Dynamics of capillary flow in an open superoleophilic microchannel and its application to sensing of oil

  • B. Majhy
  • R. Iqbal
  • R. Gaikwad
  • A. K. SenEmail author
Research Paper


We report the dynamics of capillary flow of oil in an open superoleophilic channel. The superoleophilic surface is fabricated by spin coating a layer of PDMS + n-hexane followed by candle sooting. The occurrence of various flow regimes, including the inertial, visco-inertial, and Lucas–Washburn regimes, are studied using analytical modelling as well as experiments. In case of a superoleophilic channel, much shorter inertial regime is observed as compared to that in an oleophilic channel due to the wicking of oil into the micro-roughness grooves ahead to moving bulk liquid meniscus. The study of the effect of channel aspect ratio \(\varepsilon\) on the mobility parameter \(k~\)showed that the mobility parameter \(k\) is maximum for an aspect ratio of \(\varepsilon =1.6\), which is attributed to the balance between the capillary and viscous forces. Finally, we demonstrate the application of the superoleophilic channel integrated with electrodes for impedance-based sensing of oil from an oil–water emulsion.



This work was supported by the Science and Engineering Research Board (SERB), Department of Science and Technology (DST), India, via Grant no. EMR/2014/001151 and IIT Madras via project no. MEE1516843RFTPASHS. The author would like to thank the NCCRD, IIT Madras for the measurements of viscosity and surface tension of the oil. The author would also like to thank Mr. N. Kumar for helping with the micro-milling operation.

Supplementary material

10404_2018_2139_MOESM1_ESM.docx (23 kb)
Supplementary material 1 (DOCX 22 KB)


