings of the National Academy of Sciences, 105: 3191-3196.
[37]	Chen J, Li J, Sun Y. 2012. Microfluidic approaches for cancer cell detection, characterization, and separation.Lab on a Chip, 12: 1753-1767.
[38]	Chen X, Ma D, Yang V, Popinet S. 2013. High-fidelity simulations of impinging jet atomization. Atomization and Sprays, 23: 1079-1101.
[39]	Chen X, Yang V. 2014. Thickness-based adaptive mesh refinement methods for multi-phase flow simulations with thin regions. Journal of Computational Physics, 269: 22-39.
[40]	Choi C H, Jung J H, Hwang T S, Lee C S. 2009. In situ microfluidic synthesis of monodisperse PEG microspheres. Macromolecular Research, 17: 163-167.
[41]	Choi C H, Yi H, Hwang S, Weitz D A, Lee C S. 2011. Microfluidic fabrication of complex-shaped microfibers by liquid template-aided multiphase microflow. Lab on a Chip, 11: 1477-1483.
[42]	Choi C H, Kim J, Nam J O, Kang S M, Jeong S G, Lee C S. 2014. Microfluidic design of complex emulsions.Chem. Phys. Chem., 15: 21-29.
[43]	Christopher G, Anna S. 2007. Microfluidic methods for generating continuous droplet streams. Journal of Physics D: Applied Physics, 40: R319.
[44]	Christopher G, Bergstein J, End N, Poon M, Nguyen C, Anna S L. 2009. Coalescence and splitting of confined droplets at microfluidic junctions. Lab on a Chip, 9: 1102-1109.
[45]	Christopher G F, Noharuddin N N, Taylor J A, Anna S L. 2008. Experimental observations of the squeezing-to-dripping transition in T-shaped microfluidic junctions. Physical Review E, 78: 036317.
[46]	Chu L Y, Utada A S, Shah R K, Kim J W, Weitz D A. 2007. Controllable monodisperse multiple emulsions. Angewandte Chemie International Edition, 46: 8970-8974.
[47]	Clausell-Tormos J, Lieber D, Baret J-C, El-Harrak A, Miller O J, Frenz L, Blouwolff J, Humphry K J, Köster S, Duan H. 2008. Droplet-based microfluidic platforms for the encapsulation and screening of mammalian cells and multicellular organisms. Chemistry and Biology, 15: 427-437.
[48]	Cohen D E, Schneider T, Wang M, Chiu D T. 2010. Self-digitization of sample volumes. Analytical Chem-istry, 82: 5707-5717.
[49]	Cordero M L, Rolfsnes H O, Burnham D R, Campbell P A, Mcgloin D, Baroud C N. 2009. Mixing via thermocapillary generation of flow patterns inside a microfluidic drop. New Journal of Physics, 11: 075033.
[50]	Cramer C, Fischer P, Windhab E J. 2004. Drop formation in a co-flowing ambient fluid. Chemical Engi-neering Science, 59: 3045-3058.
[51]	Cristofanilli M, Hayes D F, Budd G T, Ellis M J, Stopeck A, Reuben J M, Doyle G V, Matera J, Allard W J, Miller M C. 2005. Circulating tumor cells: a novel prognostic factor for newly diagnosed metastatic breast cancer. Journal of Clinical Oncology, 23: 1420-1430.
[52]	Cubaud T, Mason T G. 2008. Capillary threads and viscous droplets in square microchannels. Physics of Fluids, 20: 053302.
[53]	Cui H-H, Silber-Li Z-H, Zhu S-N. 2004. Flow characteristics of liquids in microtubes driven by a high pressure. Physics of Fluids, 16: 1803-1810.
[54]	Dai B, Leal L G. 2008. The mechanism of surfactant effects on drop coalescence. Physics of Fluids, 20: 040802.
[55]	Datta S S, Abbaspourrad A, Amstad E, Fan J, Kim S H, Romanowsky M, Shum H C, Sun B, Utada A S, Windbergs M. 2014. 25th Anniversary article: Double emulsion templated solid microcapsules: Mechanics and controlled release. Advanced Materials, 26: 2205-2218.
[56]	De Menech M. 2006. Modeling of droplet breakup in a microfluidic T-shaped junction with a phase-field model. Physical Review E, 73: 031505.
