Researchers at the University of Washington in the US developed a prototype of a metamaterial inspired by the Japanese art of paper folding to soften the blow on a rocket’s legs during landing.

Landing is a stressful event on a rocket’s legs, because they must handle the force from the impact with the landing pad. To combat this, the researchers set out to find a way to absorb some of the force and soften the blow.

The result is a paper model inspired by origami, the Japanese art of paper folding. This technique has been used in a lot of research lately. The metamaterial has folding creases marked by laser-cut dotted lines, and a cylindrical structure with acrylic caps on either end to connect the cells into a long chain.

The researchers lined up 20 cells and connected one end to a device that pushed and set off a reaction throughout the chain. The compression wave was tracked with cameras, as well as the tension wave as the unit cells returned to normal. Even though the compressive pushing force started the reaction, the force never made it to the other end of the chain. Instead, it was replaced by the tension force that started as the first unit cells returned to normal and propagated faster and faster down the chain. The unit cells at the end of the chain only felt the tension force pulling them back.

In addition to softening rocket landings, the metamaterial could be used for cars and other impact-prone applications.

Photos: Kiyomi Taguchi/University of Washington