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Autonomous convergence and divergence of the self-powered soft liquid metal vehicles

自驱动柔性液态金属车辆之间的自主融合与分离

Abstract

Conventional rigid machines, even biological systems in nature, generally do not own the capabilities like autonomous convergence or divergence. Here, such extraordinary behavior was demonstrated for the first time with the liquid metal vehicle. This synthetic soft machine fueled with an aluminum flake could initiate its autonomous locomotion in an open-top circular channel containing NaOH solution, like a running vehicle. If cutting a large machine into several smaller separately running vehicles, each of them still resumes its traveling state along the original track and chases each other. If the volumes of such dispersive vehicles were close to each other and they were all squeezed in the channel, the vehicles would move synchronously with oscillation. Otherwise, such self-motion would become desynchronized with interval between the inequable vehicles decreased gradually. If their volumes were significantly different, and the smaller vehicles were not squeezed in the channel, the faster vehicle would overtake the slower ones, until they finally coalesced seamlessly. The assembled vehicle could deform itself along with change of its velocity. This finding may shed light on future researches on smart material, fluid mechanics and soft matter to self-fueled machine and biomimics. It would also offer opportunities for constructing self-reconfigurable soft robots.

摘要

传统由刚性材料制成的机器,甚至是自然界中的生物体,一般均不具备自动融合或分离运动的能力。本文首次证实了由液态金属制成的车辆机器的此种非凡表现。这一合成的柔性机器通过一小块铝片提供燃料,以驱动机器在内含NaOH溶液的环形无盖槽道中如同不断前进的车辆一样自主运动。如果将大的机器分割成几个小的独立运行车辆,则每个小车辆均可沿原来轨道保持运动状态并相互追逐。如果分离的多个车辆的体积相差不大且在槽道中都处于被挤压状态时,则车辆会以同步振荡方式协同前进。否则,这种自主运动就不再同步,且彼此间距离会逐渐缩小。若各自的体积相差较大,且较小车辆在槽道中并未受到挤压,那么行驶快的车辆有可能追上行驶较慢者,从而发生相互碰撞而实现完全无缝的融合。合并后自组装成的车辆会随着速度的变化而发生变形。这一发现有望对未来涉及从智能材料、流体力学、软物质到自驱动机器乃至仿生学研究起到一定启示作用,同时也会为今后构建可自行重构的柔性机器人提供契机。

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Acknowledgments

This work was partially supported by the National Natural Science Foundation of China (51376102).

Conflict of interest

The authors declare that they have no conflict of interest.

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Corresponding author

Correspondence to Jing Liu.

Additional information

Jie Zhang and Youyou Yao contributed equally to this work.

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Zhang, J., Yao, Y. & Liu, J. Autonomous convergence and divergence of the self-powered soft liquid metal vehicles. Sci. Bull. 60, 943–951 (2015). https://doi.org/10.1007/s11434-015-0786-z

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Keywords

  • Liquid metal
  • Self-fueled machine
  • Soft robot
  • Autonomous convergence and divergence
  • Soft matter

关键词

  • 液态金属
  • 自驱动机器
  • 柔性机器人
  • 自主合并及分离
  • 软物质