[57]	De Menech M, Garstecki P, Jousse F, Stone H. 2008. Transition from squeezing to dripping in a microfluidic T-shaped junction. Journal of Fluid Mechanics, 595: 141-161.
[58]	Di Carlo D. 2009. Inertial microfluidics. Lab on a Chip, 9: 3038-3046.
[59]	Ding H, Spelt P D, Shu C. 2007. Diffuse interface model for incompressible two-phase flows with large density ratios. Journal of Computational Physics, 226: 2078-2095.
[60]	Diwakar S, Das S K, Sundararajan T. 2009. A quadratic spline based interface(QUASI) reconstruction algorithm for accurate tracking of two-phase flows. Journal of Computational Physics, 228: 9107-9130.
[61]	Dreyfus R, Tabeling P, Willaime H. 2003. Ordered and disordered patterns in two-phase flows in microchan-nels. Physical Review Letters, 90: 144505.
[62]	Edd J F, Di Carlo D, Humphry K J, Köster S, Irimia D,Weitz D A, Toner M. 2008. Controlled encapsulation of single-cells into monodisperse picolitre drops. Lab on a Chip, 8: 1262-1264.
[63]	Edgar J S, Milne G, Zhao Y, Pabbati C P, Lim D S, Chiu D T. 2009. Compartmentalization of chemically separated components into droplets. Angewandte Chemie International Edition, 48: 2719-2722.
[64]	Eggleton C D, Tsai T-M, Stebe K J. 2001. Tip streaming from a drop in the presence of surfactants. Physical Review Letters, 87: 048302.
[65]	Erni P, Windhab E J, Gunde R, Graber M, Pfister B, Parker A, Fischer P. 2007. Interfacial rheology of surface-active biopolymers: Acacia senegal gum versus hydrophobically modifed starch. Biomacro-molecules, 8: 3458-3466.
[66]	Erni P, Cramer C, Marti I, Windhab E J, Fischer P. 2009. Continuous flow structuring of anisotropic biopolymer particles. Advances in Colloid and Interface Science, 150: 16-26.
[67]	Fair R B. 2007. Digital microfluidics: is a true lab-on-a-chip possible? Microfluidics and Nanofluidics, 3: 245-281.
[68]	Fidalgo L, Abell C, Huck W. 2007. Surface-induced droplet fusion in microfluidic devices. Lab on a Chip, 7: 984.
[69]	Franke T, Abate A R, Weitz D A, Wixforth A. 2009. Surface acoustic wave (SAW) directed droplet flow in microfluidics for PDMS devices. Lab on a Chip, 9: 2625-2627.
[70]	Freytag T, Dashevsky A, Tillman L, Hardee G, Bodmeier R. 2000. Improvement of the encapsulation effciency of oligonucleotide-containing biodegradable microspheres. Journal of Controlled Release, 69: 197-207.
[71]	Funfschilling D, Debas H, Li H Z, Mason T G. 2009. Flow-field dynamics during droplet formation by dripping in hydrodynamic-focusing microfluidics. Physical Review E, 80: 015301.
[72]	GÜnther A, Khan S A, Thalmann M, Trachsel F, Jensen K F. 2004. Transport and reaction in microscale segmented gas-liquid flow. Lab on a Chip, 4: 278-286.
[73]	Gañán-Calvo A M. 1998. Generation of steady liquid microthreads and micron-sized monodisperse sprays in gas streams. Physical Review Letters, 80: 285.
[74]	Gad-El-Hak M. 1999. The fluid mechanics of microdevices\|the Freeman scholar lecture. Journal of Fluids Engineering, 121: 5-33.
[75]	Garstecki P, Stone H A, Whitesides G M. 2005. Mechanism for flow-rate controlled breakup in confined geometries: A route to monodisperse emulsions. Physical Review Letters, 94: 164501. Garstecki P, Fuerstman M J, Stone H A, Whitesides G M. 2006. Formation of droplets and bubbles in a microfluidic T-junction\|scaling and mechanism of break-up. Lab on a Chip, 6: 437-446.
[76]	Ginzburg I, Wittum G. 2001. Two-phase flows on interface refined grids modeled with VOF, staggered finite volumes, and spline interpolants. Journal of Computational Physics, 166: 302-335.
