Need a pair of kicks to match an outfit? Perhaps you’d like to jazz up a tired-looking phone case? Changing patterns and colors can be difficult. But taking a cue from God’s amazing quick-change artists like chameleons, scientists are working to create nonliving objects that change color too.
Massachusetts Institute of Technology’s (MIT) Computer Science and Artificial Intelligence Laboratory has developed what it calls “reprogrammable ink.” The liquid is dubbed “PhotoChromeleon” after its lizard namesake. This high-tech ink changes color when ultraviolet (UV) light hits it. Even better: The process is completely reversible. It can be done over and over. Talk about reuse, recycle!
Yuhua Jin is the lead author on a paper about the PhotoChromeleon project. Yuhua says, “Users could personalize their belongings and appearance on a daily basis, without the need to buy the same object multiple times in different colors and styles.”
PhotoChromeleon could someday help customize just about anything from cars to clothes.
The process uses a mix of photochromic dyes. Photo means “light” and chroma means “color.” Users can create any pattern with it—from zebra prints to checked blocks.
The “magic” of PhotoChromeleon comes from a mix containing basic CMY printing colors: cyan (greenish-blue), magenta (pinkish-purple), and yellow. Different light wavelengths interact with the dye colors. By controlling the light, researchers control what color the dyes turn. According to MIT researchers, “if you use a blue light, it would mostly be absorbed by the yellow dye and be deactivated, and magenta and cyan would remain, resulting in blue,” and so on.
The scientists use a computer to map a design or image onto an object. (One test item was actually a toy chameleon!) They spray PhotoChromeleon onto the object and then place it inside a box. Projecting UV light onto the object activates the colors—and thereby the pattern.
Getting rid of the pattern is easy. Just hit the object with UV light again.
MIT Professor Stefanie Mueller says allowing users to customize belongings could save resources. Even more, the system allows for lots of creativity. Ford Motor Company agrees. Scientists at Ford have been collaborating with MIT on the color-changing project.
PhotoChromeleon “could reduce the number of steps required for producing a multicolor part,” says Ford technical specialist Alper Kiziltas. It could also “improve the durability of the color from weathering or UV degradation. One day, we might even be able to personalize our vehicles on a whim.”
