Ever wanted to stab the living day lights out of someone? This little voodoo doll was created to do just that! If you hit the right areas, gratifying LED's light up. This is a super simple circuit for electronic textiles, and it is possible to make without any special materials. I am making this tutorial to be used in conjunction with the Craft Technologies course taught at Utah State University, and their Computational Craft Lab to introduce simple electronics to students who would normally not play with them.
Step 1: Supply List
Old Instructables Author T-shirt
Steel Pin for Sewing
6 Light Emitting Diodes, Different Colors
Coin Cell Battery (CR2032)
Coin Cell Holder*
Thin wire, such as telephone wire can be used in place of conductive thread
Heavy Aluminium that has had double-sided interface ironed to it can be used in place of conductive fabric
Finally, a fabric battery holder can be made instead of using a plastic battery holder
See end of guide for more about alternatives.
Disclaimer: All links are provided for ease-of-use of this instructable, and I have no affiliation with any of these business. Just because I added the link to one store does not mean that the item is only available there. I have had luck finding conductive thread at Hobby Lobby, although it costs an arm and a couple of toes.
Step 2: Prepare the Body for Operating
Take an old Instructable author t-shirt and cut out the robot print from both layers of fabric, leaving about 1/2" on all edges to counteract how the body curves when stuffed.
Step 3: Aziz Light!
Time to decide where to put the LED's! I chose the rather obvious placement one would chose for the Instructables robot, consisting of eyes, chest diodes, and head side wires. It is not necessary to stick the LED leads through the fabric, I did this because they kept moving from where I wanted them to be.
Step 4: Diagram Map
It is incredibly important to know where one is going, on a road trip, as well as with E-textiles. Circuitry needs to be thought out and preferably drawn out. Drawing it helps to avoid having to sew each one of these iterations and having to pull it all out again when I sew myself into a corner with conductive thread. This drawing will be used as a map for me to follow, therefore I desire it to be as clear and specific as possible. It took me 5 iterations to get the best map.
The circuitry on this is pretty interesting. In an effort to simplify the wiring diagram and not need 3 ports on a micro-controller to connect the LED's to, I had an epiphany. All of the LED's are connected to the same positive trace. They are all receiving power at the same time, all though none will light because the circuit is not completed by connecting to the ground (-) side of the battery. Each set of LED's ground leads is connected to a conductive patch on the inside front of the body. By having a steel pin stabbed through the patch, it connects that set of LED's to ground, completing the circuit, and lighting those LED's. This makes wiring much easier, even if it is a little more conceptually confusing. Don't believe that it will work? Try a mock-up with alligator clip test leads, LED's, and a battery.
Step 5: Patch Him Up, Doc
Now that I have my map, I know where to add the conductive fabric patches and what shape to cut them in. Using knit conductive fabric, I ironed on fusible adhesive, and then cut out the shapes that I needed.
Step 6: How to Ruin Your Iron
Remember that this silver conductive material is actually nylon, and will melt if you try to iron it without any protection. After I silver-plated my iron, and then painstakingly cleaned it off, I used a scrap of paper as a heat buffer between the iron and the silver patch. It was necessary to hold the iron in place longer to let the heat sink through the paper, but at least nothing else melted.
Step 7: LED Surgery
I selected 3 color sets of 2 LEDs each, Red, Blue, and Multicolor. By using a pair of round nose plyers, I curled the leads of the LED's to make them easier to sew. The problem with this is that it makes it difficult to remember which side is positive and which side is negative, so I made all of the positives zigzag, and all of the ground (-) leads circular.
Step 8: A Little Bit of Security
To Secure the LED's and the battery holder to my robot doll while I sewed them on with conductive thread, I decided to loosely sew them on with non-conductive thread first. You can use tape to secure them, but it tends to come off or lose bits. If you look closely at the picture, you can see where I used the black thread to secure the components. As this project was done in my spare time over a couple of weeks, it was important to me not to lose any bits from tape falling off.
Step 9: Sew a Little Here, Sew a Little There
These are front and back photos of the traces and components being sewn on with the conductive thread. It is helpful to cover knots with a tiny bit of clear nail polish or Fray Check, so that it doesn't untie itself, undoing all the hard work that it took to get to this point.
Step 10: I'm All Lit Up Again...
Check to make sure that all of your sewing and lights work the way that they are supposed to *before* sewing and stuffing the doll shut! Also very fun to see the lights coming on for the first time with my handiwork. I used an alligator clip test lead by attaching it to where the future conductive pin will be attached to(ground (-) side of the battery holder), and touching the conductive thread traces that leads to that conductive patch.
This is where you would use a multi-meter if you have found issues, such as more lights lighting than they are supposed, or no lights lighting at all. Also, make sure that the battery is not drained if you have no lights at all.
Step 11: Around and Around We Go
With non-conductive thread, sew the body mostly closed and turn it inside out, being careful to avoid ripping off any of the components.
Step 12: Stuff It Like a Build-A-Bear
Stuff full with polyester fiberfill (an old pillow will do), and then sew closed.
Step 13: Add Stabby Bit
For the stabby ground(-) trace, check that what ever is used for a pin is conductive. The easiest way to do that is to use the multimeter. I made this one with a remainder of sticky woven conductive ribbon, which I folded in half with the head of a steel pin inside, and then wrapped with a small piece of conductive wire to secure it. Be creative.
Step 14: Somebody Needs to Be Grounded
Time to sew the stabby ground (-) component to the ground (-) side of the battery holder with conductive thread.
Step 15: TaaDaa
All Dones! Same video as the one at the beginning of this Instructable, to save time for those just passing through.
Step 16: Alternative Materials
Thin wire, such as a single strand of telephone wire can be used in place of conductive thread. By stripping and curling the ends, the wire can be sewn onto a piece of fabric, having the curled end making direct contact with the patch, LED lead, or battery holder end.
Heavy Aluminium that has had double-sided fusible adhesive ironed on to it can be used in place of conductive fabric. It is not the best idea for something that will be used a lot as an example, as the pin will eventually break it into small pieces.
A fabric battery holder can be made instead of using a plastic battery holder by creating a pocket where the thread for positive is on one side, and the thread for ground (-) is on the other side. Just make sure that you are not causing any shorts while the stabby doll is being powered. A good example is this needle felted battery holder instructable made by moxie. If you don't have felting needles, something very similar can be made with normal cheap felt and sewing techniques.