[77]	Glawdel T, Elbuken C, Ren C L. 2012a. Droplet formation in microfluidic T-junction generators operating in the transitional regime. II. Modeling. Physical Review E, 85: 016323.
[78]	Glawdel T, Elbuken C, Ren C L. 2012b. Droplet formation in microfluidic T-junction generators operating in the transitional regime. I. Experimental observations. Physical Review E, 85: 016322.
[79]	Greaves D. 2004. A quadtree adaptive method for simulating fluid flows with moving interfaces. Journal of Computational Physics, 194: 35-56.
[80]	Groβ S, Reichelt V, Reusken A. 2006. A finite element based level set method for two-phase incompressible flows. Computing and Visualization in Science, 9: 239-257.
[81]	Gu H, Malloggi F, Vanapalli S A, Mugele F. 2008. Electrowetting-enhanced microfluidic device for drop generation. Applied Physics Letters, 93: 183507.
[82]	Guillot P, Colin A, Utada A S, Ajdari A. 2007. Stability of a jet in confined pressure-driven biphasic flows at low Reynolds numbers. Physical Review Letters, 99: 104502.
[83]	Guillot P, Colin A, Ajdari A. 2008. Stability of a jet in confined pressure-driven biphasic flows at low Reynolds number in various geometries. Physical Review E, 78: 016307.
[84]	Gunstensen A K, Rothman D H, Zaleski S, Zanetti G. 1991. Lattice Boltzmann model of immiscible fluids.Physical Review A, 43: 4320-4327.
[85]	Gupta A, Kumar R. 2010. Effect of geometry on droplet formation in the squeezing regime in a microfluidic T-junction. Microfluidics and Nanofluidics, 8: 799-812.
[86]	Harlow F H, Welch J E. 1965. Numerical calculation of time-dependent viscous incompressible flow of fluid with free surface. Physics of Fluids, 8: 2182.
[87]	Hartmann D, Meinke M, Schröder W. 2008. Differential equation based constrained reinitialization for level set methods. Journal of Computational Physics, 227: 6821-6845.
[88]	Hartmann D, Meinke M, Schröder W. 2010. The constrained reinitialization equation for level set methods.Journal of Computational Physics, 229: 1514-1535.
[89]	Hasinovic H, Friberg S E. 2011. One-step inversion process to a Janus emulsion with two mutually insoluble oils. Langmuir, 27: 6584-6588.
[90]	Hatch A C, Patel A, Beer N R, Lee A P. 2013. Passive droplet sorting using viscoelastic flow focusing. Lab on a Chip, 13: 1308-1315.
[91]	Hirt C, Amsden A A, Cook J. 1974. An arbitrary Lagrangian-Eulerian computing method for all flow speeds.Journal of Computational Physics, 14: 227-253.
[92]	Hirt C W, Nichols B D. 1981. Volume of fluid (VOF) method for the dynamics of free boundaries. Journal of Computational Physics, 39: 201-225.
[93]	Ho B, Leal L. 1974. Inertial migration of rigid spheres in two-dimensional unidirectional flows. Journal of Fluid Mechanics, 65: 365-400.
[94]	Hoang D, Portela L, Kleijn C, Kreutzer M, Van Steijn V. 2013. Dynamics of droplet breakup in a T-junction. Journal of Fluid Mechanics, 717: R4.
[95]	Hogg A J. 1994. The inertial migration of non-neutrally buoyant spherical particles in two-dimensional shear flows. Journal of Fluid Mechanics, 272: 285-318.
[96]	Holtze C, Rowat A, Agresti J, Hutchison J, Angile F, Schmitz C, Köster S, Duan H, Humphry K, Scanga R. 2008. Biocompatible surfactants for water-in-fluorocarbon emulsions. Lab on a Chip, 8: 1632-1639.Hu H H, Patankar N A, Zhu M. 2001. Direct numerical simulations of fluid{solid systems using the arbitrary Lagrangian{Eulerian technique. Journal of Computational Physics, 169: 427-462.
[97]	Huebner A, Srisa-Art M, Holt D, Abell C, Hollfelder F, Edel J. 2007. Quantitative detection of protein expression in single cells using droplet microfluidics. Chemical Communications, 12: 1218-1220.
