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The lotus effect refers to self-cleaning properties that are a result of ultrahydrophobicity as exhibited by the leaves of Nelumbo,the lotus flower. Dirt particles are picked up by water droplets due to the micro- and nanoscopic architecture on the surface,which minimizes the droplet's adhesion to that surface. Ultrahydrophobicity and self-cleaning properties are also found in other plants,such as Tropaeolum (nasturtium),Opuntia,Alchemilla,cane,and also on the wings of certain insects.
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References
- ↑ "APS Fellow Archive". www.aps.org.
- ↑ "Droplet".
- ↑ "Ho-Young Kim".
- ↑ "Ho-Young Kim – Mahadevan Natural Philosophy".
- ↑ "HOME/PEOPLE". fluids.snu.ac.kr.
- ↑ "IUTAM Symposium on Capillarity and Elastocapillarity in Biology".
- ↑ Lee, Duck-Gyu; Kim, Ho-Young (January 1, 2008). "Impact of a Superhydrophobic Sphere onto Water". Langmuir. 24 (1): 142–145. doi:10.1021/la702437c. PMID 17999546 – via CrossRef.
- ↑ Lee, Duck-Gyu; Kim, Ho-Young (April 5, 2009). "The role of superhydrophobicity in the adhesion of a floating cylinder". Journal of Fluid Mechanics. 624: 23–32. doi:10.1017/S002211200900593X. S2CID 36329301 – via Cambridge University Press.
- ↑ Vella, Dominic; Lee, Duck-Gyu; Kim, Ho-Young (July 1, 2006). "The Load Supported by Small Floating Objects". Langmuir. 22 (14): 5979–5981. doi:10.1021/la060606m. PMID 16800646 – via CrossRef.
- ↑ Vella, Dominic; Lee, Duck-Gyu; Kim, Ho-Young (March 1, 2006). "Sinking of a Horizontal Cylinder". Langmuir. 22 (7): 2972–2974. doi:10.1021/la0533260. PMID 16548544 – via CrossRef.
- ↑ "Sinking of small sphere at low Reynolds number through interface".
- ↑ Yang, Eunjin; Son, Jae Hak; Lee, Sang-im; Jablonski, Piotr G.; Kim, Ho-Young (December 7, 2016). "Water striders adjust leg movement speed to optimize takeoff velocity for their morphology". Nature Communications. 7 (1): 13698. doi: 10.1038/ncomms13698 . PMC 5150985 . PMID 27924805.
- ↑ Koh, Je-Sung; Yang, Eunjin; Jung, Gwang-Pil; Jung, Sun-Pill; Son, Jae Hak; Lee, Sang-Im; Jablonski, Piotr G.; Wood, Robert J.; Kim, Ho-Young; Cho, Kyu-Jin (July 31, 2015). "Jumping on water: Surface tension–dominated jumping of water striders and robotic insects". Science. 349 (6247): 517–521. doi:10.1126/science.aab1637. PMID 26228144. S2CID 21807520 – via CrossRef.
- ↑ "Jumping hoops".
- ↑ Park, Yong-Jai; Jeong, Useok; Lee, Jeongsu; Kwon, Seok-Ryung; Kim, Ho-Young; Cho, Kyu-Jin (2012). "Kinematic Condition for Maximizing the Thrust of a Robotic Fish Using a Compliant Caudal Fin". IEEE Transactions on Robotics. 28 (6): 1216–1227. doi:10.1109/TRO.2012.2205490. S2CID 16277044.
- ↑ Lee, Jeongsu; Park, Yong-Jai; Jeong, Useok; Cho, Kyu-Jin; Kim, Ho-Young (April 5, 2013). "Wake and thrust of an angularly reciprocating plate". Journal of Fluid Mechanics. 720: 545–557. doi:10.1017/jfm.2013.50. S2CID 43976184 – via Cambridge University Press.
- ↑ "A scaling law for the lift of hovering insects".
- ↑ Bae, Jihyun; Lee, Jeongsu; Kim, SeongMin; Ha, Jaewook; Lee, Byoung-Sun; Park, YoungJun; Choong, Chweelin; Kim, Jin-Baek; Wang, Zhong Lin; Kim, Ho-Young; Park, Jong-Jin; Chung, U.-In (September 23, 2014). "Flutter-driven triboelectrification for harvesting wind energy". Nature Communications. 5 (1): 4929. doi: 10.1038/ncomms5929 . PMID 25247474.
- ↑ Kim, Ho-Young; Mahadevan, L. (February 5, 2006). "Capillary rise between elastic sheets". Journal of Fluid Mechanics. 548: 141–150. doi:10.1017/S0022112005007718. S2CID 17379192 – via Cambridge University Press.
- ↑ "Equilibrium of an elastically confined liquid drop".
