I hate to break it to you, but that fancy 3D printer you just plopped down a lot of money for is already extinct. That's because researchers at North Carolina State University have come up with a 3D-printing method using liquid metal at room temperature. It's something they have been working on for years as trying to build a structure using liquid metal at room temperature without having it turn into a puddle proved difficult.
The process uses a tiny syringe to apply small drops of liquid metal composed of gallium and indium together. It's a thin oxide skin that is able to hold it all together and overcome the effects of gravity and the large surface tension of the liquid.
Using this method, they are able to build all sorts of things but perhaps most interesting of them all is creating wire. Applying a pressurized air pulse through the syringe makes an instant wire. Conversely, applying vacuum detaches the wire.
In a discussion of the project on Reddit, one of the researchers noted that the cool thing about it (from a scientific standpoint) is that liquids don't behave this way normally. The wires created using the process should simply break up into a rain of droplets while the structures should just melt into a puddle.
The technology could lead to some interesting uses in the electronics field. For example, 3D-printed wire could be used as headphone wires where attributes like flexibility and the ability to self-heal could be paramount.