This project is relatively inexpensive when compared to buying replacement sensors from Zeo (although now that they are out of business, this is moot). For a little over $35, you can buy enough material to make DOZENS
of replacement Zeo sensors.
The most unusual material in this project is the conductive fabric for the pads that contact your forehead. I bought the MedTex 180 fabric from SparkFun and it looks and feels exactly like the material used for my original Zeo pads. The 12" x 13" sheet will set you back twenty bucks, but there is enough material to make about 30 sensor pads. For comparison, I also purchased the cheaper RipStop fabric from SparkFun ($9), but it seemed too stiff to work well. It might work, but I recommend spending the extra money for the MedTex 180.
The second critical component is the fabric snaps. They have to be the right size and style to snap into the back of the Zeo. I used Sew-Ology No 16 Pearl Snap Fasteners, 7/16 in and they worked perfectly. These are sold as packages containing matching studs and sockets, but only the studs will be used in this project. Each sensor pad will require three fasteners. Hint: It is important that the studs and prongs be metallic and unpainted, as they need to conduct electrical signals. The first set of snaps I bought had bare metal studs but painted prongs. These can be made to work, but require more effort (I'll explain this later).
The rest of the materials in this project can be found at your local hobby and crafts store.
You will definitely need scissors and a hammer. If you use iron on patches as I suggest here, you will need a regular clothes iron. The iron on patches gives your project a nice finish, but are not required. You could also get away with just using plain fabric and sewing or using staples to hold it all together.
Having a 1/8 inch hole punch is helpful, but not required. Such hole punches can be found at your crafts store, but it might be tricky finding that exact size. You don't really need it, but it might help if you can find it. Materials:
- MedTex 180 Fabric ($19.95 for a 12" x 13" fabric sheet from SparkFun
- Heavy fabric (I used black twill, $1.75 for a large piece)
- No 16 Snap Fasteners, 7/16 in ($4.29 from HobbyLobby
- Iron-on fabric patches (I got a set of several at the supermarket for under $2.00)
- Yarn or string (I paid $5.99 at HobbyLobby for more yarn than I can use in a lifetime!)
- Heat shrink tube or plastic stir straw
- Double sided foam tape Tools:
- Clothes iron
- Stapler (regular size and TOT50 mini-staples are helpful)
- 1/8 in hole punch, such as this
(optional, but very helpful)
- Needle and needle threader (optional, but helpful)