  The room temperature liquid metal is quickly emerging as an important
functional material in a variety of areas like chip cooling, 3D printing or
printed electronics etc. With diverse capabilities in electrical, thermal and
flowing behaviors, such fluid owns many intriguing properties that had never
been anticipated before. Here, we show a group of unconventional phenomena
occurring on the liquid metal objects. Through applying electrical field on the
liquid metals immersed in water, a series of complex transformation behaviors
such as self-assembling of a sheet of liquid metal film into a single sphere,
quick mergences of separate metal droplets, controlled self-rotation and planar
locomotion of liquid metal objects can be realized. Meanwhile, it was also
found that two accompanying water vortexes were induced and reliably swirled
near the rotating liquid metal sphere. Further, effects of the shape, size,
voltage, orientation and geometries of the electrodes to control the liquid
metal transformers were clarified. Such events are hard to achieve otherwise on
rigid metal or conventional liquid spheres. This finding has both fundamental
and practical significances which suggest a generalized way of making smart
soft machine, collecting discrete metal fluids, as well as flexibly
manipulating liquid metal objects including accompanying devices.
