But if it's critical to fully retain the new shape during the subsequent steps, Xu found that the composite must be heated at about 265 F when it is folded and stretched. Xu discovered that's because the folding and stretching process irreversibly disrupts the interface between some of the silica particles and the polymer matrix. If she did this at room temperature, the composite retained its new shape fairly well throughout the remaining production steps. Next, Xu cut, folded, twisted and pulled on sheets of this translucent polymer composite, which has mechanical properties similar to paper, to make a crane, a feather, a lacy vase and a sphere made of intertwined ribbons, among other objects. Curing the mixture with ultraviolet light produced a cross-linked polycaprolactone polymer with tiny beads of silica suspended in it, like raisins in raisin bread. Yang Xu, a graduate student who works in Xie's lab at Zhejiang University, devised a technique in which she mixed nanoparticles of silica - the main ingredient for making glass - into a liquid containing several compounds. The team set out to see if they could overcome these shortcomings. In addition, the printed item usually has a layered texture that might not be the ideal appearance. And although 3D printing can do so, it's slow, and an object can be flimsy and need extra support while it's being made.

But a mold can't produce a complicated shape, Xie says. Typically, glass and ceramics are shaped in a mold or are 3D printed in the desired final structure. 'But we wanted to extend these techniques to glass and ceramics, which are much harder to process into complex shapes than polymers,' says Tao Xie, Ph.D., the project's principal investigator. In earlier work, the researchers used origami and the related technique of kirigami - which combines cutting with folding - to shape soft materials made of polymers.

The researchers will present their results today at the spring meeting of the American Chemical Society (ACS).

Glass 3d painting