대한기계학회논문집B (Transactions of the Korean Society of Mechanical Engineers B)

  • 제39권11호
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  • Pages.871-884
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  • 2015
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  • 1226-4881(pISSN)
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  • 2288-5324(eISSN)
대한기계학회 (The Korean Society of Mechanical Engineers)
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친수성/소수성 복합표면상에서 초기 구형 액적의 이송 메커니즘

Transport Mechanism of an Initially Spherical Droplet on a Combined Hydrophilic/Hydrophobic Surface

  • 명현국 (국민대학교 기계공학과) ;
  • 권영후 (국민대학교 기계공학과)
  • 투고 : 2015.06.09
  • 심사 : 2015.09.01
  • 발행 : 2015.11.01
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초록

유체이송 기술은 마이크로 유체시스템 개발에서 핵심문제로 인식되고 있다. 최근 명(2014)은 외부동력을 사용하지 않고 액적을 이동시킬 수 있는 새로운 개념을 제안하고, 초기에 반원통형 형상을 가지는 가상의 2차원 액적에 대한 수치해석을 통해 이 개념이 성립함을 보였다. 또한 명과 권(2015)은 친수성/소수성 표면위에서 초기 3차원 반구 형상의 실제 물 액적이송의 메커니즘을 시간에 따른 액적형상과 액적 내부의 운동에너지, 중력에너지, 표면자유에너지 및 압력에너지의 수치해석 결과를 통해 규명하였다. 본 연구는 새로운 개념을 확립시키기 위해 초기 구형액적에 대한 3차원 수치해석을 수행하고, 액적이송의 메커니즘을 모세관력 힘의 불균형 관점에서 액적 형상과 다양한 에너지의 수치해석 결과를 통해 규명하였다.

Fluid transport is a key issue in the development of microfluidic systems. Recently, Myong (2014) has proposed a new concept for droplet transport without external power sources, and numerically validated the results for a hypothetical 2D shape, initially having a hemicylindrical droplet shape. Myong and Kwon (2015) have also examined the transport mechanism for an actual water droplet, initially having a 3D hemispherical shape, on a horizontal hydrophilic/hydrophobic surface, based on the numerical results of the time evolution of the droplet shape, as well as the total kinetic, gravitational, pressure and surface free energies inside the droplet. In this study, a 3D numerical analysis of an initially spherical droplet is carried out to establish a new concept for droplet transport. Further, the transport mechanism of an actual water droplet is examined in detail from the viewpoint of the capillarity force imbalance through the numerical results of droplet shape and various energies inside the droplet.

