Home https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Science https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ A flash of light changes the colors and patterns of objects

A flash of light changes the colors and patterns of objects


A new system uses UV light projected on objects coated with light-activated dye to change the reflective properties of the dye and create images in minutes. Credit: with permission of the researchers

“Programmable matter”

; technology could enable product designers to easily replace prototypes.

When was the last time you painted your car again? Redesigned your collection of coffee mugs? Did your shoes give a colorful facelift?

You probably answered: never, never and never. You may consider these difficult tasks not worth doing. But a new color-changing “programmable fabric” system could change that with a candle.

WITH researchers have developed a way to quickly update images on object surfaces. The system, called “ChromoUpdate”, pairs an ultraviolet (UV) light projector with objects coated in light-activated dye. The projected light changes the reflective properties of the dye and creates colorful new images in minutes. Advances could accelerate product development, enabling product designers to run through prototypes without getting stuck in paint or printing.


An ultraviolet (UV) light projector is used on a mobile phone case coated in light-activated dye. The projected light changes the reflective properties of the dye and creates images in minutes. Credit: with permission of the researchers

ChromoUpdate “benefits from fast programming cycles – things that had not been possible before,” says Michael Wessley, lead author of the study and a postdoc at MIT’s Computer Science and Artificial Intelligence Laboratory.

The research will be presented at the ACM Conference on Human Factors in Computer Systems this month. Wessely’s co – authors include his advisor, Professor Stefanie Mueller, as well as postdoc Yuhua Jin, recent graduate Cattalyya Nuengsigkapian ’19, MNG ’20, guest student Aleksei Kashapov, postdoc Isabel Qamar and Professor Dzmitry Tsetserukou from the Skolkovo Institute of Science. and technology.

ChromoUpdate is based on the researchers’ previously programmable material system, called PhotoChromeleon. This method was “the first to show that we can have high-resolution multicolor textures that we can just reprogram over and over again,” Wessely says. PhotoChromeleon used a lacquer-like ink consisting of cyan, magenta and yellow dyes. The user covered an object with a layer of ink, which could then be reprogrammed using light. First, UV light shone from an LED on the ink and fully saturated the dyes. Then, the dyes were selectively desaturated with a visible light projector, which brought each pixel to the desired color, leaving the final image. PhotoChromeleon was innovative, but it was sluggish. It took about 20 minutes to update an image. “We can speed up the process,” says Wessely.

They achieved this with ChromoUpdate by fine-tuning the UV saturation process. Instead of using an LED that uniformly blasts the entire surface, ChromoUpdate uses a UV projector that can vary light levels across the surface. So the operator has pixel level control over saturation levels. “We can saturate the material locally in the exact pattern we want,” says Wessely. It saves time – someone designing a car’s exterior might just want to add racing stripes to an otherwise finished design. ChromoUpdate lets them do just that without deleting and re-exposing the entire exterior.

This selective saturation procedure allows designers to create a black-and-white preview of a design in seconds or a full-color prototype in minutes. That means they could try dozens of designs in a single work session, a previously unattainable feat. “You can actually have a physical prototype to see if your design really works,” says Wessely. “You can see what it looks like when the sunlight shines on it or when shadows are created. It is not enough just to do this on a computer. ”

This speed also means that ChromoUpdate could be used to deliver real-time messages without relying on monitors. “An example is your coffee mug,” says Wessely. You put your mug in our projector system and program it to show your daily schedule. And it updates itself instantly when a new meeting comes that day or it shows you the weather forecast. ”

Wessely hopes to continue to improve the technology. At present, the light-activated ink is specialized for smooth, rigid surfaces such as mugs, telephone boxes or cars. But researchers are working towards flexible, programmable textiles. “We’re looking at methods to dye fabrics and potentially use light-emitting fibers,” says Wessely. “So we could have clothes – t-shirts and shoes and all that – that can reprogram themselves.”

The researchers have partnered with a group of textile manufacturers in Paris to see how ChomoUpdate can be incorporated into the design process.

Reference: “ChromoUpdate: fast design teration of photochromic color structures using grayscale preview and local color updates” by Michael Wessely, Yuhua Jin, Cattalyya Nuengsigkapian, Aleksei Kashapov, Isabel PS Qamar, Dzmitry Tsetserukou and Stefanie Mueller.

This research was partially funded by Ford.

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