Age-old 'Origami' method is renewed to produce intricate glass shapes

"When you fold a piece of paper, the level of complexity is somewhat limited, and 3D printing is kind of slow," Xie said in the press release. 

"So we wanted to see if we could combine these two techniques to take advantage of their attractive attributes. That would give us the freedom to make almost any shaped part."

A cross-linked polycaprolactone polymer, like raisins in raisin bread, was created by curing the mixture under ultraviolet radiation.

Then, using sheets of this translucent polymer combination, which has mechanical qualities akin to paper, Xu cut, folded, twisted, and tugged various shapes, including a crane, a feather, a lacy vase, and a sphere composed of entangled ribbons. 

When carried out at room temperature, the composite would maintain its altered shape throughout the rest of the manufacturing process. Xu found this was due to the stretching and folding process irreversibly disrupting the interface between some silica particles and the polymer matrix.

Furthermore, when folded and stretched, heating the composite at roughly 265 F permanently rearranges the linkages between the polymer chains, securely fixing the new shape.

A major challenge was achieving complete transparency

Xu discovered that removing the polycaprolactone polymer from the item and making it opaque requires a subsequent heating step at a temperature of more than 1,100 F. 

After cooling, melting the silica particles in a third heating stage called sintering at temperatures above 2,300 F enabled the item to transform into a transparent glass with a smooth, non-layered appearance.

The engineers described the project's major challenge as achieving that complete transparency. 

Xu is now working on extending the technique beyond the glass to ceramics and substituting silica for materials like zirconium dioxide and titanium dioxide. These substances allow for the creation of "functional" items that are less fragile and, in contrast to glass which is brittle and inert, have catalytic capabilities.

She highlighted that for large-scale manufacturing, her procedure could be automated. Ultimately, her team hopes that by spreading awareness of their study, the ceramics and artistic communities would use it to design sculptures and catalysts as well as other things the researchers haven't even considered.

Study abstract:

The art of origami has emerged as an engineering tool with ever increasing potential, but the technique is typically limited to soft and deformable materials. Glass is indispensable in many applications, but its processing options are limited by its brittle nature and the requirement to achieve optical transparency. We report a strategy that allows making three dimensional transparent glass with origami techniques. Our process starts from a dynamic covalent polymer matrix with homogeneously dispersed silica nanoparticles. Particle cavitation and dynamic bond exchange offer two complementary plasticity mechanisms that allow the nanocomposite to be permanently folded into designable geometries. Further pyrolysis and sintering convert it into transparent three dimensional glass. Our method expands the scope of glass shaping and potentially opens up its utilities in unexplored territories.