  1. Anoop R, Sen AK (2015) Capillary flow enhancement in rectangular polymer microchannels with a deformable wall. Phys Rev E 92:0130241–0130246. MathSciNetCrossRefGoogle Scholar
  2. Ashraf MW, Tayyaba S, Afzulpurkar N (2011) Micro electromechanical systems (MEMS) based microfluidic devices for biomedical applications. Int J Mol Sci 12:3648–3704. CrossRefGoogle Scholar
  3. Bosanquet CH (1923) On the flow of liquids into capillary tubes. Philos Mag Ser 645:525–531. CrossRefGoogle Scholar
  4. Bouaidat S, Hansen O, Bruus H et al (2005) Surface-directed capillary system; theory, experiments and applications. Lab Chip. CrossRefGoogle Scholar
  5. Bouffard SP, Katon JE, Sommer AJ, Danielson ND (1994) Development of microchannel thin-layer chromatography with infrared microspectroscopic detection. Anal Chem 66:1937–1940. CrossRefGoogle Scholar
  6. Coney TA, Masica WJ (1969) Effect of flow rate on the dynamic contact angle for wetting liquids. NASA Technical NoteGoogle Scholar
  7. Delker T, Pengra DB, Wong P (1996) Interface pinning and the dynamics of capillary rise in porous media. Phys Rev Lett 76:2902–2905. CrossRefGoogle Scholar
  8. Di Carlo D, Irimia D, Tompkins RG, Toner M (2007) Continuous inertial focusing, ordering, and separation of particles in microchannels. Proc Natl Acad Sci USA 104:18892–18897. CrossRefGoogle Scholar
  9. Dummann G, Quittmann U, Groschel L et al (2003) The capillary-microreactor: a new reactor concept for the intensification of heat and mass transfer in liquid–liquid reactions. Catal Today 79–80:433–439. CrossRefGoogle Scholar
  10. Eral HB,’t Mannetje DJCM, Oh JM (2013) Contact angle hysteresis: a review of fundamentals and applications. Colloid Polym Sci 291:247–260. CrossRefGoogle Scholar
  11. Fries N, Dreyer M (2008) The transition from inertial to viscous flow in capillary rise. J Colloid Interface Sci 327:125–128. CrossRefGoogle Scholar
  12. Fuchiwaki Y, Tanaka M, Takaoka H, Goya K (2016) A capillary flow immunoassay microchip utilizing inkjet printing-based antibody immobilization onto island surfaces—toward sensitive and reproducible determination of carboxyterminal propeptide of type i procollagen. J Micromech Microeng. CrossRefGoogle Scholar
  13. Gennes P-G, de Brochard-Wyart F, Quere D (2004) Capillarity and wetting phenomena: drops, bubbles, pearls, waves. Springer, BerlinCrossRefGoogle Scholar
  14. George D, Anoop R, Sen AK (2015) Elastocapillary powered manipulation of liquid plug in microchannels. Appl Phys Lett 108:1. CrossRefGoogle Scholar
  15. Iqbal R, Majhy B, Sen AK (2017) Facile fabrication and characterization of a PDMS-derived candle soot coated stable biocompatible superhydrophobic and superhemophobic surface. ACS Appl Mater Interfaces. CrossRefGoogle Scholar
  16. Joanny JF, de Gennes PG (1984) A model for contact angle hysteresis. J Chem Phys 81:552–562. CrossRefGoogle Scholar
  17. Kim E, Xia Y, Whitesides GM (1996) Micromolding in capillaries: applications in materials science. J Am Chem Soc. CrossRefGoogle Scholar
  18. Lucas R (1918) Ueber das Zeitgesetz des kapillaren Aufstiegs von Flüssigkeiten. Kolloid-Zeitschrift 23:15–22. CrossRefGoogle Scholar
  19. Maria MS, Rakesh PE, Chandra TS, Sen AK (2016) Capillary flow of blood in a microchannel with differential wetting for blood plasma separation and on-chip glucose detection. Biomicrofluidics 10:054108. CrossRefGoogle Scholar
  20. Maria MS, Rakesh PE, Chandra TS, Sen AK (2017) Capillary flow-driven microfluidic device with wettability gradient and sedimentation effects for blood plasma separation. Sci Rep 7:43457. CrossRefGoogle Scholar
  21. Mullins BJ, Braddock RD (2012) Capillary rise in porous, fibrous media during liquid immersion. Int J Heat Mass Transf 55:6222–6230. CrossRefGoogle Scholar
  22. Ouali FF, McHale G, Javed H et al (2013) Wetting considerations in capillary rise and imbibition in closed square tubes and open rectangular cross-section channels. Microfluid Nanofluid. CrossRefGoogle Scholar
  23. Popescu MN, Ralston J, Sedev R (2008) Capillary rise with velocity-dependent dynamic contact angle. Langmuir 24:12710–12716. CrossRefGoogle Scholar
  24. Prothero J (1961) The physics of blood flow in capillaries. I. The nature of the motion. Biophys J 1:565–579. CrossRefGoogle Scholar
  25. Reddy SP, Samy A, Sen AK (2016) Interaction of elastocapillary flows in parallel microchannels across a thin membrane. Appl Phys Lett 109:141601. CrossRefGoogle Scholar
  26. Romero LA, Yost FG (1996) Flow in an open channel capillary. J Fluid Mech 322:109. CrossRefzbMATHGoogle Scholar
  27. Samy A, George D, Sen AK (2017) Bio-inspired liquid transport via elastocapillary interaction of a thin membrane with liquid meniscus. Soft Matter 13:6858. CrossRefGoogle Scholar
  28. Sanders JC, Huang Z, Landers JP (2001) Acousto-optical deflection-based whole channel scanning for microchip isoelectric focusing with laser-induced fluorescence detection. Lab Chip 1:167. CrossRefGoogle Scholar
  29. Shin S, Seo J, Han H et al (2016) Bio-inspired extreme wetting surfaces for biomedical applications. Materials (Basel) 9:116CrossRefGoogle Scholar
  30. Shirtcliffe NJ, McHale G, Newton MI et al (2006) Critical conditions for the wetting of soils. Appl Phys Lett. CrossRefGoogle Scholar
  31. Sorbie KS, Wu YZ, McDougall SR (1995) The extended washburn equation and its application to the oil/water pore doublet problem. J Colloid Interface Sci 174:289–301. CrossRefGoogle Scholar
  32. Sowers TW, Sarkar R, Eswarappa Prameela S et al (2016) Capillary driven flow of polydimethylsiloxane in open rectangular microchannels. Soft Matter 12:5818–5823. CrossRefGoogle Scholar
  33. Squires TM, Quake SR (2005) Microfluidics: fluid physics at the nanoliter scale. Rev Mod Phys 77:977CrossRefGoogle Scholar
  34. Washburn EW (1921) The dynamics of capillary flow. Phys Rev. CrossRefGoogle Scholar
  35. Weigl B, Domingo G, Labarre P, Gerlach J (2008) Towards non- and minimally instrumented, microfluidics-based diagnostic devices. Lab Chip 8:1999–2014. CrossRefGoogle Scholar
  36. Yang D, Krasowska M, Priest C, Ralston J (2014) Dynamics of capillary-driven liquid–liquid displacement in open microchannels. Phys Chem Chem Phys 16:24473–24478. CrossRefGoogle Scholar
  37. Yeo LY, Chang HC, Chan PPY, Friend JR (2011) Microfluidic devices for bioapplications. Small 7:12–48. CrossRefGoogle Scholar
  38. Yu T, Xiaoqian C, Yiyong H (2015) Capillary flow rate limitation in asymmetry open channel. CrossRefGoogle Scholar
  39. Zubair M, Tang TB (2014) A high resolution capacitive sensing system for the measurement of water content in crude oil. Sensors (Basel) 14:11351–11361. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringIndian Institute of Technology MadrasChennaiIndia

Personalised recommendations