[98]	Huebner A, Bratton D, Whyte G, Yang M, Abell C, Hollfelder F. 2009. Static microdroplet arrays: a microfluidic device for droplet trapping, incubation and release for enzymatic and cell-based assays. Lab on a Chip, 9: 692-698.
[99]	Huerre P, Monkewitz P A. 1990. Local and global instabilities in spatially developing flows. Annual Review of Fluid Mechanics, 22: 473-537.
[100]	Humphry K J, Ajdari A, Fernández-Nieves A, Stone H A, Weitz D A. 2009. Suppression of instabilities in multiphase flow by geometric confinement. Physical Review E, 79: 056310.
[101]	Hur S C, Henderson-Maclennan N K, Mccabe E R, Di Carlo D. 2011. Deformability-based cell classification and enrichment using inertial microfluidics. Lab on a Chip, 11: 912-920.
[102]	I Solvas X. 2011. Droplet microfluidics: recent developments and future applications. Chemical Communi-cations, 47: 1936-1942.
[103]	Jensen M J. 2002. Bubbles in microchannels. Master project, Denmark: MIC{Technical University of Denmark.
[104]	Jeong W J, Kim J Y, Choo J, Lee E K, Han C S, Beebe D J, Seong G H, Lee S H. 2005. Continuous fabrication of biocatalyst immobilized microparticles using photopolymerization and immiscible liquids in microfluidic systems. Langmuir, 21: 3738-3741.
[105]	Joensson H N, Andersson Svahn H. 2012. Droplet microfluidics-a tool for single-cell analysis. Angewandte Chemie International Edition, 51: 12176-12192.
[106]	Kadam S T, Kumar R. 2014. Twenty first century cooling solution: Microchannel heat sinks. International Journal of Thermal Sciences, 85: 73-92.
[107]	Kantak C, Zhu Q, Beyer S, Bansal T, Trau D. 2012. Utilizing microfluidics to synthesize polyethylene glycol microbeads for Förster resonance energy transfer based glucose sensing. Biomicrofluidics, 6: 022006.
[108]	Karimi A, Yazdi S, Ardekani A. 2013. Hydrodynamic mechanisms of cell and particle trapping in microflu-idics. Biomicrofluidics, 7: 021501.
[109]	Khodaparast S, Borhani N, Thome J. 2014. Application of micro particle shadow velocimetry PSV to two-phase flows in microchannels. International Journal of Multiphase Flow, 62: 123-133.
[110]	Kim H, Luo D, Link D, Weitz D A, Marquez M, Cheng Z. 2007. Controlled production of emulsion drops using an electric field in a flow-focusing microfluidic device. Applied Physics Letters, 91: 133106.
[111]	Kim S H, Weitz D A. 2011. One-step emulsification of multiple concentric shells with capillary microfluidic devices. Angewandte Chemie, 123: 8890-8893.
[112]	Kim Y W, Yoo J Y. 2012. Transport of solid particles in microfluidic channels. Optics and Lasers in Engineering, 50: 87-98.
[113]	Kinoshita H, Kaneda S, Fujii T, Oshima M. 2007. Three-dimensional measurement and visualization of internal flow of a moving droplet using confocal micro-PIV. Lab on a Chip, 7: 338-346.
[114]	Ko H, Liu C, Gau C, Jeng D. 2008. Flow characteristics in a microchannel system integrated with arrays of micro-pressure sensors using a polymer material. Journal of Micromechanics and Microengineering, 18:075016.
[115]	Lagus T P, Edd J F. 2013a. High-throughput co-encapsulation of self-ordered cell trains: Cell pair interac-tions in microdroplets. RSC Advances, 3: 20512-20522.
[116]	Lagus T P, Edd J F. 2013b. A review of the theory, methods and recent applications of high-throughput single-cell droplet microfluidics. Journal of Physics D: Applied Physics, 46: 114005.
[117]	Lee B, Yoo J Y. 2011. Droplet bistability and its application to droplet control. Microfluidics and Nanoflu-idics, 11: 685-693.
[118]	Li L, Du W, Ismagilov R F. 2010. Multiparameter screening on slip chip used for nanoliter protein crystal-lization combining free interface diffusion and microbatch methods. J. Am. Chem . Soc., 132: 112-119.
