RESEARCH

Biofluiddynamics    Drops    Bubbles    Soft Matter    Nanofabrication   




Drops

Liquid slug manipulation in microscales

We study the propulsion and control of liquid menisci confined within micro/nanochannels using thermocapillarity, capillary burst valves and electrowetting.


Related publications
1. H.-Y. Kim, ¡°On thermocapillary propulsion of microliquid slug,¡± Nanoscale and Microscale Thermophysical Engineering 11, 351-362 (2007)
2. H. Cho, H.-Y. Kim, J. Y. Kang, and T. S. Kim, ¡°How the capillary burst microvalve works,¡± Journal of Colloid and Interface Science 306, 379-385 (2007)
3. D.-G. Lee, J. Park, J. Bae, and H.-Y. Kim, ¡°Dynamics of a microliquid prism actuated by electrowetting,¡± Lab on a Chip 13, 274-279 (2013)
4. A. Lee, and H.-Y. Kim, ¡°Does liquid slippage within a rough channel always increase the flow rate?,¡± Physics of Fluids 26, 07002 (2014)
5. M. Kang, W. Park, S. Na, S. Paik, H. Lee, J. Park, H.-Y. Kim, and N. L. Jeon, ¡°Capillarity guided patterning of microliquids,¡± Small 11, 2789-2797 (2015)
6. J. Ha, J. Park, Y. Kim, B. Shin, J. Bae and H.-Y. Kim, ¡°Interfacial waves generated by electrowetting-driven contact line motion," Physics of Fluids 28, 102102 (2016)
7. Y. Lee, J. W. Choi, J. Yu, D. Park, J. Ha, K. Son, S. Lee, M. Chung, H.-Y. Kim, and N. L. Jeon, ¡°Microfluidics within a well: an injection-molded plastic array 3D culture platform," Lab on a Chip 18, 2433-2440 (2018)
8. D. Park, J. Lee, Y. Lee, K. Son, J. W. Choi, W. J. Jeang, H. Choi, Y. Hwang, H.-Y. Kim, and N. L. Jeon, ¡°Aspiration-mediated hydrogel micropatterning using rail-based open microfluidic devices for high-throughput 3D cell culture," Scientific Reports 11, 19986 (2021)
9. J. Kim, Y. Jung, and H.-Y. Kim, ¡°Evaporative capillary rise," Physical Review Fluids 7, L032001 (2022)



Drop impact behavior

Drop impact is a fascinating phenomenon showing the beauty of interfacial flows, which emerges in diverse natural and industrial situations. We perform fundamental research associated with drop impact onto solid surface, such as the origin of splashing and physical mechanism of recoiling.


Related publications
1. H.-Y. Kim, Z. C. Feng, and J.-H. Chun, ¡°Instability of a liquid jet emerging from a droplet upon collision with a solid surface,¡± Physics of Fluids 12, 531-541 (2000)
2. H.-Y. Kim and J.-H. Chun, ¡°The recoiling of liquid droplets upon collision with solid surfaces,¡± Physics of Fluids 13, 643-659 (2001)
3. Y.-S. Yang, H.-Y. Kim, and J.-H. Chun, ¡°Spreading and solidification of a molten microdrop in the solder jet bumping process,¡± IEEE Transactions on Components and Packaging Technologies 26, 215-221 (2003)
4. H.-Y. Kim, S.-Y. Park, and K. Min, ¡°Imaging the high-speed impact of microdrop on solid surface,¡± Review of Scientific Instruments 74, 4930-4937 (2003)
5. H.-Y. Kim, T. Karahalios, T. Qiu, and J.-H. Chun, ¡°Microsensor for impact of molten metal microdrops,¡± Sensors and Actuators A: Physical 116, 417-423 (2004)
6. H. J. Lee and H.-Y. Kim, ¡°Control of drop rebound with solid target motion,¡± Physics of Fluids 16, 3715-3719 (2004)
7. M. Lee, Y. S. Chang, and H.-Y. Kim, ¡°Drop impact on microwetting patterned surfaces,¡± Physics of Fluids 22, 072101 (2010)
8. S. Kim, M.-W. Moon, and H.-Y. Kim, ¡°Drop impact on super-wettability-contrast annular patterns,¡± Journal of Fluid Mechanics 703, 328-342 (2013)
9. H. Kim, J. Lee, T.-H. Kim, and H.-Y. Kim, ¡°Spontaneous Marangoni mixing of miscible liquids at a liquid-liquid-air contact line,¡± Langmuir 31, 8726-8731 (2015)
10. J. H. Lee, S. Kim, J. Kim, H. Kim, and H.-Y. Kim, ¡°From an elongated cavity to funnel by the impact of a drop train,¡± Journal of Fluid Mechanics 921, A8 (2021)


