期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2022
卷号:119
期号:6
DOI:10.1073/pnas.2117535119
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Significance
Streams of fluids, particulates, and other flowing media are difficult to control after they have left a nozzle. Here, we present the noncontact manipulation of a free-flowing stream of liquid metal. Such streams form by electrochemically lowering the interfacial tension. The electrochemical reactions make the streams into soft current–carrying conductors presenting minimal resistance to manipulation via the Lorentz force in the magnetic field. Meanwhile, the movement of the stream induces a secondary force arising from Lenz’s law that causes the manipulated streams to levitate in unique shapes. This work, which exploits these forces in a visually stunning manner, enables shaping of fluids in a noncontact manner.
This paper reports the noncontact manipulation of free-falling cylindrical streams of liquid metals into unique shapes, such as levitated loops and squares. Such cylindrical streams form in aqueous media by electrochemically lowering the interfacial tension. The electrochemical reactions require an electrical current that flows through the streams, making them susceptible to the Lorentz force. Consequently, varying the position and shape of a magnetic field relative to the stream controls these forces. Moreover, the movement of the metal stream relative to the magnetic field induces significant forces arising from Lenz’s law that cause the manipulated streams to levitate in unique shapes. The ability to control streams of liquid metals in a noncontact manner will enable strategies for shaping electronically conductive fluids for advanced manufacturing and dynamic electronic structures.
关键词:enliquid metal wirenoncontact manipulationlevitated patternselectromagnetism