I recently spent a lot of time researching squib designs for a short film that I am working on. I found that most designs were unreliable, unworkable or expensive. I did find several designs that mine ended up being a variation of which use model rocket igniters. But for my purposes, which involve a lot of squibs, this would be too expensive. I decided to find out how to make my own igniters and came across this great site to which I owe a great debt of gratitude to. Using their recipe for igniter goop and the inside of an old hairdryer, I was able to make igniters tat cost almost nothing.
Please note that I am not a professional anything, let alone a pyrotechnican and I take no responsibility for anything that happens from you trying to do what I have done. This is a very dangerous project if not done properly and all possible safety precautions should be taken when attempting it.
That being said...
Step 1: Materials and tools
For electronically ignited firecracker
1. Nichrome wire (from hairdryer)
2. Black powder
4. Ping pong balls
5. Black cat or similar firecracker
For blood pack:
1. Fake blood
2. Condom (unlubricated for god's sake!)
4. Duct tape
For Battery pack:
1. 3 9v battery clips (sorry, I only had two for the pic)
2. alligator clips
3. Insulated wire
You will also need, along with general tools, a rock tumbler and a bunch of lead balls about 1 inch in diameter to grind down the black powder. These are probably the biggest expense. I happened to have them around so it worked out for me. You could use a mortar and pestle but I personally would not feel safe doing that. It only takes one spark to set off black powder.
If you can find another, safe alternative, please post.