New technique lets you fold flat metal or plastic into a 3D shape

A computational design tool created by researchers at Carnegie Mellon and the Swiss Federal Institute of Technology lets you fold a piece of metal or plastic into a “complex 3D shape” like a mask or even a shoe.

“We’re taking a flat piece of material and giving it the tendency, or even the desire, to bend into a certain 3-D shape,” said Keenan Crane, part of the Carnegie Mellon team.

By making hexagonal cuts into flat materials the team is able to let the pieces expand uniformly allowing them to create, say, a sphere from a rigid piece of plastic.

Origami-style techniques are already in use in deep space solar arrays and arterial stents. However this technique lets fully 3D objects to spring forth from a piece of plastic.

This means you can make something like a wild 3D dress out of metal or a car piece out of plastic with a few well-placed cuts. Write the researchers:

Metal and plastic sheets, altered with cuts to lend them auxetic qualities, are convenient materials to explore how to create these complex designs, Crane said. In this study, a series of hexagonal slits were cut into the sheets to create triangular elements that were able to rotate relative to their neighbors, allowing them to expand uniformly.

Based on a 3-D digital model, the computational tool can determine the pattern of slits necessary to make the sheet conform to the desired shape. This pattern can then be transferred to a laser cutter to begin the fabrication process. The researchers used this process to make a woman’s high-heel shoe, a sculpture, a woman’s fashion top, a lampshade and face masks.

The next step, say the researchers, is to create a way to map 3D objects for easy printing and to ensure that objects pop into place automatically when folded slightly.