Here is the crochet pressure sensor.
The main principle is same as regular pressure sensor. Instead of conductive fabric or thread, I used conductive yarn from Schoeller, Nm 50/2 60/40 Pes/Inox @ Euros 65.00/kg (25,000 metres/kg). Since this yarn is very thin, it is mixed with normal yarn and crochet, which is what you can see as gray patch in the middle. For the resistive material, anti-static foam is used instead of velostat to support the sensor shape.