In the last few posts we looked at how nature can offer great inspirations to creative minds. While yesterday we explored the creative possibilities offered by shape-shifting creatures, let's move on today and examine the colour-changing capabilities of chameleons.
We can all try and camouflage ourselves with the environment surrounding us by changing the colours of our clothes, but inanimate objects can't really change colour. Or can they, wondered a team of researchers at MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL).
Moving from this question, the CSAIL team developed a reprogrammable ink that allows objects to change colours when exposed to ultraviolet (UV) and visible light sources.
The system is called "PhotoChromeleon" and consists in a mix of photochromic dyes. Once sprayed or painted onto the surface of any object they will allow users to change its colour (a reversible process that can be repeated infinitely).
PhotoChromeleon is a development of "ColorMod" that employed a 3D printer to fabricate items that could change their colour, a project that only allowed users to employ a limited colour scheme as the printer had to 3D print individual voxels for each color (with ColorMod an object could, for example, only go from blue to transparent when activated, while PhotoChromeleon's ink allows to create animal prinst like a zebra or a checkerboard pattern with varying checkerboard widths or a multi-coloured effect) and the quality was rather low.
The ink used in the PhotoChromeleon project was created by mixing cyan, magenta, and yellow (CMY) photochromic dyes into a single sprayable multi-colour solution. Once obtained, the solution was sprayed onto an object that was then put in a box with a projector and UV light.
The UV light source saturates the colours from transparent to full saturation, and the projector desaturates the colors as needed. When the light activates the colours, the new virtual texture programmed by the user is transferred from the digital model onto the object (the process can take up to 40 minutes, depending on the surface of the object you want to cover with the pattern).
By understanding how each dye reacts to light and interacts with different wavelengths, the team was able to control each colour channel through activating and deactivating the corresponding light sources. Different lights with different wavelengths eliminate each primary colour separately, so a blue light is absorbed by the yellow dye and deactivated, while magenta and cyan remain, resulting in blue. Green deactivates instead magenta, and then both yellow and cyan would remain, resulting in green.
If you aren't happy with the design you have created, you can use the UV light to erase it and you can start over again, but the inks are bi-stable so, once you're satisfied with your pattern, they will remain on the object even when the light source is removed. The process is fully reversible and users can recolour the object as many times as they want.
The team experimented the ink on phone cases, a toy car and a pair of shoes, but researchers hope in future to be able to apply a similar system to a wide range of products and plan to collaborate with material scientists to develop improved photochromic dyes and possibly extend the fabrication methods to 3D printing with filaments and resins.
The automotive industry is currently very interested in this project as re-programmable colour-changing coating could enable buyers to explore different textures or patterns on a product in a showroom, while re-programmable coating could also be used in car-sharing or to display changing advertisements on the car exterior.
Ford worked on the ColorMod 3-D technology with MIT and also followed the developments of this new research, but it would be amazing to see MIT collaborating with a fashion designer such as Anrealage's Kunihiko Morinaga, who has already created collections characterised by photochromatic prints.
Photochromic shoes, textiles and accessories mean that we could alter the appearance of our outfits as many times we wanted to without having to buy new ones.
"This special type of dye could enable a whole myriad of customization options that could improve manufacturing efficiency and reduce overall waste," Yuhua Jin, the lead author of a new paper about the project states on the MIT site. "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."
There could also be applications in interior design with rooms in which walls or furniture could be re-coloured thanks to a ceiling mounted UV/projector system or in dynamic physical visualizations (think about weather forecasts projected on a 3D printed earth sphere).
So maybe the future of many industries, fashion included, stands in programmable matters that can change itheir physical properties in accordance with our needs. The PhotoChromeleon project will be presented at the User Interface Software and Technology Symposium, in New Orleans, from 20 to 23rd October, in the meantime you can read a paper about the project here.
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