Step 5: Closing the sensor
Before closing the sensor you will want to cut out a piece of Velostat that is just a little bit smaller than your pieces of neoprene. This piece of Velostat will go in between your two conductive stitches. And this is what creates the pressure sensitive change in resistance. The Velostat lets more electricity through, the harder you press the two conductive layers together, with the Velostat in between. I'm not really sure exactly why this is, but I imagine it's because there are carbon particle in the Velostat that conduct electricity and the more pressure on them the closer they come together and the better they conduct or something similar (???).
So, place the piece of Velostat in between and sew the sensor together as shown in the pictures. Don't sew too tightly, otherwise you'll have an initial pressure which will make your sensor less sensitive.