posted on 2018-09-19, 00:00authored byDaolin Wang, Changyong Gao, Wei Wang, Mengmeng Sun, Bin Guo, Hui Xie, Qiang He
The
T-1000 liquid metal terminator, which can transform and self-repair,
represents a dream for decades that robots can fundamentally change
our daily life. Until now, some large-scale liquid metal machines
have been developed. However, there is no report on nanoscaled liquid
metal machines and their biomedical applications. We describe here
a shape-transformable and fusible rodlike swimming liquid metal nanomachine,
based on the biocompatible and transformable liquid metal gallium.
These nanomachines were prepared by a pressure-filter-template technology,
and the diameter and length could be controlled by adjusting the nanoporous
templates, filter time, and pressure. The as-prepared liquid gallium
nanomotors display a core–shell nanorod structure composed
of a liquid gallium core and solid gallium oxide shell. Upon exposure
to an ultrasound field, the generated acoustic radiation force in
the levitation plane can propel them to move autonomously. The liquid
metal nanomachine can actively seek cancer cells and transform from
a rod to a droplet after drilling into cells owing to the removal
of gallium oxide layers in the acidic endosomes. These transformed
nanomachines could fuse together inside cells and photothermally kill
cancer cells under illumination of near-infrared light. Such acoustically
propelled shape-transformable rodlike liquid metal nanomachines have
great potential for biomedical applications.