Controllable production of Janus ligaments by AC fields in a flow-focusing junction

  • Elena Castro-HernándezEmail author
  • Pablo García-Sánchez
  • Marta León-Rodríguez
  • David Fernandez Rivas
  • Antonio Ramos
Short Communication


We report the production of bicomponent Janus filaments of miscible aqueous fluids in a microfluidic electro-flow-focusing device under the action of an AC electric field. The production of liquid filaments can lead to the generation of microfibers by adding a subsequent process of polymerization. Janus microfibers are of paramount importance in biomedical applications such as tissue production on crimped scaffolds. We show that the filament length is a function of the frequency signal, voltage amplitude and of the viscosity and conductivity of the dispersed phase. In particular, Janus filaments with diameters \(\sim 10\,\upmu\)m and longer than 1 mm are produced by AC voltages with frequencies below 150 kHz and a viscosity of the dispersed phase \(\sim 10\,\) cP.


AC electric field Flow focusing Microfluidics Janus 



The authors would like to acknowledge financial support from Spanish Government Ministry MEC under Contracts DPI2016-78887-C3-1-R and FIS2014-54539-P. They would also like to acknowledge the technical assistance of S. Schlautman in the fabrication of the microfluidic devices.


  1. Anna SL, Bontoux N, Stone HA (2003) Formation of dispersions using Flow Focusing in microchannels. Appl Phys Lett 82:364–366CrossRefGoogle Scholar
  2. Buschle-Diller G, Cooper J, Xie Z, Wu Y, Waldrup J, Ren X (2007) Release of antibiotics from electrospun bicomponent fibers. Cellulose 14(6):553–562CrossRefGoogle Scholar
  3. Castro-Hernández E, Campo-Cortés F, Gordillo JM (2012) Slender-body theory for the generation of micrometre-sized emulsions through tip streaming. J Fluid Mech 698:423–445CrossRefGoogle Scholar
  4. Castro-Hernández E, García-Sánchez P, Tan SH, Gañán-Calvo AM, Baret JC, Ramos A (2015) Breakup length of ac electrified jets in a microfluidic flow-focusing junction. Microfluid Nanofluid 19(4):787–794CrossRefGoogle Scholar
  5. Castro-Hernández E, García-Sánchez P, Alzaga-Gimeno J, Tan SH, Baret JC, Ramos A (2016) Ac electrified jets in a flow-focusing device: jet length scaling. Biomicrofluidics 10(4):043–504CrossRefGoogle Scholar
  6. Castro-Hernández E, García-Sánchez P, Velencoso-Gómez A, Silas-Jurado A, Rivas DF, Ramos A (2017) Droplet group production in an ac electro-flow-focusing microdevice. Microfluid Nanofluid 21(10):158CrossRefGoogle Scholar
  7. Chen F, Hayami JW, Amsden BG (2014) Electrospun poly (l-lactide-co-acryloyl carbonate) fiber scaffolds with a mechanically stable crimp structure for ligament tissue engineering. Biomacromolecules 15(5):1593–1601CrossRefGoogle Scholar
  8. Chen G, Xu Y, Yu DG, Zhang DF, Chatterton NP, White KN (2015) Structure-tunable janus fibers fabricated using spinnerets with varying port angles. Chem Commun 51(22):4623–4626CrossRefGoogle Scholar
  9. Gañán-Calvo AM (1998) Generation of steady liquid microthreads and micron-sized monodisperse sprays in gas streams. Phys Rev Lett 80(2):285CrossRefGoogle Scholar
  10. Gañán-Calvo AM (2006) Jetting-dripping transition of a liquid jet in a lower viscosity co-flowing immiscible liquid: the minimum flow rate in flow focusing. J Fluid Mech 553:75–84CrossRefGoogle Scholar
  11. Guillot P, Colin A, Utada AS, Ajdari A (2007) Stability of a jet in confined pressure-driven biphasic flows at low Reynolds numbers. Phys Rev Lett 99(104):502Google Scholar