- 1 2 Lee, Heon Ju; Chang, Young Soo; Lee, Yoon Pyo; Jeong, Kwang-Hun; Kim, Ho-Young (May 16, 2007). "Deflection of microcantilever by growing vapor bubble". Sensors and Actuators A: Physical. 136 (2): 717–722. doi:10.1016/j.sna.2007.01.004 – via ScienceDirect.
- ↑ Park, Kun Joong; Kim, Ho-Young (September 5, 2008). "Bending of floating flexible legs". Journal of Fluid Mechanics. 610: 381–390. doi:10.1017/S0022112008002784. S2CID 43925050 – via Cambridge University Press.
- ↑ "Evaporation-driven clustering of microscale pillars and lamellae".
- ↑ "Wicking and flooding of liquids on vertical porous sheets".
- ↑ "Bending and buckling of wet paper".
- ↑ Kim, Seong Jin; Moon, Myoung-Woon; Lee, Kwang-Ryeol; Lee, Dae-Young; Chang, Young Soo; Kim, Ho-Young (August 5, 2011). "Liquid spreading on superhydrophilic micropillar arrays". Journal of Fluid Mechanics. 680: 477–487. doi:10.1017/jfm.2011.210. S2CID 43975669 – via Cambridge University Press.
- ↑ "Experimental study of drop spreading on textured superhydrophilic surfaces".
- ↑ Kim, Jungchul; Moon, Myoung-Woon; Kim, Ho-Young (August 5, 2016). "Dynamics of hemiwicking". Journal of Fluid Mechanics. 800: 57–71. doi:10.1017/jfm.2016.386. S2CID 43936306 – via Cambridge University Press.
- ↑ Kim, Jungchul; Moon, Myoung-Woon; Lee, Kwang-Ryeol; Mahadevan, L.; Kim, Ho-Young (December 20, 2011). "Hydrodynamics of Writing with Ink". Physical Review Letters. 107 (26): 264501. doi:10.1103/PhysRevLett.107.264501. PMID 22243158. S2CID 11532376 – via APS.
- ↑ Lee, Anna; Moon, Myoung-Woon; Lim, Hyuneui; Kim, Wan-Doo; Kim, Ho-Young (July 10, 2012). "Water harvest via dewing". Langmuir. 28 (27): 10183–10191. doi:10.1021/la3013987. PMID 22731870 – via CrossRef.
- ↑ "Shape of a large drop on a rough hydrophobic surface".
- ↑ "Drop impact on microwetting patterned surfaces | Physics of Fluids | AIP Publishing".
- ↑ Kim, Seungho; Moon, Myoung-Woon; Kim, Ho-Young (September 5, 2013). "Drop impact on super-wettability-contrast annular patterns". Journal of Fluid Mechanics. 730: 328–342. doi:10.1017/jfm.2013.358. S2CID 43951043 – via Cambridge University Press.
- ↑ "Mechanism of particle removal by megasonic waves | Applied Physics Letters | AIP Publishing".
- ↑ Kim, Wonjung; Park, Keunhwan; Oh, Jongkeun; Choi, Jaehyuck; Kim, Ho-Young (August 1, 2010). "Visualization and minimization of disruptive bubble behavior in ultrasonic field". Ultrasonics. 50 (8): 798–802. doi:10.1016/j.ultras.2010.04.002. PMID 20462624 – via ScienceDirect.
- ↑ Kim, Tae-Hong; Kim, Ho-Young (July 5, 2014). "Disruptive bubble behaviour leading to microstructure damage in an ultrasonic field". Journal of Fluid Mechanics. 750: 355–371. doi:10.1017/jfm.2014.267. S2CID 43938609 – via Cambridge University Press.
- ↑ "Life of thermal bubble on platinum microheater".
- ↑ Chang, Young Soo; Jeong, Kwang-Hun; Lee, Heon Ju; Lee, Yoon Pyo; Kim, Ho-Young (January 1, 2010). "Behavior of thermal bubbles formed from a single nucleation site". Journal of Mechanical Science and Technology. 24 (1): 415–420. doi:10.1007/s12206-009-1112-y. S2CID 55871855 – via Springer Link.
- ↑ Cha, Tae-Gon; Yi, Jin Woo; Moon, Myoung-Woon; Lee, Kwang-Ryeol; Kim, Ho-Young (June 1, 2010). "Nanoscale Patterning of Microtextured Surfaces to Control Superhydrophobic Robustness". Langmuir. 26 (11): 8319–8326. doi:10.1021/la9047402. PMID 20151676 – via CrossRef.
- ↑ Ahmed, Sk. Faruque; Rho, Geon-Ho; Lee, Ji Yeong; Kim, Seong Jin; Kim, Ho-Young; Jang, Yong-Jun; Moon, Myoung-Woon; Lee, Kwang-Ryeol (December 25, 2010). "Nano-embossed structure on polypropylene induced by low energy Ar ion beam irradiation". Surface and Coatings Technology. 205: S104–S108. doi:10.1016/j.surfcoat.2010.06.005 – via ScienceDirect.
