In the movie Terminator 2, the T-1000 robot was made of a kind of liquid metal that, among other things, could change shape. According to a chemical engineer at North Carolina State University, there may be something about the idea. [Michael Dickey] has experimented with gallium, a liquid metal that scientists believe could unlock a new generation of flexible devices.
The most common liquid metal is, of course, mercury, and it has its uses. However, its toxicity has led to a reduction in use. Gallium has low toxicity and does not evaporate easily either. What can you do about it? Watch the video below to see a very simple demonstration of the liquid metal lifting a small – very small – weight with an electrical impulse.
Like most metals, gallium transfers heat and electricity easily, but can change shape without the fatigue associated with normal metals. Imagine, for example, headphones that have liquid metal wires that can stretch without breaking. [Dickey] have made them. Self-healing is also possible as liquid metal wires would flow together – no soldering required.
Other properties of the material make it useful for detecting deformation. For example, a net of liquid metal wires in a glove can help a VR system to understand the movements of your hand. A disadvantage is that when exposed to air, the material forms a thin oxide layer. However, this also provides some benefits in manufacturing, which they mention in the post.
Of course, this is far from practical today, but it might just be a technology to watch. We have seen a few flexible sheets utilize liquid metal compounds that contain gallium, so there is some practical use today. Combined in stretchy pads like silicone, they can do some pretty amazing things.