American engineers have devised a fabrication method based on the Japanese art of origami that enables the creation of extremely sturdy structures from very thin materials, including paper.
The method, which the researchers call ‘zippered tube’ configuration, allows the structures to be easily folded for transport.
Structures from plastic or metal could be built using the method which opens a wide range of applications including pop-up furniture, construction cranes that can fold, robotic arms or quick assembling emergency shelters or bridges.
"Origami became more of an objective for engineering and a science just in the last five years or so," said Evgueni Filipov from the University of Illinois at Urbana-Champaign who worked on the project together with colleagues from the Georgia Institute of Technology and the University of Tokyo.
"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."
The researchers are using a particular origami technique called Miura-ori folding. They make precise, zigzag-folded strips of paper and then glue two strips together to make a tube. While the single strip of paper is highly flexible, the tube is stiffer and does not fold in as many directions.
The researchers tried coupling tubes in different configurations to see if that added to the structural stiffness of the paper structures. They found that interlocking two tubes in zipper-like fashion made them much stiffer and harder to twist or bend. The structure folds up flat, yet rapidly and easily expands to the rigid tube configuration.
"The geometry really plays a role," said Georgia Tech professor Glaucio Paulino. "We are putting two tubes together in a strange way. What we want is a structure that is flexible and stiff at the same time. This is just paper, but it has tremendous stiffness."
The zipper configuration works even with tubes that have different angles of folding. By combining tubes with different geometries, the researchers can make many different three-dimensional structures, such as a bridge, a canopy or a tower.