Origami Metamaterials Could Soften Impact Forces for Cars and Spacecraft

University of Washington  researchers have developed a metamaterial that uses “folding creases” to soften impact forces, and instead promote forces that relax stresses. The novel solution could have potential applications in spacecraft, cars, and more. “Metamaterials are like Legos. You can make all types of structures by repeating a single type of building block, or unit cell as we call it,” says Jinkyu Yang, UW associate professor of aeronautics and astronautics. The team's unit cell prototypes are made out of paper that connect together to form a chain.

Transcript

00:00:00 In my lab we work on designing and fabricating novel materials and structures. A large number of mathematicians and computer scientists, engineers, are working on origami nowadays. So imagine that you are going to use this origami structure as an impact protection layer and you are applying let's say, a hammer impact on one side. The compression wave will eventually change into a decompression wave while it's moving through this chain. So this video clip shows... at the beginning of the impact we have this red color formed due to the compression, but immediately after that we have a blue color due to the bouncing back motion of the origami unit cell. But what is interesting is

00:00:51 at a certain point we see the blue colour ahead of the red colour. What you are going to feel on the other side of the structure is that re-bouncing motion first, instead of the compressive force. So what you are going to feel on the other side is more like pulling motion instead of compressive motion. The applications can be abundant- for example, delivering a package using a drone. You want to protect your medium from the impact from the ground. Another example can be a landing structure. We can convert compression to tension so your whole structure can be well protected against the impact.

00:01:34 When I have visitors from outside and they look at this variety of origami, they are just amazed to see how this interesting origami can be integrated into state-of-the-art research. When we were starting this project the mechanism seemed so counter-intuitive, so we were so excited so thrilled because we were not even sure this can really happen.