  12. Guillot P, Colin A, Ajdari A (2008) Stability of a jet in confined pressure-driven biphasic flows at low Reynolds number in various geometries. Phys Rev E 78(016):307Google Scholar
  13. Gupta P, Wilkes GL (2003) Some investigations on the fiber formation by utilizing a side-by-side bicomponent electrospinning approach. Polymer 44(20):6353–6359CrossRefGoogle Scholar
  14. Kang DW, Ko W, Lee B, Park BJ (2016) Effect of geometric and chemical anisotropy of janus ellipsoids on janus boundary mismatch at the fluid-fluid interface. Materials 9(8):664CrossRefGoogle Scholar
  15. Kim H, Luo D, Link D, Weitz DA, Marquez M, Cheng Z (2007) Controlled production of emulsion drops using an electric field in a flow-focusing microfluidic device. Appl Phys Lett 91(13):133–106Google Scholar
  16. Liu J, Liu G, Zhang M, Sun P, Zhao H (2013) Synthesis and self-assembly of amphiphilic janus laponite disks. Macromolecules 46(15):5974–5984CrossRefGoogle Scholar
  17. Liu Y, Liang F, Wang Q, Qu X, Yang Z (2015) Flexible responsive janus nanosheets. Chem Commun 51(17):3562–3565CrossRefGoogle Scholar
  18. Nisisako T (2016) Recent advances in microfluidic production of janus droplets and particles. Curr Opin Colloid Interface Sci 25:1–12CrossRefGoogle Scholar
  19. Pérez-Rigueiro J, Madurga R, Gañán-Calvo A, Plaza G, Elices M, López P, Daza R, González-Nieto D, Guinea G (2018) Straining flow spinning of artificial silk fibers: A review. Biomimetics 3(4):29CrossRefGoogle Scholar
  20. Perro A, Reculusa S, Ravaine S, Bourgeat-Lami E, Duguet E (2005) Design and synthesis of janus micro-and nanoparticles. J Mater Chem 15(35–36):3745–3760CrossRefGoogle Scholar
  21. Siegel AC, Shevkoplyas SS, Weibel DB, Bruzewicz DA, Martinez AW, Whitesides GM (2006) Cofabrication of electromagnets and microfluidic systems in poly(dimethylsiloxane). Angew Chem 118:7031–7036CrossRefGoogle Scholar
  22. Sinzato YZ, Dias NJS, Cunha FR (2017) An experimental investigation of the interfacial tension between liquid-liquid mixtures in the presence of surfactants. Exp Thermal Fluid Sci 85:370–378CrossRefGoogle Scholar
  23. Starr JD, Andrew JS (2013) Janus-type bi-phasic functional nanofibers. Chem Commun 49(39):4151–4153CrossRefGoogle Scholar
  24. Starr JD, Budi MA, Andrew JS (2015) Processing-property relationships in electrospun janus-type biphasic ceramic nanofibers. J Am Ceram Soc 98(1):12–19CrossRefGoogle Scholar
  25. Surrao DC, Fan JC, Waldman SD, Amsden BG (2012) A crimp-like microarchitecture improves tissue production in fibrous ligament scaffolds in response to mechanical stimuli. Acta Biomater 8(10):3704–3713CrossRefGoogle Scholar
  26. Tan SH, Semin B, Baret JC (2014) Microfluidic flow-focusing in ac electric fields. Lab Chip 14(6):1099–1106CrossRefGoogle Scholar
  27. Utada AS, Fernández-Nieves A, Gordillo JM, Weitz D (2008) Absolute instability of a liquid jet in a coflowing stream. Phys Rev Lett 100(014):502Google Scholar
  28. Wu Q, Yang C, Yang J, Huang F, Liu G, Zhu Z, Si T, Xu RX (2018) Photopolymerization of complex emulsions with irregular shapes fabricated by multiplex coaxial flow focusing. Appl Phys Lett 112(7):071–601CrossRefGoogle Scholar
  29. Zhu P, Wang L (2017) Passive and active droplet generation with microfluidics: a review. Lab Chip Miniaturisation Chem Biol 17(1):34–75CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Área de Mecánica de Fluidos, Departamento de Ingeniería Aeroespacial y Mecánica de FluidosUniversidad de SevillaSevillaSpain
  2. 2.Departamento de Electrónica y Electromagnetismo, Facultad de FísicaUniversidad de SevillaSevillaSpain
  3. 3.Mesoscale Chemical Systems GroupEnschedeThe Netherlands

Personalised recommendations