Throw it a curve and 2D becomes 3D

Researchers in Austria have developed a computer program that can generate a flattened template, or layout, from a given 3D model. The 2D net itself can be printed as a flat object for much easier packing and transportation, but when release it curves up into the 3D object it was always intended to be. Details will be presented by scientists from the Institute of Science and Technology in Austria at this year's "SIGGRAPH" conference.

3D printers have existed since the 1980s, but the full potential of this technology is yet to be fulfilled entirely. An active area of research is the creation of "self-actuating" objects: flat materials that can be, with a physical nudge, transform into the original 3D design, the notion is akin to the concept of a pop-up tent or perhaps instantaneous origami. Until now, such successes as there have been in making 2D objects that fold into 3D objects has required that the final 3D object have sharp edges and very little, if any, curvature. The transformation methods have primarily involved chemically-driven folding or inflation.

Now, for the first time, a group of current and former IST Austria computer scientists has created self-actuating, smooth, free-form objects, which they've named "CurveUps". Ruslan Guseinov, Eder Miguel, and Bernd Bickel developed the computational tools to make a 2D net from the 3D printer computer model. "I experimented with so many different materials and methods before coming up with our current design," explains Guseinov. CurveUps are made up of tiny tiles sandwiched between pre-stretched latex layers. During the transformation process, the tension in the latex pulls the tiles together joining them into a continuous shell.

Given that even the smallest 3D model would be represented by hundreds if not thousands of individual tiles, the computation is a significant optimization problem. One that would not be possible with a conventional computer. The team thus implemented a two-step optimization procedure wherein a first approximation is obtained and then local refinements carried out before producing the final template.

"Our research is a step toward the development of new fabrication technologies: there have been many advances in flat fabrication, for instance in electronics, that have previously been limited to 2D shapes," Guseinov explains. "With CurveUps, we make it possible to produce 3D objects empowered with these same technologies, pushing the limits of digital manufacturing far beyond the current state."

Guseinov told Materials Today that the team plans to carry on working in the area of self-actuating objects. He mentions four exciting directions the research might go: "Making this mechanism work with any rigid material (or at least a much wider range then 3D printed plastic); this could be developed as an alternative method of fabrication to the existing printers (if we manage to eliminate 3D printing in our fabrication pipeline); we are interested in improving the mechanism to make it fully controllable (e.g. in which order each part of the object actuates); since not any shape is reproducible, we are interested to develop a framework for designing CurveUps in an easy and intuitive way.

David Bradley blogs at Sciencebase Science Blog and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".