Jeri Makes Flexible EL Displays

A failed chemistry experiment led [Jeri Ellsworth] to discover a flexible substrate for electroluminescent displays. We’re familiar with EL displays on the back of a glass panel like you would find in an audio receiver, but after making a mesh from aluminum foil [Jeri] looked at using the porous metal to host phosphors. She starts by cleaning foil and using a vinyl sticker to resist etching portions of the aluminum. It then goes into a bath of boric acid, electrified with the foil as the anode. As the foil etches she tests the progress by shining a laser through the foil. After this the phosphors are applied to the back surface of the foil, covered in a dielectric, and topped off with a conductive ink that will carry the AC necessary to excite the phosphors. This is layering materials in reverse compared to her EL PCB experiments. See [Jeri] explain this herself in the clip after the break.

You can see above that this produces a pretty well-defined display area. It reminds us of that color changing paint display. We think it would be worth a try to build a few 7-segment displays using this method.

[via Instructables]

19 thoughts on “Jeri Makes Flexible EL Displays

  1. @Caleb

    Sounds like someone has a bit of penis envy…

    seriously she does really great work, and I wish that someone else out there could think on such a large scale as she does. Fact is though, atm nobody is willing to step up for the task. Most of us, I’m sure, would have threw away the foil from this experiment and thought nothing of it.

  2. You will get more consistent anodizing if you don’t allow metals like Iron, Copper to touch the Boric acid solution while anodizing. That includes your alligator clips! Metals like Lead and Titanium are used commercially as the cathode material to anodize aluminum. You can also use Sulfuric Acid as the electrolyte (1:1 battery acid:water). The advantage of Boric acid is that it makes a denser (tougher) anodized film. Current density also greater effects the quality of anodizing. The higher the current density, the softer the resulting film.

  3. Hmm I wonder how well this could be applied to vehicle skin. It would probably look like crap unless you flood the entire thing in clear coat but I think it could work. Instead of solid foil the transfer foil could possibly used…gold? Then stencil on the pattern and clear coat it at the end….hmmmmm

  4. Neat hack jeri :-) i was wondering how to make a front contact which could take a reasonable amount of current.

    makes sense to use Al foil as it is easy to get hold of.

    Wonder if the same technique would work with any other materials such as Cu PCB stock?

  5. make small holes with a thin needle? ;)
    or if you develop a battery to a wire anschlisst and this underlines the aluminum foil over these holes;), sorry for my english i use a translator :/

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