[119]	Li X B, Li F C, Yang J C, Kinoshita H, Oishi M, Oshima M. 2012. Study on the mechanism of droplet formation in T-junction microchannel. Chemical Engineering Science, 69: 340-351.
[120]	Liau A, Karnik R, Majumdar A, Cate J H D. 2005. Mixing crowded biological solutions in milliseconds. Analytical Chemistry, 77: 7618-7625.
[121]	Link D, Anna S L, Weitz D, Stone H. 2004. Geometrically mediated breakup of drops in microfluidic devices. Physical Review Letters, 92: 054503.
[122]	Liu H, Zhang Y. 2011. Droplet formation in microfluidic cross-junctions. Physics of Fluids, 23: 082101.
[123]	Lundgaard L, Berg G, Ingebrigsten S, Atten P. 2006. Electrocoalescence for oil-water separation: Funda-mental aspects. In: Emulsions and Emulsion Stability, CRC Press. 549-592.
[124]	Maddala J, Wang W S, Vanapalli S A, Rengaswamy R. 2013. Tra±c of pairs of drops in microfluidic ladder networks with fore-aft structural asymmetry. Microfluidics and Nanofluidics, 14: 337-344.
[125]	Mai D J, Brockman C, Schroeder C M. 2012. Microfluidic systems for single DNA dynamics. Soft Matter, 8: 10560-10572.
[126]	Malik M, Fan E S C, Bussmann M. 2007. Adaptive VOF with curvature-based refinement. International Journal for Numerical Methods in Fluids, 55: 693-712.
[127]	Manz A, Graber N, Widmer H. 1990. Miniaturized total chemical analysis systems: A novel concept for chemical sensing. Sensors and Actuators B: Chemical, 1: 244-248.
[128]	Marti I, Höfler O, Fischer P, Windhab E J. 2005. Rheology of concentrated suspensions containing mixtures of spheres and fibres. Rheologica Acta, 44: 502-512.
[129]	Matas J-P, Morris J F, Guazzelli 2009. Lateral force on a rigid sphere in large-inertia laminar pipe flow. Journal of Fluid Mechanics, 621: 59.
[130]	Mazutis L, Baret J-C, Gri±ths A D. 2009. A fast and e±cient microfluidic system for highly selective one-to-one droplet fusion. Lab on a Chip, 9: 2665-2672.
[131]	Mazutis L, Gri±ths A D. 2012. Selective droplet coalescence using microfluidic systems. Lab on a Chip, 12: 1800-1806.
[132]	Meinhart C D, Wereley S T, Santiago J G. 1999. PIV measurements of a microchannel flow. Experiments in Fluids, 27: 414-419.
[133]	Migler K B. 2001. String formation in sheared polymer blends: coalescence, breakup, and finite size effects.Physical Review Letters, 86: 1023.
[134]	Morini G, Spiga M, Tartarini P. 1998. Laminar viscous dissipation in rectangular ducts. International Communications in Heat and Mass Transfer, 25: 551-560.
[135]	Mullis K, Faloona F, Scharf S, Saiki R, Horn G, Erlich H. 1992. Specific enzymatic amplification of DNA in vitro: The polymerase chain reaction. Biotechnology Series, 51: 263-273.
[136]	Nakano M. 2000. Places of emulsions in drug delivery. Advanced Drug Delivery Reviews, 45: 1-4.
[137]	Nie J, Kennedy R T. 2010. Sampling from nanoliter plugs via asymmetrical splitting of segmented flow. Analytical Chemistry, 82: 7852-7856.
[138]	Nisar A, Aftuipurkar N, Mahaisavariya B, Tuantranont A. 2008. MEMS-based micropumps in drug delivery and biomedical applications. Sensors and Actuators B, 130: 917-942.
[139]	Niu X, Gulati S, Edel J B. 2008. Pillar-induced droplet merging in microfluidic circuits. Lab on a Chip, 8: 1837-1841.
[140]	Nobari M, Jan Y J, Tryggvason G. 1996. Head-on collision of drops\|a numerical investigation. Physics of Fluids, 8: 29-42.
[141]	Nochetto R H, Walker S W. 2010. A hybrid variational front tracking-level set mesh generator for problems exhibiting large deformations and topological changes. Journal of Computational Physics, 229: 6243-6269.
