3-D printers haven't bum-rushed our daily lives like the hype suggested they might. But don't let the fact they aren't a living room staple suggest the technology isn't progressing in invigorating ways. Take, for instance, MIT's MultiFab, which can create fully functional, multi-material devices in a single run, with greater variety and lower cost than similar devices.

There have been plenty of 3-D printers that have an array of materials at their disposal. But the MultiFab distinguishes itself not just through its low cost, but also the clever software it uses to achieve its results.

"The multi material 3-D printers available out there are insanely expensive," says Javier Ramos, reasearch engineer on the MultiFab team. "And they're very limited in the number of materials they can print and the software accessibility. So we decided to build our own multi-material 3-D printing platform, with the idea that we're going to make it inexpensive, and a software platform that we would keep open and hackable."

The MultiFab was thrown together with roughly $7,000 of off-the-shelf parts.

Just how pricey is the competitive set? In a paper (.pdf) outlining its findings, Ramos's team points to the Stratasys Objet Connex, which runs a cool $250,000. By contrast, MultiFab was thrown together using roughly $7,000 in off-the-shelf parts. Even more remarkable? The MIT group accomplished those savings without sacrificing quality. In fact, the team did it by applying some good old fashioned software smarts.

"A big part of the ability to reduce the cost is the 3-D scanning module," Ramos says. "More expensive printers have this mechanical system that sweeps every layer and makes sure it's flat and properly laid out. We don't need those extreme mechanical tolerances for this mechanism given that we use this machine vision system, which is non-contact. It scans the layer and corrects the layer, so we don't need these very expensive mechanical components."

That machine vision technique, combined with less durable but far cheaper off-the-shelf printheads, accounts for the impressive savings. It's also arguably MultiFab's most important breakthrough.

"There's a lot of 3-D scanners out there," Ramos says. "But we quickly realized that's not a solution, mostly because of the nature of the materials that we're using and the resolution that we need to scan. The scanner we developed solves a few high-level problems, which are very high resolution, being able to scan a large area quickly, and then being able to scan materials that are transparent or have some translucency. Those are historically very hard materials to scan."

The ability to handle a wide variety of materials comes in handy when you're printing with up to 10 of them at a time. The MultiFab can handle everything from lenses to fabrics to fiber optics bundles to complex meta-materials, with applications ranging from scientific to aesthetic. In many cases, it spews out improved versions of existing 3-D printing achievements; full-color 3-D printers already exist, for instance, but MultiFab appears to be the first do so without requiring any post-processing.

The real-world applications are as diverse as the materials used. Ramos notes that movie studios and production designers may have a keen interest in more accurate, full color scale representations. Architecture and auto design are two other fields that come to mind, though the applications are as limitless as the materials. Besides, the most exciting stuff is what's coming next.

"The real holy grail of all this multi-material printing is combining functional materials, and that's where we're headed. We want to combine materials that have functional properties either mechanically, which is what we've demonstrated, optically, or semiconducting," Ramos explains. Instead of piecing Voltron together, you could print it in one go.

MultiFab isn't without its limitations. It's slow, for starters; while a smartphone-friendly, custom-sized privacy screen takes an hour, a more complex, multi-color mini-tire takes nearly a day and a half to materialize. The type of scanner it employs struggles with certain types of surfaces, like mirror finishes. And while the printing resolution is certainly high, it could be even higher with a more expensive printhead. Then again, you'd lose some of that significant cost advantage.

So yes, it's disappointing that 3-D printing in the home hasn't moved much past the make-your-own-spork phase. Rest assured, though, that it's getting better every day, with applications that will shape your world in multiple, material ways.