Screen Printing Electroluminescent T-Shirts From Tron

Travel around to enough security conferences, faires, and festivals, and you’ll see some crazy wearable electronics. Most of them blink, and most of them use LEDs. Electroluminescent panels are used for wearables, but that’s a niche – the panels are a little expensive, and you have to deal with high frequency AC instead of the much simpler, ‘plug in a LiPo here’ circuit LED-based wearables have to contend with.

Still, electroluminescent panels are cool, and thanks to how EL panels are made, you can screen print EL displays. That’s what some of the guys at AMBRO Manufacturing did recently: screen printing electroluminescent lights directly onto garments. It’s t-shirts from Tron made real.

EL panels and EL wire are really only three separate parts: a conductor of some sort, a phosphor, and another conductor. Pass a high-frequency AC current through the conductors, and the phosphor lights up. With EL wire, it’s a thick copper wire clad in phosphor and wrapped in a very fine copper wire. EL displays are made with conductive ITO-coated glass or plastic. It’s a relatively simple construction, and one that is perfectly suited for screen printing. In fact, one of the first EL displays – the DSKY, the user interface for the Apollo Guidance Computer – used screen printed seven-segment EL displays.

The folks at AMBRO only have a proof of concept right now, but it is a completely screen printed electroluminescent design on fabric. To light it up, the t-shirt will need an inverter, but this is the beginnings of t-shirts from Tron.

Video below.

14 thoughts on “Screen Printing Electroluminescent T-Shirts From Tron

  1. Just one question, can the colour of the screen printed ELD be changed, in the video the white shows up against the black of the shirt, if the ELD was coloured black it could go nearly unnoticed until it was turned on, it would be a much better effect.

    1. I dont have any experience with EL stuff but from what Ive seen you should be able to, could mix in dyes or pigments to the phosphor element probably? Might change the active colour as well slightly, might even be able to just put the display on the inside of the shirt so it only shines through the fabric when active.

      1. Josh, we like the concept of the inside of the shirt display a lot. Having considered this and tested it a little, we’ve run into two problems that we’re trying to work with. Most reasonably durable t-shirts are 5.4 ounces or up in fabric weight. Which unfortunately block a lot of illumination when lit from behind. Some of the fashion tees that are 3.8 ounces or the “burn out” style tees work well for this, but, you end up seeing a lot of print through it as well. Meaning the ink bleeds through the fabric to the surface. If anyone has ideas on these problems, please post because we’re very interested in what the community thinks about possible improvements.

    2. Great question and something that we are experimenting with right now. You can definitely change the color of the print with pigments, but we have to be careful of that because the more pigment you add to the print, the less brilliant the display and, pigments effect the color as well. We’re working on a project right now that will test changing the pigment of the unlit display. We’ll keep Hackaday updated on the experiments.

    1. I sent her the link when I got it. This might make her work a *little* bit easier.

      According to what I rememeber from the last time talking to her, the biggest cost isn’t a gigantic block of aluminum, or a gigantic block of steel to cut a mold for the die-cast case. It’s the price of the phosphor and such. This could be cool. Wrong color, but it is cool.

  2. Sorry guys but the main application method for electroluminescence has been screen printing since around the 80s!

    The reason it hasn’t been used more is that it’s not actually very bright, notice that they have to turn off all the lights so you can see it?

    To answer Hirudinea’s question – you can change the “off” colour by adding dyes or pigments, but it will impact on the “On” colour. Making the display black when “Off” will reduce the overall brightness further as black will absorb in the visible range. The statement in the article that you need just three separate parts isn’t quite right. EL displays also have a dielectric layer next to the phosphor. This is there to hold charge in the device (which is basically a capacitor) and limit current. This layer is usually white so as to reflect more light out.

    And by printing on the inside of the shirt, it will not be bright enough to show through the material!

    1. Mike, I hear you. Yes, the brightness has been a factor, and is something that we’re working on. The methodology is not new, but the components required to make it wearable and durable through wash cycles and bending is. So there are a few things that we need to work through before this is going to be ready to the satisfaction of most makers. First, I agree with you, brightness is a factor and needs to be addressed. Second, this has to bend and be able to sit in water for a while without failure.

  3. “Even thought wearable LED’s, known as Neopixels, are readily available and offer a great option to add light to your garments.”

    Well, that’s a novel re-use of the term ‘Neopixel’. Limor & friends seem to have invented the new ‘Coke’.

  4. I was the electrical engineer on the light suits for Tron Legacy… the material that we used was made by a company in Arizona called ORYON. It was also screen printed, and the process took 11 screens for each EL lamp, IIRC. The lamps were very supple, flexible and cloth-like, and crazy expensive. They draped nicely like fabric, but even small amounts of stretching would break them permanently. They were also fairly bright, with white, orange and “EL blue” being the brightest colors. I drove them with 290VAC @ 1100 Hz provided by custom inverters we made using transformers we had to wind ourselves. The inverters were powered by seven 18650 LiIon batteries and would run the “grid combat suit” (as worn by Sam Flynn) for about 11 minutes. The inverter had to be really small, so it would overheat after about four minutes and would have to be shut down. No room for heat sinks and fans were out due to noise. Each suit had a telemetry & control system controlled by a Synapse RF100 mesh network module; since it was a mesh network, the more suits we had on screen at one time the more reliable the network became. The RF100 was used to turn the suits on when action was called and off as soon as the director cut. The module also reported to me the suit’s cumulative run time (reset at each battery change) and the temperature of the inverter. Quite the learning experience…

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