For my open project, I crafted two stretchable knitted sleeves that react (by fading LEDs) when the user stretches out their arms.
The project idea came from our class ideation exercise. Sleeves, stretching and relief. One of the core wearability concepts talks about creating wearable’s that are a “successful extension of the body”. For me, I have this habit of standing up and stretching my body. I wanted to recreate this feeling of extension into a material object. Whenever I stretch my arms, the material reacts to my movements and turns on LEDs.
Sketches of different ideas for the final completed wearable.
Loom knitting the sleeves. Every few lines, I would measure the length and determine if it was long enough to move onto the next step.
The next step of the process was adding conductive thread near the bottom rows of each sleeve. I would test the resistant values while I was knitting to determine if there was enough resistance between the beginning of the conductive thread and the end. This process was done for both sleeves.
Next step was to knit a collar to hold the battery and cpx. I measured around my neck, arms, chest to determine how long I would need to knit for. The first step when you’re knitting yarn you’ve never used before, is to knit a swatch. This photo is a 6 inch swatch (not 27 inches).
This is planning out the placement of the LEDs. The sleeves were turned inside out. The LEDs were flipped downwards to avoid any uncomfortable poking and sewed on felt with conductive thread.
This part was fairly easy to put together. The more tricky part was trying to determine value parameter for each stretchy sleeve. Using the Arduino IDE and serial monitor makes it a lot easier to program the CPX.
Final Project Images (and video below)
- Yarn (preferably one colour or a matching colour).
- Loom knitter.
- Knitting needles.
- Conductive thread.
- PVC circuit wires.
- Resistors (200 ohm, 56 ohm).
- LEDs (plus 330 ohm resistors).
- Fabric scissors.
- Felt fabric.
- Li-poly battery (850 mAh).
Reflections & Next Steps
The easiest part of this project was knitting (I had previous knowledge and experience). The most difficult part was deciding on which wires were conductive thread and which had to be PVC wires.
When reading the resistant values of conductive thread, you have to attach one wire at the beginning and one at the end. You need one wire not to interact with the knitted conductive thread parts. It’s not easy sewing and attaching a PVC circuit wire to knitted material.
This is one part that I struggled the most with and I will continue experimenting with different conductive materials and yarn to hopefully avoid using PVC circuit wire for the stretch component.
Next steps, I will continue knitting a sweater to attach to my sleeves.
Resources & Related Works
- Arduino, & Arduino_Scuola. (2016, July 8). Tubolar Stretch Sensor Tutorial. Arduino. https://create.arduino.cc/projecthub/Arduino_Scuola/tubolar-stretch-sensor-tutorial-fdb5c5
- Knit Stretch Sensors. (n.d.). Kobakant. Retrieved April 16, 2021, from https://www.kobakant.at/DIY/?p=1762
- Knit Wrist Sensors. (n.d.). Kobakant. Retrieved April 16, 2021, from https://www.kobakant.at/DIY/?p=4461
- Knitted stretchy cable. (n.d.). Kobakant. Retrieved April 16, 2021, from https://www.kobakant.at/DIY/?p=2245