A new generation of meta-materials are emerging from a 17th century source.
That's the gist of a new paper in the Proceedings of the National Academy of Sciences, where a trio of engineers describe an entirely new form of origami that they say turns a simple piece of paper into a structure more than two orders of magnitude stronger than itself.
"Origami engineering has really taken a leap in the last few years," says co-author Evgueni Filipov, a PhD student at University of Illinois. Filipov says that their system could change how we build spacecraft, how buildings and bridges are designed, and even how shipping companies operate — and it came out of a lab that makes only paper models.
Their pattern is called a "zippered tube," and it relies on a newer idea in origami called Miura-ori, or Miura folding. Miura folding is a great way to take a sheet of paper and fold it down into a very tiny piece of paper — it was actually thought up by a Japanese astrophysicist in the 1980s, Koryo Miura. Miura was imagining a way to robotize the process of folding up solar arrays into a very small space before and after they're launched into space — the design he came up with is still influencing NASA today.
Anyways, Muira's pattern is common today, and it forms the basis for the zipper tube. But take a single folded piece. It might bends pretty much any direction when force is applied, even directions you might not intend, as this GIF demonstrates:
But you can make that piece much more stiff, and resistant to that bending, if you glue a second piece on to create a tube.
You can even start adding more individual tubes together, creating an even stiffer structure that can still fold flat in the way you intend it to:
Look ma, no bending!
You can see a similar idea at work in some skyscrapers, like the Willis Tower, which is structured around nine individual tubes that together create structural stiffness against pressure to "bend" laterally against wind or seismic forces. In the case of these researchers' zippered tubes, they're designed to move — but only in pre-described ways dictated by their folds.
The trio took that simple idea and complicated in with dozens of sheets and tubes, creating super-complex structures that look almost honeycomb-esque, and can hold an amazing amount of weight while still being flexible.
While very cool, this is just one example of a genre of engineering that's seen a bit of a boom lately. There are whole conferences devoted to the development of new ideas in origami by scientists and engineers. NASA turned to origami to design its latest deployable solar array.
Here's how Filipov explains it:
Origami became more of an objective for engineering and a science just in the last five years or so. A lot of it was driven by space exploration, to be able to launch structures compactly and deploy them in space. But we're starting to see how it has potential for a lot of different fields of engineering. You could prefabricate something in a factory, ship it compactly and deploy it on site.
These structures are so cool because they're changeable — after centuries of resorting to heavy, permanent materials to build strong systems, we're seeing a new generation of materials that are strong, but not unmoving.