A new system uses ultraviolet light to reprint colors and designs onto objects, allowing artists and developers to quickly preview their creations and test new ideas on tangible items rather than through a digital interface alone.

The invention, which can easily erase colors and textures and overwrite new ones on a wide variety of surfaces, will be detailed in a May 12 presentation at the Association for Computer Machinery's Special Interest Group on Computer-Human Interaction Conference. The technology, known as "ChromoUpdate" and also described in a paper published in conjunction with that conference, was developed by a team of researchers at the Massachusetts Institute of Technology and the Skolkovo Institute of Science and Technology.

"This work is bringing features that previously only existed in the digital realm to the physical world," Michael Wessely, a researcher at MIT's Computer Science and Artificial Intelligence Laboratory and the study's lead author, told The Academic Times. "So instead of being only able to try out different designs quickly — in a few seconds or so — on a computer, you can now do this in the physical world with our system by reprogramming the appearance of objects."

ChromoUpdate offers a more immersive design experience than is currently possible on a two-dimensional screen, according to Wessely and his colleagues. Three-dimensional design software can rarely show a completely accurate representation of what a particular color or texture will look like in the real world, but, "When you have a real object, you can actually try it out in your own hands," Wessely said. This extends to testing the objects in different environments — even outside under natural lighting conditions, for instance. Beyond its utility for designers and other professional creators, the technology may also serve as an accessible tool for customers to build and customize attire and accessories to match their personal preferences.

In the system, a UV projector shines light for varying lengths of time onto an object that has been sprayed with a special paint. Although the paint is clear, it can change colors depending on its level of exposure to different amounts of UV light. The paint consists of three separate bases — cyan, magenta and yellow — that can be combined in different shades and concentrations to create a wide array of colors, similar to how many printers use a trio of ink cartridges to produce a colored image. This iteration of the system works as a plugin for Blender, a popular 3D image editing software where designers can develop a digital creation and apply it to a variety of 3D surfaces. Users then place a particular object on a rotating platform situated in front of the UV projector "and let the software do the work," Wessely explained.

A previous prototype, PhotoChromeleon, also utilized special photochromic dyes and UV light to change the colors of various real-world objects, but ChromoUpdate speeds up the process significantly. The older version, which utilized a UV LED, changed the appearance of objects by first resetting all of their colors to black, but the new, UV projector-based system instead works on a pixel-by-pixel basis, meaning that an object can seamlessly shift from one color to another with no intermediary steps. Black-and-white designs, meanwhile, can be printed in under a minute, essentially allowing creators to preview different graphics before deciding to apply color.

In one demonstration of the new technology, the team designed a mug that has the weather, the date and a professor's daily schedule printed on the side. The mug can be updated throughout the day to mark weather changes and to cross out items on the professor's to-do list. The team also experimented with phone cases, transforming an image of a simple treeline on one such case from a starry, midnight-blue night background to a vivid yellow sunrise. Similarly, it morphed a dull black-and-white image of a parrot into a more life-like depiction with bright blues, greens and reds in its feathers.

The system shows promise as a means of reducing waste, as buyers may have less incentive to purchase new products if it's possible to instead redesign them over and over again — buying one high-quality T-shirt, for instance, and trying out different designs, even over the course of a single day. Or, rather than purchasing a set of phone cases with different colors, consumers could instead purchase one case that has been coated in the special paint so that it can easily be programmed into whatever color or design a user prefers on a particular day. Even higher-priced items such as cars could be redesigned to match the whims of their owners, Wessely said. 

The team envisions an open-access platform where users could easily upload their own unique designs and, in turn, download custom designs from other creators that could be applied to whatever household items they'd like. "What this will lead us to is, of course, an open question," Wessely said. "It's up to everyone who is creative to make use of this and find novel applications for this technology."

The paper "ChromoUpdate: Fast design iteration of photochromic color textures using grayscale previews and local color updates," presented May 12 at the Association for Computer Machinery's Special Interest Group on Computer-Human Interaction Conference, was authored by Michael Wessely, Yuhua Jin, Cattalyya Nuengsigkapian, Isabel P.S. Qamar and Stefanie Mueller, Massachusetts Institute of Technology; and Aleksei Kashapov and Dzmitry Tsetserukou, Skolkovo Institute of Science and Technology.