Have you ever longed for a magic dress that changes itself while you are wearing it? Well, someone has, because it is a trending topic in Ambient Intelligence.
Actually, color change is already solved (up to a point) and the answer is a substance known as thermochrome, that changes colors depending on the temperature. There are two blends of thermochromes: liquid crystals and leuco dyes. The first ones, you have probably seen in (cheap) thingies like mood rings or color changing mugs. Leuco dyes are a combination of colored chemicals that react when temperature goes over 25º C (approximately) and become colorless. The reaction is reversible, so when the temperature drops, they gain their color back. A layer of leuco dyes can be applied to any cloth and the resulting color is the combination of its original color and the substance … until it goes colorless. (Not so) Instant color change!
Of course, heat is kind of ok for a mug, because you can check whether the liquid inside is cold or hot, but not so much for clothes, because temperature tends to change too slow for changes to be too flashy. Other substances can be affected by different stimuli, like light, heat and friction. Lauren Bowker, from the Unseen, worked out a new ink (PHNX) that reacts to seven different parameters in the environment, including air pollution, heat, air friction and moisture. This basically means that your sweater could switch colors when you move from one part of the city to another. Chameleon style!
Cool, right? Well, you don’t have to pretend. I know that when we started talking about color changing fashion, you were thinking of this:
Well, maybe we can’t get exactly this (pity), but, is it actually possible to change textiles at will if we mix thermochromes and electronics. Take, for example, Chromosonic, by Hungarian designer Judit Eszter Karpati. She also relies on a temperature-sensitive dye, but instead of leaving changes to the whims of nature, she has actually woven nichrome wires into the fabric.
Nichrome is a fairly well known alloy of nickel, chromium and other elements that has been widely used as industrial heater. If one heats up the wires in a pattern using, for example, a microcontroller, the dye in the surrounding textile changes colors responding to the pattern, which, in the case of Chromosomic, turns out to be an audio file. Problem is, obviously, that it’s actually way easier to heat things up that to cool them off.
… or, if you want to stick solely to electronics and make a dress that it’s not just a christmas tree, you can actually sew sensors and LEDs into your fabric and make it sensitive to whatever magnitude you want to measure. Environment Dress, from UH513, won the Next Things 2015 award doing exactly that. Only for the brave people, though!