Again, scientists are inspired in their work by nature – and very intense. The authors Yuhua Jin, Isabel Qamar, Michael Wessely, Aradhana Adhikari, Katarina Bulovic, Parinya Punpongsanon and Stefanie Mueller explain their latest work in "Photo-Chromeleon: Re-Programmable Multi-Color Textures Using Photochromic Dyes".
The Fascination Of the chameleon that has been preserved over the centuries, no one has yet been able to reproduce the magic of its color-changing skin. However, MIT's Informatic and Artificial Intelligence team is also using this phenomenon in 3D printing, developing a reprogrammable ink that changes color when exposed to UV rays and other light sources. The PhotoChromeleon system consists of a variety of dyes that are sprayed onto the surface of an object to change color as needed.
"By mixing cyan, magenta, and yellow (CMY) into a single solution and utilizing the different absorption spectra of each dye, we can control each color channel in the solution separately," the authors state. "Our approach can transform single-material manufacturing techniques such as coating into high-resolution multicolor processes."
We can create multi-color, reprogrammable textures from a single material. (a) We mixed photochromic CMY dyes together to make our multi-color ink. (b) After coating the object, we control each color channel pixel by pixel with (c) a UV light source and a projector, creating high-resolution multicolor textures that can be repositioned several times.  The potential for customization is exciting, allowing not only for use in natural environments (where color is retained after application due to its bistable nature), but also for other applications such as automotive paints, cell phone cases, and even fashion items such as shoes.
"This particular type of dye could provide a variety of customization options that could improve manufacturing efficiency and reduce overall waste," says CSAIL postdoc Yuhua Jin and lead author. "Users can personalize their belongings and appearance on a daily basis without having to buy the same object multiple times in different colors and styles."
(a) Mixed CMY inks produce a black that (b) corresponds to the CMY color model.
Starting with the latest ColorMod system, PhotoChromeleon ink can create complex patterns and even swirl landscapes in multiple colors. A UI creates drafts and patterns, and the program then transfers them to the object. Once an object has been coated and then placed under UV light, the colors range from transparent to "fully saturated" and can be desaturated as desired. The entire process takes 15 to 40 minutes for the user. Designs can be easily erased even with UV light.
"By giving users the autonomy to personalize their articles, countless resources have been spared and the ability to creatively change your favorite possessions is limitless," says MIT Professor Stefanie Müller.
There are currently limits to the color palette and, in some cases, researchers have to come to terms with getting as close to a particular color as possible. However, they plan to work with materials scientists to complete the entire color palette.
"We believe the incorporation of novel multiphotochrome inks into traditional materials adds value to Ford products by reducing the cost and time of manufacturing automotive parts," Dr. Alper Kiziltas, Engineering Specialist for Sustainable and Emerging Materials at Ford. "This ink could reduce the number of steps required to produce a multicolor part or improve the color's resistance to weather or UV degradation. One day, we might even be able to personalize our vehicles on a whim. "
Jin co-authored the paper with CSAIL postdocs Isabel Qamar and Michael Wessely. Former MIT UROP students Aradhana Adhikari and Katarina Bulovic, as well as MIT alum and current Assistant Professor of Engineering at Osaka University, Parinya Punpongsanon, and Stefanie Mueller award for their contributions to the project.
While this is a complex and useful system with potential for 3D printing enthusiasts around the world, nature has been mentioned as inspiration in a variety of projects from the production of conductive materials to recyclable liquid polymers parts, Replication of other complex structures and more. What do you think of this news? Tell us your thoughts! Join the discussion on this and other 3D printing topics on 3DPrintBoard.com.
(a) applying the photochromic coating and (b) the resulting coated object after UV activation.
The same shoe with two different textures to give the user a day outfit.