An international team of researchers has developed a new structural engineering methodology that derives its chief inspiration from the traditional Japanese art of paper folding.
The “zippered tube” structure developed by researchers from the University of Illinois at Urbana-Champaign, the Georgia Institute of Technology and the University of Tokyo possesses sufficient strength to bear significant loads even when made using sheets of paper material.
According to University of Illinois graduate researcher Evgueni Filipov, the zippered tube takes its inspiration from Japanese origami – a traditional paper folding art whose underlying structural engineering principles have recently emerged as a topic of interest among scientists and academics.
“Origami became more of an objective for engineering and science just in the last five years or so,” said Filipov. “A lot of it was driven by space exploration, to be able to launch structures compactly and deploy them in space.”
The tubes themselves consist of two zigzagging strips of paper that are glued together to enhance their stiffness. Two or more of the tubes can then be combined in a zipper-like interlocking manner in order to produce a structure of heightened resilience and strength.
Because each of the zippered tubes is made from a thin flexible sheets, they can be folded back into a flat structure for highly convenient transportation and storage. They can also be readily expanded back into their distended, tube-like configurations.
“The geometry really plays a role,” said Georgia Tech professor Glaucio Paulino and former Illinois professor of civil and environmental engineering. “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.”
Zipper tubes with different folding angles can also be combined together in different permutations in order to produce a variety of three-dimensional structures that could lend themselves to a number of different purposes, potentially serving as horizontal bridges or high-rise towers.
“The ability to change functionality in real time is a real advantage in origami,” said Filipov. “By having these transformable structures, you can change their functionality and make them adaptable.
“You can change the material characteristics: you can make them stiffer or softer depending on the intended use.”
While the prototypes have followed the lead of their origami inspirations in using paper sheets, any other thin materials could also be used to make the structures, including plastic or metal, in order to produce sturdier structures that could serve any one of a number of engineering applications – including enhancing the speed and convenience of prefab construction.
“We’re starting to see how it has potential for a lot of different fields of engineering,” said Filipov. “You could prefabricate something in factory, ship it compactly and deploy it on site.”