Cover of the July issue of Physics of Fluids (2010): Ref. 7



Drops, rivulets, and films on solid surfaces

Related publications
1. H.-Y. Kim, H. J. Lee, and B. H. Kang, “Sliding of liquid drops down an inclined solid surface,” Journal of Colloid and Interface Science 247, 72-380 (2002)
2. H.-Y. Kim, J.-H. Kim, and B. H. Kang, “Meandering instability of a rivulet,” Journal of Fluid Mechanics 493, 245-256 (2004)
3. H.-Y. Kim, “Drop fall-off from the vibrating ceiling,” Physics of Fluids 16, 474-477 (2004)
4. J. H. Moon, B. H. Kang, and H.-Y. Kim, “The lowest oscillation mode of a pendant drop,” Physics of Fluids 18, 021702 (2006)
5. S. J. Kim, M.-W. Moon, K.-R. Lee, D.-Y. Lee, Y. S. Chang, and H.-Y. Kim, “Liquid spreading on superhydrophilic micropillar arrays,” Journal of Fluid Mechanics 680, 477-487 (2011)
6. J. Kim, M.-W. Moon, K.-R. Lee, L. Mahadevan, and H.-Y. Kim, “Hydrodynamics of writing with ink,” Physical Review Letters 107, 264501 (2011)
7. A. Lee, M.-W. Moon, H. Lim, W.-D. Kim, and H.-Y. Kim, “Water harvest via dewing,” Langmuir 28, 10183-10191 (2012)
8. J. Park, J. Park, H. Lim, and H.-Y. Kim, “Shape of a large drop on a rough hydrophobic surface,” Physics of Fluids 25, 022102 (2013)
9. S. J. Kim, J. Kim, M.-W. Moon, K.-R. Lee, and H.-Y. Kim, “Experimental study of drop spreading on textured superhydrophilic surfaces,” Physics of Fluids 25, 092110 (2013)
10. B. Shin, M.-W. Moon, and H.-Y. Kim, “Rings, igloos and pebbles of salt formed by drying saline drops,” Langmuir 30, 12837−12842 (2014)
11. S. J. Kim, J. W. Choi, M.-W. Moon, K.-R. Lee, Y. S. Chang, D.-Y. Lee, and H.-Y. Kim, “Wicking and flooding of liquids on vertical porous sheets,” Physics of Fluids 27, 032105 (2015)
12. D. H. Kim, M. C. Jung, S.-H. Cho, S. H. Kim, H.-Y. Kim, H. J. Lee, K. H. Oh, and M.-W. Moon, “UV-responsive nano-sponge for oil absorption and desorption,” Scientific Reports 5, 12908 (2015)
13. J. Kim, M.-W. Moon, and H.-Y. Kim, “Dynamics of hemiwicking,” Journal of Fluid Mechanics 800, 57-71 (2016)
14. J. Kim, J. Ha, and H.-Y. Kim, “Capillary rise of non-aqueous liquids in cellulose sponges,” Journal of Fluid Mechanics 818, R2 (2017)
15. S. Kim, J. Kim, and H.-Y. Kim, “Dewetting of liquid film via vapour-mediated Marangoni effect,” Journal of Fluid Mechanics 872, 100-114 (2019)
16. S. Kim, J. Kim, and H.-Y. Kim, “Formation, growth, and saturation of dry holes in thick liquid films under vapor-mediated Marangoni effect,” Physics of Fluids 31, 112105 (2019)
17. C. Yun, J. W. Choi, H. Kim, D. Kim, and H.-Y. Kim, “Sliding on ice: Real contact area, melted film thickness, and friction force,” International Journal of Heat and Mass Transfer 160, 120166 (2020)
18. C. J. Park, J. Ha, J. H. Lee, and H.-Y. Kim, “Coalescence of oil drops and films on micropillared substrates enabled by enhanced water drainage through pillar gaps,” Soft Matter 17, 5888-5896 (2021)
19. S. Kim, M.-Y. Moon, and H.-Y. Kim, “Liquid spreading along nanostructured superhydrophilic lanes,” Physical Review Fluids 6, 034002 (2021)
20. J. H. Lee, B. Jung, G.-S. Park, and H.-Y. Kim, “Condensation and wicking of water on solid nanopatterns,” Physical Review Fluids 7, 024202 (2022)


Cover of Journal of Fluid Mechanics volume 872 (2019): Ref. 15