Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, School of Medicine, Shenzhen University, Shenzhen 518000, China;
Department of Mechanical Engineering, University of Hong Kong, Hong Kong 999077.
Proc Natl Acad Sci U S A. 2018 Jun 12;115(24):6159-6164. doi: 10.1073/pnas.1801053115. Epub 2018 May 25.
We investigate the dynamics of an electrified liquid filament in a nozzle-to-substrate configuration with a close separation. The interplay between compressive viscous and electrostatic stresses dictates previously undocumented transitions between dynamic regimes of "jetting," "coiling," and "whipping." In particular, the onsets of both coiling and whipping instabilities are significantly influenced by the minimum radius along the liquid filament. Using a low-interfacial-tension system, we unravel the physics behind the transitions between jetting, coiling, and whipping of an electrified filament for a range of liquid properties and geometric parameters. Our results enrich the overall physical picture of the electrically forced jets, and provide insights for the emerging high-resolution instability-assisted printing of materials such as folded assemblies and scaffolds.
我们研究了在具有紧密分离的喷嘴到基底配置中，带电液体细丝的动力学。压缩粘性和静电应力的相互作用决定了之前未记录的“喷射”、“缠绕”和“鞭笞”动态状态之间的转变。特别是，缠绕和鞭笞不稳定性的开始都受到液体细丝沿最小半径的显著影响。使用低界面张力系统，我们揭示了一系列液体性质和几何参数下，带电细丝从喷射、缠绕到鞭笞转变的物理原理。我们的结果丰富了电驱动射流的整体物理图景，并为新兴的高分辨率不稳定性辅助打印材料（如折叠组件和支架）提供了见解。
