Reconfigurable Active Liquid Metal Swimming Nanorobot Cluster
Robots made of liquid metal have always been an enduring sci-fi topic. Many sci-fi movies show advanced liquid metal machinery. For example, the movie "Terminator" depicts the future liquid metal robot "T-1000", which can adapt to different the function is deformed, even if it is broken into fragments, the fragments can still melt, move and reintegrate into the original shape. Liquid metal is not only active in literary and artistic creation, but also in the field of scientific research, the manufacture of liquid metal machinery has also attracted the attention of scientists. Liquid metals, especially gallium and gallium alloys, can be liquid at room temperature. They have the characteristics of fluidity, low viscosity, good biocompatibility, and high thermal conductivity. These characteristics make gallium-based liquid metals in soft materials, Intelligent robots and wearable devices have huge application prospects.
The application of liquid metal to the construction of active soft material materials and systems to obtain emergence characteristics comparable to biological systems is an important research hotspot. The biological system adapts to the surrounding environment through a dynamic and complex self-organizing structure, completes various life activities and reflects life characteristics. Individuals in the biological system can consume energy to obtain the driving force of exercise and respond to local stimuli. Inspired by the non-equilibrium dynamic self-organizing behavior of living organisms, using active swimming nanorobots to construct a reconfigurable active soft matter system with interactive and adaptive functions will provide a better understanding of the emergent self-organizing behavior of life systems. The excellent physical model also provides a new direction for the next generation of active soft material engineering.
Recently, Professor Qiang He’s research group of Harbin Institute of Technology took the ultrasonic field-activated eutectic gallium indium alloy (EGaIn) liquid metal swimming nanorobot as the building element, and proposed a reconfigurable non-equilibrium simulation of the growth process of dandelion flowers in nature Research results of liquid metal nanoclusters. The liquid metal swimming nanorobot is prepared by an ultrasound-assisted physical dispersion method, with a diameter of 200 nm and a length of 800 nm. The outer layer is a stable shell formed by GaOOH, and the inner core is unoxidized liquid metal. Under the action of the standing wave ultrasonic field, the liquid metal swimming nanorobot can perform fast and autonomous movement at a speed of up to 50 times its length per second. By adding a large number of liquid metal swimming nano-robots into the system, under the action of a standing wave ultrasonic field with a modulated frequency, the active nano-robot populations emerge and produce spontaneous gathering motion. With the adjustment of frequency, the morphology and movement behavior of aggregates gradually change, presenting a quasi-two-dimensional dynamic pattern that simulates dandelion growth, fruiting, and seed transmission with the wind. Liquid metal swimming nanorobots can be used as active assembly units to construct reconfigurable nanomachine clusters, simulate the emergent self-organizing behavior characteristics of organisms, and provide theory and technology for the next generation of liquid metal-based active soft material materials and intelligent robot manufacturing basis.