Translated by: Wang Min
The world’s first shape-transformable and fusible swimming liquid metal nanomachine is developed by Guo Bin and He Qiang, professors from State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology (HIT) . The research was published in ACS Nano (IF: 13.7), an internationally renowned journal, titled “Shape-Transformable, Fusible Rodlike Swimming Liquid Metal Nanomachine”.
Alloyed gallium with a temperature melting point of 29.8℃ stays in a liquid state at room temperature. In effect, the liquid gallium and its alloy are characterized with various excellent properties such as high boiling point, low viscosity, good thermal conductivity, electrical conductivity, liquidity and biocompatibility. The research in applying liquid gallium and its alloy to robotics, biomedicine and wearable devices is on the rise, especially after the liquid metal robot “T-1000” in the film Terminator shows its potential to freely transform, self-repair and imitate any object which is of similar size. However, there is no report on nanoscaled liquid metal machines.
Fortunately, taking liquid gallium as raw material, the research team of HIT has for the first time developed the rodlike liquid gallium nanomachine with asymmetric structure by nanoporous template plastic forming technique. This nanomachine is controllable in length and diameter, with a minimum diameter of 200 nanometers. According to the research, the rodlike liquid metal nanomachine displays a core-shell structure composed of a gallium core and a gallium oxide shell. Due to the pre-melting effect of the nanoscaled gallium, the core is able to remain in a liquid state even at room temperature, whereas the outer gallium oxide shell can maintain a rod-like structure. Meanwhile, it is also found that the liquid metal nanomachine with stable full-wavelength fluorescence can be used as a fluorescent probe for precise diagnosis and treatment of diseases. Moreover, under the action of external ultrasonic field, the liquid metal nanomachine like swimming bacteria is able to perform self-propelled motion in the fluid at a speed of 23 microns per second. The nanomachine can also target cancer cells actively. Then after it enters the cancer cell, its shell tends to be dissolved while its core tends to be deformed, fused and completely degraded under acidic conditions. Similar as T-1000 with the ability of transformation and fusion, the liquid metal nanomachine will provide new insights into the design, manufacture and biomedical applications of next-generation micro-nano machines.
Links to the source article:https://pubs.acs.org/doi/10.1021/acsnano.8b05203