When we first got our Makerbot Replicator last year, I was really excited about the promise of using the dual-extrusion machine to make more complex prints. Why add a second print head? In the beginning, the ability to print multiple colors of plastic, without having to swap filament mid-print was compelling. And while I did manage to print a handful of test designs using black and white filament on the Replicator, the process to prepare models for a dual-head print involved splitting the different colored parts of a model into two separate STL files, making each of them printer-ready separately, merging them in ReplicatorG, and then adding a couple of additional steps to the already lengthy slicing process. It kind of sucked.

Enter MakerWare, Makerbot’s custom, mostly-closed source ReplicatorG replacement. While Makerware lacked dual-extrusion support at launch, it was added earlier this year. Since the update, I reconfigured our printer so it was running PLA on one head and ABS on the other—this makes printing using whichever material I want much more convenient. However, I hadn’t had a chance to test it out printing multiple colors on a single object using Makerware. I picked up a couple of fresh spools of ABS last weekend at MakerFaire, and figured that was as good an excuse as any to try dual-extrusion again.

My first multi-color attempt using Makerware was one of the gorgeous multi-color vases listed on Thingiverse (also pictured above). I set it up using the highest resolution setting, 0.1mm, which is what I usually use for prints today. Users of Makerware probably know that the Low and Medium print quality settings use MiracleGrue, Makerbot’s proprietary slicing engine, while the High quality setting uses ReplicatorG. MiracleGrue is dramatically faster than ReplicatorG, but it produces prints that are much lower quality (0.27mm vertical resolution vs. 0.1mm). I wanted to test both MiracleGrue and ReplicatorG with multi-color prints.

The difference in speed was quite remarkable.

It should only take two words to sell you on the idea of 3D printed food: "Pizza printer." Back in February we wrote about how 3D printers could be used to create the space foods of the future. Cornell's Fab@Home printer is already on the way, as it's able to build simple foods out of hydrocolloids. Of course, we're still a long way from the Star Trek Replicator, but even NASA's paying attention to the prospect of 3D printed food. The organization recently handed a $125,000 Small Business Innovation Research grant to Anjan Contractor to continue developing his prototype universal food synthesizer.

Star Trek's Food Replicator

Contractor's vision for 3D printed food is currently centered around space applications, but his eventual goal is to eliminate food waste here on Earth. "He sees a day when every kitchen has a 3D printer, and the earth’s 12 billion people feed themselves customized, nutritionally-appropriate meals synthesized one layer at a time, from cartridges of powder and oils they buy at the corner grocery store," writes Quartz. "Contractor’s vision would mean the end of food waste, because the powder his system will use is shelf-stable for up to 30 years, so that each cartridge, whether it contains sugars, complex carbohydrates, protein or some other basic building block, would be fully exhausted before being returned to the store."

The Small Business Research Innovation grant, though, is for a 3D printer that could supply food to astronauts on long trips. The International Space Station would welcome a food printer, most likely, but trips away from Earth's orbit, like a lunar colony or an expedition to Mars, would obviously benefit more. Powdered nutrients with 30 year shelf lives would be enormously valuable to astronauts setting up permanent shop on Mars.

And then, of course, there's the the pizza printer. Quartz writes "Contractor’s 'pizza printer' is still at the conceptual stage, and he will begin building it within two weeks. It works by first 'printing' a layer of dough, which is baked at the same time it’s printed, by a heated plate at the bottom of the printer. Then it lays down a tomato base, 'which is also stored in a powdered form, and then mixed with water and oil,' says Contractor. Finally, the pizza is topped with the delicious-sounding 'protein layer, which could come from any source, including animals, milk or plants."

Contractor won his grant thanks to his prototype 3D chocolate printer, seen above. It's not the only 3D printer we've seen lay down some chocolate goodness layer-by-layer, but it's the first we've seen that may lead to a 3D pizza printer. Godspeed, Anjan Contractor.

Last year, Formlabs raised almost $3 million on Kickstarter for its Form 1 3D printer, which we got a chance to see at World Maker Faire in New York. Unlike most desktop 3D printers, which melt and extrude plastic to form objects, the Form 1 uses stereolithography--basically, it cures a liquid resin with a laser, which can make for much higher resolution prints than extruded plastic. Now the Form 1 is finally shipping to its Kickstarter backers, and hardware expert Bunnie Huang already has his hands on one. Naturally, he immediately took it apart to see how it works.

Huang has written some cool teardowns on his blog in the past, like this look at how Chinese vendors can turn a profit on a $12 unlocked phone. When he took apart the Form 1, he noted how easy it was to disassemble with nothing but a 2.5mm hex key. That was the only tool he needed to take off the Form 1's orange plastic shield, which protects the eyes from the printer's blue laser and protects the printer's resin bath from ambient light, and to take apart the printer's base and frame.

Photo credit: Bunnie Huang

Once Huang had the Form 1 opened up, he walked through its various components. Here are some interesting tidbits about the Form 1's motors:

One of the big challenges for 3D printers is creating objects at a very fine resolution. MakerBot's Replicator 2, for example, can get down to 100 microns--that's great for a desktop 3D printer, but not as fine as (far more expensive) industrial 3D printers, which can print layers of 30 microns or less. The finer those layers get, the harder it will be to distinguish between a homemade 3D printed object and a factory-produced plastic thingamajig.

One of the most exciting advancements in 3D printing is all about detail at that micro level. Forget the finer detail of multiple 100 micron layers for a second--look at what Nanoscribe's 3D microprinter can put together at incredibly tiny scales. See these robots? They're less than a millimeter tall.

Printing at the nanoscale doesn't offer quite the same households benefits of a full-size 3D printer, but in the fields of science and medicine, it's enormously valuable. "Printing microstructures with features a few hundred nanometers in size could be useful for making heart stents, microneedles for painless shots, gecko adhesives, parts for microfluidics chips, and scaffolds for growing cells and tissue. Another important application could be in the electronics industry, where patterning nanoscale features on chips currently involves slow, expensive techniques," writes Technology Review.

Nanoscribe's claims its new microprinter, which it plans to sell later this year, is 100 times faster at printing microstructures than what is possible today. And that includes their current printer. Why is the new model so much faster?

Microprinters use a technology called two-photon polymerization, or, as Nanoscribe calls it, direct laser writing. It involves lasers:

Since we first read about the inkjet printer that spits out living tissue instead of ink for essays and birthday cards, we've been waiting for the day a 3D printer rises to the challenge of producing human flesh. There's precedent for 3D printing in the medical community: Just recently, a 3D printed implant was used to replace part of a man's skull. And now the inevitable's happened: Surprising Science posted a blog on Thursday about a 3D printer producing a material similiar to human tissue.

"Graduate student Gabriel Villar and his colleagues at the University of Oxford developed tiny solids that behave as biological tissue would. The delicate material physically resembles brain and fat tissue, and has the consistency of soft rubber," writes Surprising Science.

Villar's study explains that they used a specially designed 3D printer to print "tens of thousands of picoliter aqueous droplets," which isn't so unlike how a normal inkjet printer would operate. The difference, of course, is that the drops contain lipids, much like tissue. The drops are also absolutely tiny--a picoliter is one trillionth of a liter, and it's hard to appreciate how small these tissue arrangements are.

The structure of the printed tissue allows for electrical signals to travel across specific pathways like the neurons in brain tissue. The 3D printed material is hardly a replacement for real, living tissue at this point, but it's a step in that direction. The study notes "printed droplet networks might be interfaced with tissues, used as tissue engineering substrates, or developed as mimics of living tissue." 3D printed skin is coming. It's just a matter of time.