[142]	Noh W F, Woodward P. 1976. SLIC (simple line interface calculation). In: Proceedings of the Fifth Inter-national Conference on Numerical Methods in Fluid Dynamics, June 28-July 2, 1976, Twente University, Enschede, Springer.
[143]	Nourgaliev R R, Dinh T N, Theofanous T G, Joseph D. 2003. The Lattice Boltzmann equation method: theoretical interpretation, numerics and implications. International Journal of Multiphase Flow, 29: 117-169.
[144]	Nunes J, Tsai S, Wan J, Stone H. 2013. Dripping and jetting in microfluidic multiphase flows applied to particle and fibre synthesis. Journal of Physics D: Applied Physics, 46: 114002.
[145]	Ogończyk D, Siek M, Garstecki P. 2011. Microfluidic formulation of pectin microbeads for encapsulation and controlled release of nanoparticles. Biomicrofluidics, 5: 013405.
[146]	Okushima S, Nisisako T, Torii T, Higuchi T. 2004. Controlled production of monodisperse double emulsions by two-step droplet breakup in microfluidic devices. Langmuir, 20: 9905-9908.
[147]	Olsson E, Kreiss G. 2005. A conservative level set method for two phase flow. Journal of Computational Physics, 210: 225-246.
[148]	Osher S, Sethian J A. 1988. Fronts propagating with curvature-dependent speed: algorithms based on Hamilton-Jacobi formulations. Journal of Computational Physics, 79: 12-49.
[149]	Park J S, Kihm K D. 2006. Use of confocal laser scanning microscopy(CLSM) for depthwise resolved microscale-particle image velocimetry (μ-PIV). Optics and Lasers in Engineering, 44: 208-223.
[150]	Pekin D, Skhiri Y, Baret J C, Le Corre D, Mazutis L, Salem C B, Millot F, El Harrak A, Hutchison J B, Larson J W. 2011. Quantitative and sensitive detection of rare mutations using droplet-based microfluidics. Lab on a Chip, 11: 2156-2166.
[151]	Popinet S. 2009. An accurate adaptive solver for surface-tension-driven interfacial flows. Journal of Com-putational Physics, 228: 5838-5866.
[152]	Prakash M, Gershenfeld N. 2007. Microfluidic bubble logic. Science, 315: 832-835.
[153]	Priest C, Herminghaus S, Seemann R. 2006. Controlled electrocoalescence in microfluidics: Targeting a single lamella. Applied Physics Letters, 89: 134101.
[154]	Probstein R. 1994. Physicochemical Hydrodynamics: An Introduction, New York: Wiley and Sons.Quan S, Schmidt D P. 2007. A moving mesh interface tracking method for 3D incompressible two-phase flows. Journal of Computational Physics, 221: 761-780.
[155]	Quan S, Lou J, Schmidt D P. 2009. Modeling merging and breakup in the moving mesh interface tracking method for multiphase flow simulations. Journal of Computational Physics, 228: 2660-2675.
[156]	Quan S. 2011. Simulations of multiphase flows with multiple length scales using moving mesh interface tracking with adaptive meshing. Journal of Computational Physics, 230: 5430-5448.
[157]	Renardy Y, Renardy M. 2002. PROST: A parabolic reconstruction of surface tension for the volume-of-fluid method. Journal of Computational Physics, 183: 400-421.
[158]	Romanowsky M B, Abate A R, Rotem A, Holtze C, Weitz D A. 2012. High throughput production of single core double emulsions in a parallelized microfluidic device. Lab on a Chip, 12: 802-807.
[159]	Rubinow S, Keller J B. 1961. The transverse force on a spinning sphere moving in a viscous fluid. Journal of Fluid Mechanics, 11: 447-459.
[160]	Rudman M. 1997. Volume-tracking methods for interfacial flow calculations. International Journal for Numerical Methods in Fluids, 24: 671-691.
[161]	Saffman P. 1965. The lift on a small sphere in a slow shear flow. Journal of Fluid Mechanics, 22: 385-400.
[162]	Santiago J G, Wereley S T, Meinhart C D, Beebe D, Adrian R J. 1998. A particle image velocimetry system for microfluidics. Experiments in Fluids, 25: 316-319.