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참고문헌

  1. Mettu, S. and Chaudhury, M. K., 2008 "Motion of Drops on a Surface Induced by Thermal Gradient and Vibration," Langmuir, Vol. 24, No. 19, pp. 10833-10837. https://doi.org/10.1021/la801380s
  2. Mohseni, K., Arzpeyma, A. and Dolatabadi, A., 2006, "Behaviour of a Moving Droplet under Electrowetting Actuation: Numerical Simulation," The Canadian Journal of Chemical Engineering, Vol. 84, No. 1, pp. 17-21. https://doi.org/10.1002/cjce.5450840104
  3. Banerjee, A. N., Qian, S. and Joo, S. W., 2011, "High-Speed Droplet Actuation on Single-Plate Electrode Arrays," Journal of Colloid and Interface Science, Vol. 362, No. 2, pp. 567-574. https://doi.org/10.1016/j.jcis.2011.07.014
  4. Yang, J. T., Chen, J. C., Huang, K. J. and Yeh, J. A., 2006, "Droplet Manipulation on a Hydrophobic Textured Surface with Roughened Patterns," J. Microelectromechanical Systems, Vol. 15, No. 3, pp. 697-707. https://doi.org/10.1109/JMEMS.2006.876791
  5. Chandesris, B., Soupremanien, U. and Dunoyer, N., 2013, "Uphill Motion of Droplets on Tilted and Vertical Grooved Substrates Induced by a Wettability Gradient," Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 434, pp. 126-135. https://doi.org/10.1016/j.colsurfa.2013.05.002
  6. Kooij, E. S., Jansen, H. P., Bliznyuk, O., Poelsema, B. and Zandvliet, H. J. W., 2012, "Directional Wetting on Chemically Patterned Substrates," Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 413, pp. 328-333. https://doi.org/10.1016/j.colsurfa.2011.12.075
  7. Zhu, X., Wang, H., Liao, Q., Ding, Y. D. and Gu, Y. B., 2009, "Experiments and Analysis on Self-motion Behaviors of Liquid Droplets on Gradient Surfaces," Experimental Thermal and Fluid Science, Vol. 33, No. 6, pp. 947-954. https://doi.org/10.1016/j.expthermflusci.2009.02.009
  8. Lee, J. S., Moon, J. Y. and Lee, J. S., 2014, "Study of Transporting of Droplets on Heterogeneous Surface Structure using the Lattice Boltzmann Approach," Applied Thermal Engineering , Vol. 1, No. 72, pp. 104-113.
  9. Myong, H. K., 2014, "A New Concept to Transport a Droplet on Horizontal Hydrophilic/ Hydrophobic Surfaces," Trans. Korean Soc. Mech. Eng. B, Vol. 38, No. 3, pp. 263-270. https://doi.org/10.3795/KSME-B.2014.38.3.263
  10. Myong, H. K., 2014, "Droplet Transport Mechanism on Horizontal Hydrophilic/ Hydrophobic Surfaces," Trans. Korean Soc. Mech. Eng. B, Vol. 38, No. 6, pp. 513-524. https://doi.org/10.3795/KSME-B.2014.38.6.513
  11. Myong, H. K. and Kwon, Y. H., 2014, "Numerical Analysis of the Movement of an Initially Hemispherical Droplet on Hydrophilic/ Hydrophobic Surfaces," Trans. Korean Soc. Mech. Eng. B, Vol. 39, No. 5, pp. 405-414. https://doi.org/10.3795/KSME-B.2015.39.5.405
  12. Myong, H. K. and Kwon, Y. H., 2015, "Behavior of Liquid Driven by Capillarity Force Imbalance on Horizontal Surface under Various Conditions," Trans. Korean Soc. Mech. Eng. B, Vol. 39, No. 4, pp. 359-370. https://doi.org/10.3795/KSME-B.2015.39.4.359
  13. Schiaffino, S. and Sonin, A. A., 1997, "Molten Droplet Deposition and Solidification at Low Weber Numbers," Physics of Fluids, Vol. 9, No. 11, pp. 3172-3187. https://doi.org/10.1063/1.869434
  14. Brackbill, J. U., Kothe, C. and Zamach, C., 1992, "A Continuum Method for Modeling Surface Tension," J. Comput. Phys., Vol. 100, pp. 335-354. https://doi.org/10.1016/0021-9991(92)90240-Y
  15. Myong, H. K. and Kim, J. E., 2006, "A Study on an Interface Capturing Method Applicable to Unstructured Meshes for the Analysis of Free Surface Flow," KSCFE J. of Computational Fluids Engineering, Vol. 11, No. 4, pp. 14-19.
  16. Myong, H. K., 2011, "Numerical Simulation of Surface Tension-Dominant Multiphase Flows with Volume Capturing Method and Unstructured Grid System," Trans. Korean Soc. Mech. Eng. B, Vol. 35, No. 7, pp. 723-733. https://doi.org/10.3795/KSME-B.2011.35.7.723
  17. Myong, H. K., 2012, "Numerical Study on Multiphase Flows Induced by Wall Adhesion," Trans. Korean Soc. Mech. Eng. B, Vol. 36, No. 7, pp. 721-730. https://doi.org/10.3795/KSME-B.2012.36.7.721
  18. Ubbink, O., 1997, Numerical Prediction of Two Fluid Systems with Sharp Interface, PhD Thesis, University of London.