There are many different kinds of fabric displays. Some use a still image as a starting point, relying on fabric with special properties to make the design more eye-catching. Other fabric displays can show full video with sound. Each method relies on different technologies, and all have their advantages and disadvantages.
A few fabric display techniques are readily available to the consumer market. Creative individuals have used fabric display technology to build elaborate costumes. Jay Maynard used electroluminescent wire (EL wire) in the costume he built based on the Disney film “Tron” — his Web page describes how made the costume. His efforts gained national attention, and before long Maynard was making the talk show circuit as “the Tron guy.”
In this article, we’ll look at the different ways inventors have modified clothing to make a bigger impact on audiences. We’ll learn about an idea for fur displays that use electrostatic charges to shocking effect. We’ll see how a heat-sensitive dye can turn a normal T-shirt into a very large mood ring. After that, we’ll explore the world of electroluminescent clothing. Then we’ll see how LED and PLED displays can turn a normal outfit into an eye-catching light display. Finally, we’ll learn about companies that have created clothing with built-in television and PC displays.
Fur Fabric Displays
There has been some confusion about what, exactly, a fur fabric display is. Philips Electronics filed a patent application with the simple title “Fabric Display,” though some science blogs and magazines have referred to it as “furry television.” At its most basic level, this fur fabric display relies on a very simple technology. Patches of fur cover an image, and when the fur moves, it reveals the image underneath. It’s a simple way to conceal and reveal designs.
The fabric display has three layers. The bottom layer is conductive, which means it can carry electricity from a power source — like a small battery pack — to the rest of the fabric to create an electrostatic field across the fur, which gives each strand of fur the same electrical charge.
The next layer in a fur fabric display is the fabric’s base color or design. This could be a company logo, a picture or just a particular color. The furry display doesn’t change the design on the cloth; it just hides or reveals portions of the design at a given time.
The third layer is the fur. It can be any color, but it must be short enough so that when the user turns on the electrostatic field, the strands stand on end and reveal the design or color of the fabric underneath. For example, in a simple fur fabric display, you could use red fur to cover a blue shirt. When you turn on the power for the conductive layer, the red fur would stand on end, revealing the blue shirt underneath. To a distant observer, it would appear that the shirt had just magically changed colors.
The patent application refers to each small, visible section of the base fabric as a “pixel,” which may be why some articles refer to the display as furry television. While it might be possible to approximate primitive animation techniques by printing one image across the fur layer and a slightly adjusted image on the fabric underneath, it’s not quite the same as watching television on someone’s jacket.
Thermochromic Fabric Displays
The word “thermochromic” looks a little intimidating at first, but the concept itself is pretty simple. Thermo comes from the Greek word “thermos,” which means warm or hot. Chromic comes from “chroma,” meaning color. A thermochromic substance changes color as it changes temperature. In fabrics, a special dye acts as the thermochromic agent.
Some thermochromic dyes change from colorful to clear, revealing the color of the fabric underneath. Companies can use thermochromic dyes in shirts that slowly reveal a company slogan or logo as the shirt heats up. When the shirt cools down, the logo seems to disappear.
There are two widely used elements in thermochromic dyes, and both rely on chemical reactions:
- Liquid crystals: These thermochromic dyes rely on liquid crystals contained in tiny capsules. The liquid crystals are cholestric, also known as chiral nematics, which means that its molecules arrange themselves in a very specific helical structure. These structures reflect certain wavelengths of light. As the liquid crystals heat up, the orientation of the helices changes, which causes the helices to reflect a different wavelength of light. To our eyes, the result is a change in color. As the crystals cool down, they reorient themselves into their initial arrangements and the original color returns.
- Micro-encapsulate thermochromic system: In this system, the thermochromic dye contains millions of tiny capsules that look a little like an organic cell. Each capsule has an outer membrane and contains an organic, hydrophobic solvent, which makes it less likely that water will dilute or wash out the chemicals in the dye. The solvent contains particles of a color developer and a dye precursor. As the capsule heats up, the solvent melts and a chemical reaction causes the color developer to donate a proton to the dye precursor. In turn, this causes the precursor to develop into the dye itself and change color. When the dye cools down, the developer and precursor separate, the solvent resolidifies and the color returns to its original state.
Like fur fabric displays, thermochromic fabrics aren’t animated — they can only conceal and reveal designs or colors based on environmental conditions. While that might be enough for some people, others want even more dynamic clothing.
For more Detail: How Fabric Displays Work