There is now proof that it is possible to fold an origami structure that is about the same size of a penny. Bok Yeop Ahn, postdoctoral researcher, came up with the idea to create these new printed origami structures through direct ink writing, he said.

Direct ink writing is a technology that works to create 2-D or 3-D structures.

It is a linear-dimension-based printing method where a concentrated ink is extruded through a tapered cylindrical nozzle, Ahn said.

The movement of the nozzle is programmed in the computer and then the nozzle produces the pattern. Ahn then uses wet-folding oragami techniques to create the 3-D structures.

There are several different materials that may be used when building this structure including metallic, ceramic or polymeric inks, Ahn said.

“The process involves combining a direct-write assembly with a wet-folding origami technique to create 3-D shapes which are then transformed to metallic and ceramic structures by thermal annealing,” Ahn explained.

Thermal annealing is a process where metals go through a heat treatment, causing the metal properties to change.

During the process, one of the problems the group discovered was that the structure was somewhat brittle and not ductile enough, Hansen said.

“The material needs to be the right consistency so that it does not break when folding, and it also is able to stand on its own,” Hansen said.

The 3-D objects that the group assembles can be used for applications with biomedical devices and other medical technologies, Ahn said.

Chris Hansen, Daisuke Shoji and Eunji Hong are also part of the research team. Hansen, a graduate student in materials science and engineering, carried out background mechanical testing during the process, he said.

The group was asked by Professor David Dunand from Northwestern University to revise the planar structures, Ahn said.

Professor Jennifer Lewis, from the department of materials science and engineering, worked with Dunand in defining the initial project, she said. She also provided guidance to the team and contributed to writing up the work that was published.

Part of this project was creating a written lab report that includes the whole process of how the structures are created, what the group used and all of the little details that go into it.

Ahn would like to continue working with this process and to improve the sizing of the structures.

“We hope to optimize the ink system for better mechanical proportions,” Ahn said.

The structures could go on a mega scale where the needle size would be increased, Hansen said.

The possibility of aerospace applications would be available with these larger models.

There is also a direction for a minimal scale, where the products produced would be even smaller than the ones produced now, Hansen said.

The write-up that Ahn developed is going to be published in the science magazine “Advanced Materials” in their twentieth issue as the cover story.

It also is currently out online, which became available on April 14.

Taking this unique approach to origami has proved to be successful for the group.

“I am simply delighted by the outcome of this work,” Lewis said. “It is a terrific example of creativity combined with cool science.”