Wearable Narratives #3

This week’s meeting focused on handmade sensors and understanding how the different properties of the e-textile materials that be used to create variable resistance. Namely, we used the SliverSpun yarn which consists of 87% combed cotton, 5% silver, 5% nylon and 3% spandex to knit a flex sensor using fingerknitting. While normally I am used to making this sensor using a knitting doll, a knitting mill, or my flatbed knitting machine, the lack of tools led me to improvise and use two-finger knitting as a way of making the sensor. Because of the thickness of our fingers, fingerknitting is usually done with thicker yarns, so to solve the issue of having a very loosely knit sensor, we used the SilverSpun yarn double.

We also made a pressure/bend sensor using conductive fabric tape and the EeonTex pressure-sensitive fabric. Unfortunately, this material is retired, but you it can be replaced by Velostat. Also, one of the students in this group is in China at the moment and does not have access to all the materials that we have at hand, so we also made a second iteration of the pressure sensor using ESD foam that can be found in any electronics packaging (usually when ordering ICs), Velostat, and also tested it with a piece of anti-static APET/CPP from an electronics bag, which was more of an pressure on/off switch, than an analog sensor, but it still worked great.

Lastly, we made a four-way switch using again the stuff we had at hand, like conductive fabric tape, and the Zell RipStop conductive fabric which we heat-bonded with adhesive, the High-Flex silver-plated copper thread from Karl Grimm, and our needles as the point of contact for the sensor. In an experiment to convert this sensor to have an analog reading we attached a felted ball made of non-conductive wool fiber and stainless steel polyester fiber from Bekaerr/Bekinox.