MIT Creates Light-Sensitive ‘Reprogrammable’ Ink

You probably had to agonize over colors the last time you bought a car, a pair of shoes, or anything else where color matters. What if you didn’t have to pick a single color, though? Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have developed a new color-changing ink that you can “reprogram” with light to produce different colors and patterns. Best of all, you can change the colors as many times as you want.

MIT calls this “PhotoChromeleon” ink, and it’s a mix of multiple polychromatic dyes that can be spray-painted on almost any object. The team started by mixing standard automotive lacquer with cyan, yellow, and magenta polychromatic dyes. Each individual dye changes color when exposed to UV light.

When you mix all three dyes together, you have a paint that can produce a wide range of colors. By understanding how each dye reacts to light, the researchers are able to precisely control each color channel. It’s similar to the way a modern inkjet printer uses individual cartridges of cyan, magenta, and yellow ink to create almost any shade you want.

The team tested the programmable ink on various objects like a show, a phone case, and a (quite fittingly) a toy chameleon. The video below demonstrates how the clear ink becomes DLP projector shines high-intensity light onto the object’s surface as it spins on a turntable. However, it does take a few hours to create a pattern on small objects in the lab. The result is a colorized layer that looks like it was painted on. It was in a sense, but you can change the paint job whenever you want.

This system is an evolution of ColorMod, a previous MIT experiment that used a 3D printer to create objects that could change color. In that case, the printer had to create each “pixel,” so the resulting patterns weren’t very clear. PhotoChromeleon produces crisp images, and you can quickly “reset” the ink with an ultraviolet light.

MIT believes PhotoChromeleon technology could eventually make manufacturing more efficient and reduce waste. Imagine that you didn’t need to get two different pairs of shoes in different colors. You could just reset the color and change it to something else whenever you want. Bored with your phone case? Don’t buy a new one, just change the pattern with light. MIT is already working with Ford to advance the PhotoChromeleon project, which also supported the development of ColorMod.