Kirigami: Japanese art form helps create new lightweight material

23 Aug 2023

Image: Courtesy of the researchers

Described as akin to ‘steel cork’, plate lattice developed by a team of MIT scientists can help create strong and light parts for planes, cars and spacecrafts.

Scientists have created a strong new type of metal-based material based on kirigami – an ancient Japanese art form of folding and cutting paper – which is lighter than cork.

Like the more popular origami, kirigami is the practice of folding and cutting paper to create 3D shapes that are light and firm. By replacing paper with metals, scientists hope this so-called architected material can have customisable mechanical properties.

“This material is like steel cork,” said Prof Neil Gershenfeld, who leads the Center for Bits and Atoms at Massachusetts Institute of Technology (MIT) and is senior author of a new paper on this approach. “It is lighter than cork, but with high strength and high stiffness.”

Known as plate lattice, the material has been built on a much larger scale than scientists have previously been able to achieve by additive fabrication. The custom shapes allow scientists to render metals or other materials new mechanical properties.

The paper was presented at the International Design Engineering Technical Conferences and Computers and Information in Engineering Conference in Boston this week.

“Plate lattices outperform beam lattices in strength and stiffness while maintaining the same weight and internal structure,” said Alfonso Parra Rubio, one of the paper’s co-lead authors.

“[Its] construction has been so difficult that there has been little research on the macro scale. We think folding is a path to easier utilisation of this type of plate structure made from metals.”

Others behind the paper include Klara Mundilova, an MIT electrical engineering and computer science graduate student, David Preiss, a graduate student at MIT and Erik Demaine, an MIT professor of computer science.

Lightweight lattices

Using the method, the team produced aluminium structures with a compression strength of more than 62 kilonewtons, but a weight of only 90 kilograms per square metre. In contrast, cork weighs about 100 kilograms per square metre.

The team found that the structures were so strong, they could withstand three times as much force as a typical aluminium corrugation. This means the technique could help scientists produce more lightweight and shock-absorbing components for planes, cars and spacecraft.

“To make things like cars and airplanes, a huge investment goes into tooling. This manufacturing process is without tooling, like 3D printing,” Gershenfeld explained. “But unlike 3D printing, our process can set the limit for record material properties.”

But the method using kirigami plate lattice structures can be difficult to model.

“In my experience producing complex architectural projects, current methods for constructing large-scale curved and doubly curved elements are material intensive and wasteful, and thus deemed impractical for most projects,” said James Coleman, co-founder of design for fabrication and installation firm SumPoint.

“While the authors’ technology offers novel solutions to the aerospace and automotive industries, I believe their cell-based method can also significantly impact the built environment,” he added.

Coleman, who was not involved with this work, thinks the ability to fabricate various plate lattice geometries with specific properties could enable higher performing and more expressive buildings with less material.

“Goodbye heavy steel and concrete structures, hello lightweight lattices!”

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Vish Gain is a journalist with Silicon Republic