Pressure switch knit

Credits: Katharina Bredies, Pauline Vierne for Design Research Lab, UdK Berlin

Year of Invention: 2014

Description:
This knitted fabric sensor has been made with a double bed linear knitting machine.
The parts in relief are created by using tuck stitches technique to obtain two conductive and isolated sides.
When you press / sit on one of the points where conductive threads cross, the electrical switch is closed and the electricity (low voltage) flows.
There were been used two different kinds of conductive threads : one highly conductive, made of copper from Karl Grimm and another one, silver plated , from Statex Shieldex, with resistive specifications.

copper thread :
High Flex 3981 7×1 from Karl Grimm
Kupfer blank (copper bare)
2,3Ω/m

silver plated thread :
235/34 2-Ply HC+B from Statex Shieldex
Polyamid six filament yarn
99% Silver (metal plated)
100Ω/m

Due to such resistive component we can get different resistive values. Because of them it is possible to determine the position of the contact.

On this piece we can use six different pressure sensors areas (lines), each of them with nine « switches ».
All the six pressure sensor areas are connected to the Analog inputs. They can be programmed together or individually according to the chosen scenario.

For the exhibition in CeBit, in Hannover, March 2014, the sensor was included in a smart-home context. The idea then was to have a visible lighting effect while someone was sitting on the sensor. So four areas triggered a blink effect while the two left were about a fade effect.
Eventually this fabric sensor involves our relation with our light – and thereby our energy – consumption. How can our home devices be more responsible and related to our real needs ?

Link:

Dimensions: less than 20x20cm

Inspirations/References: Knitted researches from textile designers at the Design Research Lab : Katharina Bredies, Hannah Perner-Wilson, Sara Diaz Rodriguez (if I miss some we should ask Katharina)

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Impression