Liquid metal spring: oscillating coalescence and ejection of contacting liquid metal droplets

详细信息    查看全文

• 作者：Bin Yuan (1)
  Zhizhu He (1)
  Wenqiang Fang (1)
  Xin Bao (1)
  Jing Liu (1) (2)
  
  1. Key Laboratory of Cryogenics ; Technical Institute of Physics and Chemistry ; Chinese Academy of Sciences ; Beijing ; 100190 ; China
  2. Department of Biomedical Engineering ; School of Medicine ; Tsinghua University ; Beijing ; 100084 ; China
  
• 关键词：Liquid metal spring ; Oscillating coalescence ; Droplet ejection ; Electrical double layer ; High ; speed image experiment
• 刊名：Chinese Science Bulletin
• 出版年：2015
• 出版时间：March 2015
• 年：2015
• 卷：60
• 期：6
• 页码：648-653
• 全文大小：1,383 KB
• 参考文献：1. Liu, T, Sen, P, Kim, CJ (2012) Characterization of nontoxic liquid-metal alloy galinstan for applications in microdevices. J Microelectromech Syst 21: pp. 443-450 CrossRef
  2. Cheng, S, Wu, Z (2012) Microfluidic electronics. Lab Chip 12: pp. 2782-2791 CrossRef
  3. Ma, KQ, Liu, J (2007) Liquid metal cooling in thermal management of computer chips. Front Energy Power Eng China 1: pp. 384-402 CrossRef
  4. Li, HY, Yang, Y, Liu, J (2012) Printable tiny thermocouple by liquid metal gallium and its matching metal. Appl Phys Lett 101: pp. 073511 CrossRef
  5. Sheng, L, Zhang, J, Liu, J (2014) Diverse transformations of liquid metals between different morphologies. Adv Mater 26: pp. 6036-6042 CrossRef
  6. Warshaw, M (1967) Cloud droplet coalescence: statistical foundations and a one-dimensional sedimentation model. J Atmos Sci 24: pp. 278-286 CrossRef
  7. Jiang, YJ, Umemura, A, Law, CK (1992) An experimental investigation on the collision behaviour of hydrocarbon droplets. J Fluid Mech 234: pp. 171-190 CrossRef
  8. Orme, M (1997) Experiments on droplet collisions, bounce, coalescence and disruption. Prog Energy Combust Sci 23: pp. 65-79 CrossRef
  9. Planchette, C, Lorenceau, E, Brenn, G (2010) Liquid encapsulation by binary collisions of immiscible liquid drops. Colloid Surf A 365: pp. 89-94 CrossRef
  10. Aarts, D, Lekkerkerker, HNW (2008) Droplet coalescence: drainage, film rupture and neck growth in ultralow interfacial tension systems. J Fluid Mech 606: pp. 275-294 CrossRef
  11. Rayleigh, L, Strutt, JW (1878) On the instability of jets. Proc Lond Math Soc 10: pp. 4-13 CrossRef
  12. Morley, NB, Burris, J, Cadwallader, LC (2008) GaInSn usage in the research laboratory. Rev Sci Instrum 79: pp. 056107 CrossRef
  13. Antar, BN, Ethridge, EC, Maxwell, D (2003) Viscosity measurement using drop coalescence in microgravity. Microgravity Sci Technol 14: pp. 9-19 CrossRef
  14. Tang, SY, Khoshmanesh, K, Sivan, V (2014) Liquid metal enabled pump. Proc Natl Acad Sci USA 111: pp. 3304-3309 CrossRef
  15. Kralchevsky, PA, Denkov, ND (2001) Capillary forces and structuring in layers of colloid particles. Curr Opin Colloid Interface Sci 6: pp. 383-401 CrossRef
  16. Qian, J, Law, CK (1997) Regimes of coalescence and separation in droplet collision. J Fluid Mech 331: pp. 59-80 CrossRef
  17. Wang, FC, Yang, F, Zhao, YP (2011) Size effect on the coalescence-induced self-propelled droplet. Appl Phys Lett 98: pp. 053112 CrossRef
  18. Zhang, FH, Li, EQ, Thoroddsen, ST (2009) Satellite formation during coalescence of unequal size drops. Phys Rev Lett 102: pp. 104502 CrossRef
  19. Nikolopoulos, N, Nikas, KS, Bergeles, G (2009) A numerical investigation of central binary collision of droplets. Comput Fluids 38: pp. 1191-1202 CrossRef
  20. Stojek, Z (2002) The electrical double layer and its structure. Electroanalytical methods. Springer, Berlin
  
• 刊物主题：Science, general; Life Sciences, general; Physics, general; Chemistry/Food Science, general; Earth Sciences, general; Engineering, general;
• 出版者：Springer Berlin Heidelberg
• ISSN：1861-9541

文摘

With pretty high surface tension, the room temperature liquid metal may inherit with unexpected behaviors that conventional fluids could not own. Here, we disclosed the coalescence and ejection phenomena of liquid metal droplets via high-speed camera. It was experimentally found that, when gently contacting (rather than colliding) two metal droplets with identical size together in NaOH solution, oscillating coalescence would happen which runs just like a spring after the interface ruptures and forms capillary waves. For two metal droplets with evidently different diameters, the coalescence induces rather unusual ejection phenomena. The large droplet would swallow part of the small one and then eject another much smaller droplet. Such phenomenon provides a direct evidence for the existence of electrical double layer on metal droplets. The dynamics fluid impacting behaviors were quantified through processing images from the recorded movies, and the basic differences between the liquid metal droplets and that of water droplets were clarified. Theoretical mechanisms related to the events were preliminarily interpreted. The present finding refreshes the basic understanding of the liquid metal droplets, which also suggests potential values of applying such fundamental effects to characterize viscosity, surface tension, electrical double layer of the metal fluids and droplet formations.