Armed with our initial vision of a base garment that could essentially play videos or images on its surface, let’s explore some of the challenges that need to be addressed before this could become reality.
Last time we talked some of the safety considerations of such a garment. This time, let’s discuss some additional safety considerations, namely the circuitry for such a garment.
A ‘video garment’ such as we’re discussing is nothing more than a large play-back device. But in order for it to actually work, it needs to both receive data to actually play back on its surface, and it needs power to perform the playback. So the garment needs to be able to conduct two things in its circuitry: data, which must be uninterrupted, and power, which must be controllable for both on and off states, as well as possible rates of change.
Any circuitry which is used for playback must be uninterrupted, and must not lose connection when the body moves and changes under it. As the garment follows the body contour and movements, the circuitry cannot be disrupted or the entire image will be disrupted, often in strange ways.
What sort of materials might be used to ensure that dataflow remains persistent? There are currently a range of materials which are used to conduct power/data, including fiber optics, thin metal threads (usually copper), and of course, metallic, printable inks.
Each of these materials has advantages and drawbacks: fiber optics are relatively inexpensive, being an ‘older technology’, and can be easily handled just like any other thread and woven into a garment. It is already used to carry optical data and lighting, and lovely textiles have been created using fiber optics. Some drawbacks to fiber optic textiles are that they are itchy for a wearer; if an optical thread is bent, it loses signal; and there is now easy way to connect up optical threads from different pieces of the garment (such a thread would need to be knitted into a one-piece tubular garment, which would change the addressing properties of the garment to playback imagery or video). Fiber optics are largely inert, so a wearer wouldn’t need to be concerned about the material having any dangerous chemicals being off gassed onto their skin. Safety considerations would be relatively minor other than the possibility of the fiber optics bending and breaking and perhaps scratching the wearer. Seams would need to be sealed carefully to prevent wearers from being hurt by the sharp cut ends of the optics.
Thin metal threads have also been used to carry data and power. Very fine threads of copper metal are created, and simply woven into the textile just like any thread. Like the fiber optic thread, it too shares some of the same issues of not being able to readily connect the threads between two pieces of the garment, and while the copper thread would be softer and not prone to shattering, it might still be a scratchy experience for the wearer. Moreover, such a garment would need to be cleaned very carefully, as copper is reactive to many substances, and over time, it can oxidize, which reduces its effectiveness as a conductor. Lastly, it would need to be sealed in some way to prevent any voltage leaks or verdigris stains from the copper oxidizing.
The third sort of circuitry would be the use of metallic inks. This is currently being used effectively in the toy and home furnishings industries, and can be easily printed onto a textile base. Unlike the woven in fiber optics or metallic threads, metallic inks can be printed on a garment after it has been largely constructed. This means that there is a complete circuit, without gaps at the seams which need to be connected. Moreover, the metallic inks can be overprinted by an impermeable, protective layer of polyvinyl chloride or polyurethane, which prevents seals the printed circuitry behind a protective layer that prevents leakage of voltage, data, or harmful chemicals from the ink itself. While this may sound great, there are still safety considerations, as printing metal-based ink often produces toxic fumes which need to be handled carefully. Metallic inks haven’t been in use long enough to know how they respond to laundering, and they have not been extensively used on a range of product classes, so it is unclear how they will wear or respond to cleaning considerations.
It is possible, that with something like a flexible OLED for the base material, that the circuits could be designed to be embedded into the base material, which would remove many of the safety considerations and health hazards that a woven or printed circuit would have.
Next time: powering up the garment.