Researchers Found a Way to Make "3D Printed Wood": The Results Are Stunning

When it comes to the materials that will be used to construct future cities, you’d think we could do a lot better than wood. After all, society graduated to stronger stone constructions about three or four millennia or so ago. But for reasons ranging from aesthetics to sustainability, wood may be about to make a come back.

For one, while it doesn’t contribute as directly to problems like deforestation, making concrete is a messy, emissions-heavy process: Mixing 1,000 so pounds of the stuff leads to about 1,000 pounds in corresponding emissions, too, according to one industry report. It’s also ugly.

Fortunately, a group of engineers working at Columbia University have developed a potential fix to both problems: “Digital wood” which can be created using a 3D printer. Their results are stunning in their own right, but, as they lay out the the most recent edition of 3D Printing and Additive Manufacturing, their new method may be what’s ultimately the most interesting finding in their research.

Why Make 3D Printed “Digital Wood”?

In their new paper, the authors describe a kind of playbook they say can essentially “photoshop” new materials to give them certain visual properties. The breakthrough here is that they showed this is possible with even “anisotropic” materials like wood, which are especially complicated to replicate because they contain different physical properties depending on which direction you approach them from (wood, for example, is stronger against the grain).

“While this work focused on digital reproducibility of wood, the same approach can be applied to many other anisotropic materials,” the researchers write. “Moreover, this study has shown the ability to ‘photoshop’ 3D structures to change color along with the potential for applying internal structures to arbitrarily complex shapes.”

Creating digital wood that actually looks like wood was no easy feat, and required a laundry list of techniques. First, to get a precise copy of wood’s visual properties, researchers used a process called destructive imaging where the wood was broken down into tiny samples and photographed. They then fed these images to a 3D printer, which converted them into 3D printer-ready ink using a dithering algorithm (dithering is an imaging technique where two differently-colored pixels are placed next to one another to create the appearance of a third color.)

The digital wood blocks were then printed using a Stratasys J750 printer, which uses a metal roller to smooth out the imperfections created by 3D printing using different materials.

It’s an interesting technique for a number of reasons, aesthetics aside. One of the main reasons 3D printing has failed to bring about the “new industrial revolution” predicted by its early adopters is that a 3D printer is only as useful as the materials you put into it; and the flimsy, cheap thermoplastic most commonly used in commercial 3D printing isn’t robust enough for many industrial uses. Developments like 3D printers which can handle metal, or techniques which can refine existing 3D printing ink, can change that.