CircuitPrinter
What’s going on here: This is an Epson L310 inkjet printer, loaded with conductive ink to allow it to print circuits onto paper. The printer itself isn’t really anything special, aside from the fact that it uses tanks to hold ink instead of cartridges, which makes it much easier to add nonstandard inks.
Ink: The ink is a suspension of silver nanoparticles, making it able to conduct electricity just dandy. It is not cheap, and we currently don’t have a whole lot of it. So please refrain from printing out your massive epic circuit diagram that you’ve been adding to each year as a metaphor for your life, and I would also prefer it if you refrained from using this printer just because you want your artwork to be shiny. I’m working on the supply issue, and yes I want people to use the printer, just don’t be a dick is all. Thank you.
Paper: The circuits can’t be printed onto any old paper. According to the ink manufacturer, the paper they sell is specially designed to something something better conductivity, although they acknowledge that glossy photo paper will also work. Update: Photo paper is totes functional.* So that’s what we’re going with. Paper goes into the printer glossy side up. The manufacturer supplied paper that’s size A6, which is about ¼ the size of a normal sheet, probably because circuits don’t need to be that big. Seems like a good idea, and I’d like to figure out how to reliably cut to that size as a standard. Until then, just try not to waste too much paper. Or ink. I may have said that already.
- After shopping around a bit, I've learned that not all photo papers are created equal.
Brands that do work: HP Advanced Photo Paper.
Brands that do not work: HP Everyday Photo Paper, Bonsai Glossy Photo Paper - Waterproof Resin Coated.
Design: If you have your circuit as a pdf of image, that’s awesome, just plug your computer into the USB cord coming out of the printer and go to it. Make sure you have the right size paper selected, and also glossy and high quality, hit print, and you’re done. If your design is in Eagle, you can print directly from there, but I haven’t found a way to change print settings, so it’s a lower quality print that comes out. No idea yet how much of a difference it makes in terms of conductivity or anything, so to be safe, I recommend exporting your design as a high quality image, and then printing the image.
Other: We also have a pen that can draw with the same ink, a tube of paint that behaves similarly, and a few rolls of thin copper tape, all of which can be used to draw out circuits. Looking online I've also found conductive thread, fabric, Velcro, and a recipe for conductive playdough. This page may turn into Alt-Electronics or something depending on how many toys are brought in.
More info
Silver Ink: https://agic.cc/en/
Printing an Arduino: http://www.instructables.com/id/Paperduino-20-with-Circuit-Scribe/
Circuitry with LED stickers and copper tape: https://chibitronics.com/education/
LED origami balloon: http://www.evilmadscientist.com/2008/paper-circuitry-at-home-electric-origami/
The bottom right corner of the paper has a battery in the binder clip. The fold is touching the + and - sides of the battery, sending power to the LED, which is fastened with masking tape.