- ↑ Shin, Bongsu; Lee, Kwang-Ryeol; Moon, Myoung-Woon; Kim, Ho-Young (January 18, 2012). "Extreme water repellency of nanostructured low-surface-energy non-woven fabrics". Soft Matter. 8 (6): 1817–1823. doi:10.1039/C1SM06867A – via pubs.rsc.org.
- ↑ Yi, Jin Woo; Moon, Myoung-Woon; Ahmed, Sk. Faruque; Kim, Haeri; Cha, Tae-Gon; Kim, Ho-Young; Kim, Seock-Sam; Lee, Kwang-Ryeol (November 16, 2010). "Long-Lasting Hydrophilicity on Nanostructured Si-Incorporated Diamond-Like Carbon Films". Langmuir. 26 (22): 17203–17209. doi:10.1021/la103221m. PMID 20923155 – via CrossRef.
- ↑ Dai, Wei; Kim, Seong Jin; Seong, Won-Kyung; Kim, Sang Hoon; Lee, Kwang-Ryeol; Kim, Ho-Young; Moon, Myoung-Woon (August 28, 2013). "Porous Carbon Nanoparticle Networks with Tunable Absorbability". Scientific Reports. 3 (1): 2524. doi: 10.1038/srep02524 . PMC 3755281 . PMID 23982181.
- ↑ Moon, Myoung-Woon; Cha, Tae-Gon; Lee, Kwang-Ryeol; Vaziri, Ashkan; Kim, Ho-Young (August 3, 2010). "Tilted Janus polymer pillars". Soft Matter. 6 (16): 3924–3929. doi:10.1039/C0SM00126K – via pubs.rsc.org.
- ↑ Jeong, Seongpil; Shin, Bongsu; Jo, Wonjin; Kim, Ho-Young; Moon, Myoung-Woon; Lee, Seockheon (December 1, 2016). "Nanostructured PVDF membrane for MD application by an O2 and CF4 plasma treatment". Desalination. 399: 178–184. doi:10.1016/j.desal.2016.09.001 – via ScienceDirect.
- ↑ Kim, Ho-Young; Lee, Minhee; Park, Kun Joong; Kim, Sungho; Mahadevan, L. (June 9, 2010). "Nanopottery: Coiling of Electrospun Polymer Nanofibers". Nano Letters. 10 (6): 2138–2140. doi:10.1021/nl100824d. PMID 20486713 – via CrossRef.
- ↑ Lee, Minhee; Kim, Ho-Young (February 11, 2014). "Toward Nanoscale Three-Dimensional Printing: Nanowalls Built of Electrospun Nanofibers". Langmuir. 30 (5): 1210–1214. doi:10.1021/la404704z. PMID 24471865 – via CrossRef.
- ↑ Shin, Beomjune; Ha, Jonghyun; Lee, Minhee; Park, Keunhwan; Park, Gee Ho; Choi, Tae Hyun; Cho, Kyu-Jin; Kim, Ho-Young (January 31, 2018). "Hygrobot: A self-locomotive ratcheted actuator powered by environmental humidity". Science Robotics. 3 (14). doi: 10.1126/scirobotics.aar2629 . PMID 33141700.
- ↑ Shin, Beomjune; Jung, Yeonsu; Choi, Munkyeong; Kim, Ho-Young (October 26, 2022). "Thermodynamics of Hygroresponsive Soft Engines: Cycle Analysis and Work Ratio". Physical Review Applied. 18 (4): 044061. doi:10.1103/PhysRevApplied.18.044061. S2CID 253170334 – via APS.
- ↑ Ha, Jonghyun; Kim, Ho-Young (January 5, 2020). "Capillarity in Soft Porous Solids". Annual Review of Fluid Mechanics. 52 (1): 263–284. doi:10.1146/annurev-fluid-010518-040419. S2CID 202129694 – via CrossRef.
- ↑ Son, Kyungmin; Sun, Jeong-Yun; Kim, Ho-Young (August 18, 2021). "Agile reversible shape-morphing of particle rafts". Soft Matter. 17 (32): 7554–7564. doi: 10.1039/D1SM00564B . PMID 34337636.
- ↑ Park, Chan Jin; Ha, Jonghyun; Lee, Hae-Ryung; Park, Keunhwan; Sun, Jeong-Yun; Kim, Ho-Young (January 10, 2023). "Plant cell-like tip-growing polymer precipitate with structurally embedded multistimuli sensing ability". Proceedings of the National Academy of Sciences. 120 (2): e2211416120. doi:10.1073/pnas.2211416120. PMC 9926264 . PMID 36595665.