Abstract
Liquid metal (LM) micro-droplets have been widely used in microfluidics, drug-loaded nano-system and micro-nano machine due to its excellent properties. However, there still exist difficulties in succinctly dispersing a bulk of LM into micro-droplets due to the large interfacial tension. Besides, the controllable switching between droplet dispersion and reunion is yet to be realized. Herein, a practical and efficient method for dispersing LM was proposed and the controllable switching between dispersion and reunion of LM droplets was achieved. LM micro-droplets were produced by vibrating the LM immersed in a mixture of N,N-dimethylformamide (DMF) and polyvinyl chloride (PVC). The experimental results show that the size distribution of LM micro-droplets could be tuned by controlling the vibration frequency. More intriguingly, the dispersion and reunion of LM droplets can be switched intelligently through tuning the vibration frequency and amplitude. Furthermore, optical properties of the LM micro-droplet coating were evaluated to display potential applications. A self-driven motion of PVC-coated LM could be achieved by utilizing the produced LM micro-droplets based on the Marangoni effect, which holds promising value for developing future transport tool of LM droplets. The present work suggests an entirely feasible method for dispersing and utilizing LM droplets, which is of great significance for promoting the development of LM micro-droplet science and technology.
摘要
结合了液态金属和微尺度的优点, 液态金属微液滴由于其优异的性能近年来引起了人们的高度关注, 并已被广泛应用于微流体、 载药纳米系统和微纳米机器中. 然而, 由于液态金属巨大的表面张力, 液态金属微纳米液滴的高效简易制备仍然存在困难, 特别是其分散和融合的可控且智能切换仍有待实现. 基于此, 本文提出了一种高效制备液体金属微纳米液滴的新方法, 并实现了液态金属液滴的可控分散和融合. 浸入N,N-二甲基甲酰胺(DMF)和聚氯乙烯(PVC)混合溶液中的液态金属, 通过振动可以产生微纳米级的液态金属微液滴. 实验结果表明, 控制振动的频率可以调节液态金属微液滴的尺寸分布. 更令人惊喜的是, 通过调整振动的频率和振幅, 可以实现液态金属液滴的分散和融合的智能切换, 这在可变形柔性机器等领域有着重要应用. 此外, 文章还对利用这种方法制作的液态金属微液滴涂层的光学性质进行了评估, 以证明其具有更多潜在的应用. 最后, 文章演示了利用本方法所制备的PVC包覆的液态金属微液滴可以在水面实现自驱动运动, 这对未来液态金属微液滴的运输具有重要的意义. 本文提出的这种完全可行的液态金属微液滴分散融合及其实现的方法对于液态金属微液滴科学和技术的发展具有显著的促进作用.
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This work was partially supported by the Key Project of National Natural Science Foundation of China (91748206), Dean’s Research Funding and the Frontier Project of the Chinese Academy of Sciences.
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Sen Chen received his bachelor’s degree from Huazhong University of Science and Technology in 2016. Now he is pursuing his doctor’s degree at the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences. His research interests focus on the properties and applications of room temperature liquid metals.
Lei Wang received his PhD degree from Beihang University in 2015, under the supervision of Prof. Yong-Mei Zheng. In 2017, he joined the Technical Institute of Physics and Chemistry, Chinese Academy Sciences. Now, he is an assistant researcher at the Technical Institute of Physics and Chemistry. His research interests are focused on the combination of liquid metal and bionic materials.
Jing Liu is a jointly appointed Professor of Tsinghua University (THU) and Technical Institute of Physics and Chemistry, Chinese Academy of Sciences. He received his double BSc degrees in Engineering and Physics, and PhD, all from THU and performed visiting researches at Purdue University and MIT, USA. Dr. Liu works at the interdisciplinary areas among liquid metal, biomedical engineering, and thermal science and is an author of nine popular books. His researches on liquid metal chip cooling, printed electronics, biomaterials, and soft machines initiated many game-changing technologies. Dr. Liu pioneered a group of very fundamental discoveries on liquid metals which were frequently featured over the world.
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Chen, S., Ding, Y., Zhang, Q. et al. Controllable dispersion and reunion of liquid metal droplets. Sci. China Mater. 62, 407–415 (2019). https://doi.org/10.1007/s40843-018-9325-3
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DOI: https://doi.org/10.1007/s40843-018-9325-3