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Let’s say you lose the key to your house. Oh no. Now you can’t leave the house without leaving your door unlocked, at which point you may as well just invite the robbers in yourself. Well, let’s also say that you’re in the future. The near future, not the one where HG Wells predicted we’d all look like weird alien things that hop around on three legs. So, what with it being the future and all, you have access to future technology in the form of a little device that looks kind of like a microwave. You put a little cylinder of jelly no bigger than a coffee cup into it, closing it up and withdrawing a flash drive (or whatever else we’ll be using at the time) from your pocket. On this flash drive is a model of your poor, misplaced key. You plug the thing in and it tells you to give it ten minutes. Lo and behold, ten minutes later, there’s your house key.
3D printing re-envisioned
Yes, 3D printing is already a thing, I know. But there are flaws with it that can’t be overlooked: it takes too long, it costs too much, and it screws up the surface of whatever you’re trying to print. This is incredibly inefficient, and because we’re humans, we want to innovate on it in every way possible until there’s no other way to innovate. This is a new type of 3D printing that looks like it’s making an object spontaneously materialize out of nowhere, and it’s showing much more promise than the current generation of 3D printing. Rather than taking its sweet time— hours, if not days to produce a full model— this thing gets it done in a matter of minutes. So what’s the secret? Good ol’ fashioned light and some wildly expensive, high-tech jelly. Combine these two and you’ve got a recipe for success prepared to take the 3D printing world by storm.
Brace yourself for some science words: this new form of printing is being called “computed axial lithography.” The idea is that, rather than printing an object layer by layer (like most current forms of 3D printing), the entire object is slowly created all at once. Every detail of it, fading into reality simultaneously like a much less impressive version of a replicator from Star Trek. Perhaps the coolest thing about this technology is just watching it do its job: the object looks like it’s quite literally materializing out of thin air. So, how exactly does shooting a bunch of light into jelly produce this effect? Well, it’s a very intricate and complicated process involving lots of images, spinning things, projectors and tiny statues of The Thinker. Let’s take a look.
Becoming the thinker
The process starts with taking a 3D scan of an object. That is, take a whole boatload of pictures of an object from every conceivable angle, and upload them as images into a computer. Once this is complete, the images are prepared to be projected using… well… a projector. That’s right, just a regular projector. Then, a cylinder of translucent jelly (or rather, just a very viscous liquid) sitting in a transparent container is placed on a rotating platform, right in front of the projector. Simple enough? Well, I wish it stayed that way: this canister needs to rotate at such a speed that it lines up exactly with the images being flipped through on the projector. One of the things printed was a tiny version of The Thinker statue. So the canister rotates, while at the same time, a tiny version of The Thinker rotating is projected into the jelly.
Oh, don’t worry: it only gets more complicated from here. This jelly, as I’ve mentioned before, isn’t your average jelly. It’s a photosensitive substance: meaning that it changes in reaction to photons. Basically, light makes it do things. In the case of this substance, light makes the material harden into a shiny, translucent plastic. This won’t happen with just any amount of light, however: there’s a threshold that must be hit in order to make the magic happen. The light is beamed into the substance from the projector while it spins; this spinning motion ensures that the light is bound to penetrate the center of the substance perpetually, while the area behind and in front of the center continues changing. This makes it so that only the center, where all of the light is overlapping, is the only part of the material that hardens.
You can relax now
Phew. I don’t actually expect you to get all of that, but if you did, give yourself a firm pat on the back. If you didn’t, don’t worry: all you need to know is that this means you can turn liquid into plastic with light, and that’s exactly what scientists are doing. Along with this, the team was also able to find a way to print objects over existing 3D objects: like a plastic handle over the metal rod of a screwdriver.
Currently, however, the technology is still very much in its infancy. They haven’t been able to produce anything over a centimeter in length, and what they do produce related to more complex geometry (like the aforementioned tiny Thinker) is seemingly jagged and irregular. With a bit more revision, however, this technology could very well lead to a much better solution for 3D printing fanatics. And who knows: maybe one day, we’ll all have little microwave-looking 3D printer devices in our offices.