Add-Ons Go Electroluminescent

It’s that time of the year again, and once more we’re faced with the latest innovations in Badgelife, the movement to explore the artistic merits of electronics and manufacturing. This is an electroluminescent printed circuit board, and it’s some of the finest work we’ve seen. It’s also a Shitty Add-On that glows blue.

The process for applying an electroluminescent coating to printed circuit boards is, surprisingly, something we’ve covered before. Late last year, [Ben Krasnow] delved deep into a DIY EL display. The process is expensive, but all the products come from a company called Lumilor. The first step in this process is applying a thin conductive coating on a substrate with an airbrush. Since the entire idea of printed circuit boards is to have a layer of conductive material etched into any shape you want, the simple circuit board is the idea experimental platform for playing with EL displays. Traditionally, EL displays were made entirely with a silk screen process, like [Fran]’s ongoing attempt to recreate the Apollo DSKY display.

The electronics for this badge are simply a Microchip MIC4832 EL Driver, which converts the 3.something volts from the add-on header into 100 or so Volts AC at hundreds of Hz. This is a single-chip solution to driving EL displays, and the only other parts you need are an inductor, diode, and a few caps and resistors. An ATtiny85 can be used to blink the circuits, or, alternatively, you could copy [Ben]’s work and build a character EL display.

The process of applying an electroluminescent coating to a PCB does require a spray gun or airbrush, and the chemicals are a bit expensive. This, though, is pushing the boundaries of what can be done with artistic PCBs. It’s new applications of technology, simply as wearable electronics. It’s the best example of the possibilities of the medium and some of the best work that’s come out of the Badgelife scene.

24 thoughts on “Add-Ons Go Electroluminescent

    1. Indeed. This is not the first from this author. I wanted to show a friend of mine a cool website today to show him how WordPress is used by mainstream websites, and I refrained from showing him HaD because of what is on the first page. I’m not going to compromise my professionalism.

    2. +1 unprofessional, unnecessary, unpleasant, and means I have to be careful not to access HAD at work becsuse I strive to be professional nor at home because I strive to be a good father.

    3. It always amazing me how people define “bad language”. Here we have a title with what is considered a “curse word”. The word is actually part of the name of a project and not directed at anyone. However, the same person who determines that this is bad also turns around and thinks its OK to call someone a moron. I don’t understand the logic.

      1. Agree. Where i live a place close to me called Scunthorpe used to be filtered out of search engines many moons ago. Easy to work out the crude word. As for Newark : an anagram for wanker made us chuckle as kids.

  1. Looks like I missed some drama with the title?!?! Oh I just got what the issue was. Really? Are people so inflexible that they easily get offended by a single word (which really is low on the totem of expletives to begin with)? And complaining about professionalism when this is a hacking site (basically the antithesis of rigid professionalism), like we already don’t know how 99% of companies feel about the connotations of the term “hack” irrespective on the actual content. How thin skinned can some people get that this is the wrench that jams the gears?

    1. It’s surprisingly fairly basic:

      * A conductive base layer (typically copper)
      * A dielectric layer (I believe typically titanium dioxide, but any dielectric that forms a decent capacitor works)
      * Some kind of Zinc based compound doped to emit a specific color (ZnO + Mg for red-orange, ZnS+Cu,Al for green, and ZnS+Ag,Al for blue)
      * A transparent conductive outer layer, with the two common ones being ITO coated glass (where the EL panel is built front-to-back onto the glass) or PEDOT:PSS (where the EL panel is built back-to-front onto whatever the copper is laid down on, like a PCB).

      Usually each is suspended in some kind of material that lets you apply these solid powders using liquid processes and adhere to the layer below them, but other than the copper (which isn’t needed if you’re building on a PCB) or the PEDOT:PSS (which I think just needs water but don’t quote me on that) some basic alcohol or maybe acrylic base might do fine if you can get it.

      The main reason the actual Zinc EL materials end up so expensive is a combination of purity and some treatment to keep them safe from moisture that tends to wreck the crystal structure and therefore degrade the EL capability. That and branding markup.

      1. why cant the el panels be made in a large vacuum chamber flushed with nitrogen gas to keep the moisture out?

        i know nitrogen is used in refrigeration lines to purge moisture before being vacuumed out and charged with refrigerant.

        looking up the substances on wikipedia i found no legal or restriction issues that would require license to buy or handle in large amounts so the only thing i could think of is that el can provide a better lux to watt ratio than any other form of lighting even to the point where it is a threat to the power co’s profits as it draws so little power that it wont even register on the power meter.

        yes with a big enough panel it could replace a light bulb

        as of branding markup the chinese could make no name el panels and dump on the market.

        another possibility is to get a big enough panel to light a house would require an inverter to oscillate at a frequency high enough to cause radio interference and knock out every emergency responder’s radios within a multi mile radius just like the neon sign inverter did in an older hack a day post .

        1. A nitrogen chamber is fine and all for making the panel, but the vast majority of panels are not made to be air tight because it’s not a requirement for their function and adds cost when all you need to do is dump some hydrophobic coating onto the phosphorescent powder’s grains to extend the lifetime enough to be useful. Additionally the spray-on EL paint featured in the article here was actually meant to be applied on cars, which regularly get exposed to the elements.

          There are plenty of places you can actually get the basic phosphorescent powder for cheap on the typical chinese bulk sites (just be sure you get the ones that actually work for EL, as apparently there are other phosphors that I guess don’t work as well, if at all?), but it’s just the powder (and probably a relatively impure version of it) so you still have to figure out a way to apply it to whatever you’re working on.

      1. This pertains to the post by sjm4306 above! Don’t know how that happened.

        As to ejonesss comments, I have been following [Fran Blanche]’s project with the DSKY display panel. From what I remember, the chemicals are expensive, and the process requires a lot of care. However if you Google “Electroluminescent Panel” you get a huge range of products, from Adafruit’s flexible sheets (currently out of stock) to various sizes and colours of flat panel. The thing that I couldn’t find out is whether they have enough output to be used for room illumination.

        The physics suggests that they would not be more efficient than LEDs, just by reason of the process by which the light is emitted.

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