Smart packaging

Researchers create spray-on ink which could have ‘huge potential’ for packaging

24-Oct-2019 - Last updated on 10-Oct-2019 at 10:16 GMT

The PhotoChromeleon. Photo: CSAIL MIT.

Researchers at the Computer Science & Artificial Intelligence Laboratory (CSAIL) at Massachusetts Institute of Technology, (MIT) US, have developed a spray-on ink that can change colors, designs, and patterns when zapped with different wavelengths of light.

The PhotoChromeleon which uses photochromic dyes, could have a huge potential for packaging as it can be applied to almost any object using standard painting methods like brushes or sprays.

UV light

The ink was created by mixing cyan, magenta, and yellow photochromic dyes together to create an ink that works like paint, but which is invisible until exposed to a specific light array.

Each dye reacts to different wavelengths of light, so by using three different light sources, the researchers could activate and deactivate three different ink colors to produce specific shades, complex patterns, and high-resolution images.

Once an object, such as packaging is coated with the ink, it’s placed in a box with a projector and a UV light.

The projector shines pre-determined images and patterns onto the object in different wavelengths to activate the colors in the ink, while the UV light resets the ink, essentially erasing all the colors and designs.

Depending on the size and shape of the object, and the complexity of the design being reproduced, the activation process can take anywhere from 10 to 40 minutes.

“This special type of dye could enable a whole myriad of customization options that could improve manufacturing efficiency and reduce overall waste,” said Yuhua Jin, lead author and postdoc graduate, CSAIL.

The CSAIL researchers are now looking to recreate photochromic dyes that match all the colors used in modern printing processes and to collaborate with material scientists to improve the color spectrum of the dyes which would open the product up to countless applications.

ColorMod

PhotoChromeleon comes off the back of another creation by the team of scientists called ColorMod, which uses a 3-D printer to fabricate items that can change their color. Frustrated by some of the limitations of the project, the team decided to investigate alternative applications.