Origami robotics: Here’s how to fold your own ‘metamaterial’ at home

Origami: It’s not just art anymore. Engineers are harnessing the Japanese art of paper-folding to build in smarter, more efficient ways.

A team of researchers designed a self-folding robot that can assemble itself and crawl away in four minutes, described in the journal Science. But in the same issue, a second team shows how origami can be used to actually create materials with novel properties – and they show how you can create a ‘metamaterial’ of your own, right at home.

The study led by Jesse Silverberg of Cornell University applied origami-like principles of folding not to machines, but to the very materials they’re built from. After all, once you’ve produced a material – a rod of iron, a sheet of paper – it’s typically difficult to adjust its mechanical properties. But if your material is organized in a particular folding pattern, it could potentially be reconfigured at a moment’s notice.

So the scientists studied the Miura-ori – a pattern that basically looks like a 3D tessellation of parallelograms and is used to efficiently stack solar panels for space – to see how it responded to changes.

When the researchers folded paper into a Miura-ori pattern, it gave the paper an unusual springiness: When squeezed in the middle, it contracts evenly, instead of bulging out of the sides the way a sponge would. That’s a very useful property in a building material, from an engineering perspective.

They also found that they could adjust the stiffness – how much it resisted being squeezed – by introducing a defect in the pattern. All they had to do was take a finger and push out certain folds, creating what they called “pop-through defects,” and it would make the sheet stiffer. If they introduced more than one defect, they interacted in interesting ways, even canceling each other out.

On top of that, the defects were reversible – the folds could be popped back into place.

The scientists think this means that just about any thin sheet – whether paper, or different types of metal – can be converted into a metamaterial. And these kinds of origami-inspired materials, featuring ‘tunable’ properties, could be very useful for future soft robotics and other devices.

“Such structures would be self-folding and single or multifunctional, with applications for such capabilities as yet scarcely imagined,” Zhong You of Oxford University, who was not involved in the research, wrote in a commentary.

To see how you can make your own Miura-ori and test out different defects, check out the video above.

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