In the movie Terminator 2, the T-1000 robot was made of some kind of liquid metal that could change shape among other interesting things. According to a chemical engineer at North Carolina State University, there may be something to the idea. [Michael Dickey] has been experimenting with gallium, a liquid metal, that scientists think may unlock a new generation of flexible devices.
The most common liquid metal is mercury, of course, and it has its uses. However, its toxicity has led to a reduction in its use. Gallium has low toxicity and also doesn’t easily evaporate. What can you do with it? Check out 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 readily 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] has made them. Self-healing is possible, too, since liquid metal wires would flow together — no soldering needed.
Other properties of the material make it useful for sensing deformation. For example, a mesh of liquid metal wires in a glove could help a VR system understand your hand’s gestures. One downside is that when exposed to air, the material forms a thin oxide layer. However, this also offers some advantages in fabrication that 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 boards taking advantage of liquid metal compounds that contain gallium so there is some practical application today. Combined in stretchable substrates like silicone, they can do some pretty amazing things.