3-D Structures Built Out of Liquid Metal At Room Temperature 72
ph4cr writes with news that a few researchers have discovered an alloy that allows them to print 3D structures from liquid metal at room temperature. From the article: "'It's difficult to create structures out of liquids, because liquids want to bead up. But we’ve found that a liquid metal alloy of gallium and indium reacts to the oxygen in the air at room temperature to form a "skin" that allows the liquid metal structures to retain their shapes,' says Dr. Michael Dickey, an assistant professor of chemical and biomolecular engineering at NC State and co-author of a paper describing the work. ... One technique involves stacking droplets of liquid metal on top of each other, much like a stack of oranges at the supermarket. The droplets adhere to one another, but retain their shape – they do not merge into a single, larger droplet. ... Another technique injects liquid metal into a polymer template, so that the metal takes on a specific shape. The template is then dissolved, leaving the bare, liquid metal in the desired shape. The researchers also developed techniques for creating liquid metal wires, which retain their shape even when held perpendicular to the substrate."
The paper is available online. There's also a video of the process in action, below the fold.
Okay (Score:5, Interesting)
That's quite impressive. The obvious "next step" in 3D printing, but how realistic is it to a home user? We already have myriad ways to lay circuits etc. out, and the point of 3D printing is not that we could never make little plastic shapes before, but that it's something I can do as much as I like if I buy a 3D printer, raw materials and some model plans, without requiring specialist knowledge or handling.
Does this let me add metals into my 3d plans? Does this allow me to print circuit boards (hmmm... sounds familiar....)? Or is it just an impractical way of doing the same things with a single alloy that we can do any number of other ways.
What's the killer application here? Could I 3D print a working set of Christmas lights without having to worry about bulbs, cables, wires, circuits boards, etc? Just have a device with two nozzles that does all the hard work and just churns out the completed product from a plan? I'm guessing not, or at least not before something else will come along and make that possible.
But, still, it's very nice to watch and dream.
Uses in self healing wires (Score:2, Interesting)
I think the better use for the material is in self healing wires. Stretchable, bendable, maybe even cutable.. then the liquid can re attack to itself.
gallium is expensive (Score:5, Interesting)
I'm paying $25 for a kilogram of 3D-printable ABS filament. A kilogram of gallium is probably close to $1000, based on prices I've seen on ebay.
Re:Okay (Score:4, Interesting)
The 'next step' is probably not printing with eutectic InGal alloys, but with other metals that exhibit the same properties but at higher melting points. One of the paper authors casually mentioned on Reddit that Aluminium happens to have the right properties.
If you're willing to accept long print times, melting microlitre/picolitre quantities of Aluminium with an induction heating nozzle seems entirely possible to do at home.
Re:Okay (Score:5, Interesting)
Why not use existing Tin-alloys? the melting point of those isn't that high to begin with, and we have plenty of that in cheap quantities (it's also known as... solder).
Re:3D Print a Real, Metal Gun (Score:4, Interesting)
Why does everyone somehow seem to think that additive manufacturing ("3D printing") is better than subtractive (standard CNC)?
This blog post [reprap.org] should help out.
The materials gap is closing. Provided we actually get to a point where the physical properties of an additive object versus a subtractive object are no different, there won't be many compelling reasons to use subtractive anymore. At the very least, it'll be a question of whether you want to sweep up a bunch of sharp tailings every night or not.