[163]	Sarrazin F, Prat L, Di Miceli N, Cristobal G, Link D, Weitz D. 2007. Mixing characterization inside microdroplets engineered on a microcoalescer. Chemical Engineering Science, 62: 1042-1048.
[164]	Schaerli Y, Wootton R C, Robinson T, Stein V, Dunsby C, Neil M A, French P M, Demello A J, Abell C, Hollfelder F. 2008. Continuous-flow polymerase chain reaction of single-copy DNA in microdroplets. Analytical Chemistry, 81: 302-306.microfluidic
[165]	Schmid L, Franke T. 2013. SAW-controlled drop size for flow focusing. Lab on a Chip, 13: 1691-1694.
[166]	Schmitz C H, Rowat A C, Köster S, Weitz D A. 2009. Dropspots: a picoliter array in a microfluidic device. Lab on a Chip, 9: 44-49.
[167]	Schneider T, Kreutz J, Chiu D T. 2013. The potential impact of droplet microfluidics in biology. Analytical Chemistry, 85: 3476-3482.
[168]	Schonberg J A, Hinch E. 1989. Inertial migration of a sphere in Poiseuille flow. Journal of Fluid Mechanics, 203: 517-524.
[169]	Seemann R, Brinkmann M, Pfohl T, Herminghaus S. 2012. Droplet based microfluidics. Reports on Progress in Physics, 75: 016601.
[170]	Segré G, Silberberg A. 1961. Radial particle displacements in poiseuille flow of suspensions. Nature, 189: 209-210.
[171]	Segré G, Silberberg A. 1962. Behaviour of macroscopic rigid spheres in Poiseuille flow Part 2. Experimental results and interpretation. Journal of Fluid Mechanics, 14: 136-157.
[172]	Seo M, Paquet C, Nie Z, Xu S, Kumacheva E. 2007. Microfluidic consecutive flow-focusing droplet generators. Soft Matter, 3: 986-992.
[173]	Seppecher P. 1996. Moving contact lines in the Cahn-Hilliard theory. International Journal of Engineering Science, 34: 977-992.
[174]	Sethian J, Smereka P. 2003. Level set methods for fluid interfaces. Annual Review of Fluid Mechanics, 35: 341-372.
[175]	Shan X, Chen H. 1993. Lattice Boltzmann model for simulating flows with multiple phases and components. Physical Review E, 47: 1815-1819.
[176]	Shi W, Qin J, Ye N, Lin B. 2008. Droplet-based microfluidic system for individual Caenorhabditis elegans assay. Lab on a Chip, 8: 1432-1435.
[177]	Shi W, Wen H, Lu Y, Shi Y, Lin B, Qin J. 2010. Droplet microfluidics for characterizing the neurotoxin-induced responses in individual Caenorhabditis elegans. Lab on a Chip, 10: 2855-2863.
[178]	Shim J-U, Cristobal G, Link D R, Thorsen T, Jia Y, Piattelli K, Fraden S. 2007a. Control and measurement of the phase behavior of aqueous solutions using microfluidics. Journal of the American Chemical Society, 129: 8825-8835.
[179]	Shim J U, Cristobal G, Link D R, Thorsen T, Jia Y, Piattelli K, Fraden S. 2007b. Control and measurement of the phase behavior of aqueous solutions using microfluidics. Journal of the American Chemical Society, 129: 8825-8835.
[180]	Shim J U, Olguin L F, Whyte G, Scott D, Babtie A, Abell C, Huck W T, Hollfelder F. 2009. Simultaneous determination of gene expression and enzymatic activity in individual bacterial cells in microdroplet compartments. Journal of the American Chemical Society, 131: 15251-15256.
[181]	Shin S, Juric D. 2009. A hybrid interface method for three-dimensional multiphase flows based on front tracking and level set techniques. International Journal for Numerical Methods in Fluids, 60: 753-778.
[182]	Sivasamy J, Wong T-N, Nguyen N-T, Kao L T-H. 2011. An investigation on the mechanism of droplet formation in a microfluidic T-junction. Microfluidics and Nanofluidics, 11: 1-10.
[183]	Song H, Bringer M R, Tice J D, Gerdts C J, Ismagilov R F. 2003a. Experimental test of scaling of mixing by chaotic advection in droplets moving through microfluidic channels. Applied Physics Letters, 83: 4664-4666.