For the Unraveled performance, I have been working with conductive yarn. What I have found is to make sensors with a resistance that is measurable. I don’t focus on the electronics and measurements so much – just what seems to work. A lot of this is based on Kobakant’s How To Get What You Want. So I highly recommend checking them out, especially if you want conductive and resistant measurements.
Basically I crochet a sample of yarn with the conductive yarn and normal yarn just paired together as if I were crocheting with one piece. The conductive yarn is Nm10/3 conductive yarn. The stitch I default to is a double treble (UK) crochet stitch. I actually taught myself crochet through these tutorials.
I have been trialling different types of normal yarn and have found some just are not resistive. My test is a simple 3.7V battery , resistor and LED and when the yarn is stretched. In the image above you can see the types of yarn I have tried.
Silver – All conductive yarn. Great as a conductor but no resistance
Blue – 80% bamboo 20% wool. No resistance.
Pink (used in video) – 100% cotton. Works best.
Yellow – 100% Acrylic. No resistance.
Pink/White mix – 70% triacetate 30% nylon. No resistance.
Hot Pink (pictured below on soft circut sample) – 50% Acrylic 50% cotton. Works well.
I have used the working trials in creating soft circuits with the crocheted stretch sensor, battery and LED with conductive thread. Below the crochet is sewn onto stretch jersey fabric so the stretch comes from the fabric.
And here are some videos of the 100% cotton yarn in action
How to Get What You Want http://www.kobakant.at/DIY/?p=2022