3D-printed objects change color on demand

Credits: www.newatlas.com

Scientists there have created a new system that allows the color of 3D-printed objects to be changed repeatedly, after they’ve been created.

The system is known as ColorFab, and here’s how it works …

When items are printed using the new technology, they’re made up of voxels (three-dimensional pixels) that incorporate either red, yellow or blue light-sensitive dye. All of the voxels take on their colors when the object is exposed to ultraviolet light. Even after being removed from the UV light, all of the voxels remain “switched on,” so the object is a mosaic of red, yellow and blue.

The dye, however, can be “switched off” and made transparent when exposed to sufficiently-intense visible light. With this in mind, after all of the voxels have been switched on using UV light, some of them are then selectively switched off by projecting a pattern of visible light onto the object.

If all of the red and yellow voxels are switched off, for instance, only the blue ones will remain colored, causing the item to look blue. Although the resolution of the system is still fairly coarse, it is hoped that once it gets finer, colors other than the three primaries could be created – by only switching on the yellow and blue voxels, for example, the result would be an object that appeared green.

While the whole color-changing process currently takes 23 minutes, the scientists believe that they could bring that figure down by using a more powerful projector, or incorporating a greater amount of dye. Additionally, although the technology has so far been limited to producing plastic items, it may ultimately be possible to manufacture ColorFab clothing.

“Largely speaking, people are consuming a lot more now than 20 years ago, and they’re creating a lot of waste,” says assistant professor Stefanie Mueller, who led the research. “By changing an object’s color, you don’t have to create a whole new object every time.”