This neat Chibitronics birthday card was created by member Zeve at the Instructables Chibitronics Build Night at CRASHspace during the monthly Circuits Social event. Chibitronics is a kit system for building electronic circuits on paper. Circuit elements are essentially stickers with conductive adhesive, and include LEDs, buttons, sensors, effects, and even a microcontroller.
Step 1: Tinkering
We had a nice showing at the event, and plenty of tinkering going on. Chibitronics has a slew of tutorials and videos, as well as a Circuit Sticker Sketchbook, which is a collection of their tutorial templates. It's available in print version, or pdf. For our event, we printed several templates from the sketchbook pdf so that people could get an idea of how they worked before venturing off on their own ideas.
Zeve used the simple circuit template to get a handle on the materials, then he decided to make a paper logic gate, because Crashspace is chock full of geeks. :) Check the pictures to see it!
After this, and since his mother's birthday was coming up, he decided to try his hand at a circuit sticker birthday card.
Step 2: Materials
- Paper (Zeve used white cardstock to make his card, though plain printer paper works. Vellum is also nice due to its translucence)
- Chibitronics Circuit Sticker LEDs
- Copper Tape (some copper tape has adhesive backing, some does not. For this project, he used conductive backed tape, which makes patching breaks in the circuit easier)
- Binder Clip
- Coin Cell Battery (2032 here, others work as well)
- Person with an upcoming birthday (optional, but that's kinda the point, isn't it?)
- Multimeter for debugging (someone located our missing favorite multimeter, and many people used it during the build night)
- Craft knife, Cutting board, and Pencil (if you want to do the papercut part)
Step 3: Wiring the Letters
Zeve says that the trickiest part of the whole enterprise was laying out the copper tape to spell letters. I believe him. Placing down the tape is easy and darn addictive, and there's an extremely helpful video showing how to bend the tape at 90 degree angles (short version: first, bend opposite the direction you actually want the tape to go in, then bend back). It also gives tips for the curved shapes that are necessary for an annoyingly large number of English letters.
He didn't draw the pattern on the paper to begin with (though I sure had to when I wanted to recreate it), but it's not a bad idea to sketch out the letters first.
Step 4: Light It Up
The triangular-shaped LEDs were placed in targets of opportunity. To avoid shorting the LEDs, some strategy was required in "typesetting" letters such that there was room for one conductive pad of the LED in one region of a letter, and the other pad in another region easily connectable to the other voltage level. With the LEDs placed, additional traces were laid down to connect them, above, beneath, and through other letters to the battery. As Zeve managed to paint himself into a corner, some traces had to be run over and around the back, resulting in a two-layer birthday card. In a future revision, it should be possible to do through-hole vias using a hole punch and metallic brads or buttons, greatly reducing routing congestion.
I wound up running some copper tape behind the card as well, but I have to say - his electrical maze has character. :)
Step 5: Debugging the Card
Ever think you'd be debugging a birthday card? Yeah, me neither. Yay for unexpected experiences!
When first laid down, most of the LEDs didn't light, most likely due to micro breaks in the copper tape due to all the folding. A multimeter used in conductivity test mode was essential for finding such breaks, which could then be fixed by patching over the affected area with more conductive tape. This allows current to flow up through the conductive adhesive and over and around the problem area. Even when patched, intermittent conductivity in the traces caused a really lovely and fortuitous LED flickering effect.
Another unexpected debug moment was when a highly educated engineer misspelled "birthday." See pictures. Fortunately, he has a good sense of humor.
Step 6: Papercutting
Zeve came up with and created his fabulous card all on the night of the event. I decided to recreate it later and give it a bit more decor in the shape of a papercut cover.
The flowers in my design each coincide with an LED. I accomplished locating them on the folded over paper by pressing down and using the indentations to guide my sketch (see picture). I knew where the flowers would be, so I did a little doodling to connect them, and then cut it all out. You'll notice the strategic strips of paper across the cut pattern that make the cut surface a bit more united.
You can also see where I inadvertently cut all the way through some of the copper tape traces. D'oh! Sidestep with more copper tape.
Finally I erased the extra little pencil lines remaining on the card.
Step 7: Finished Card!
Zeve was excited to get it all completed and working, his mother reportedly liked her card, and we had a grand old time at the build night.
Hope you enjoyed. Make a circuit birthday card of your own and share with us!