5. E-textiles¶
Research¶
When searching for images related to e-textiles, what caught my attention were items like those worn around the neck or earrings—things that are wearable. I had understood wearable to be almost the same as this. Wearables refer to clothing or fashion and accessories that are worn. E-textiles, however, are techniques that can be used not only in sportswear and fashion but also in fields like health and sound.
"While doing embroidery, I thought it would be interesting if the embroidered design itself could light up." I'm thinking of creating clothing or a stole that randomly lights up around the neck area. "First, I referred to the workshop I conducted just last month when I exhibited at the Tokyo Maker Faire, where we sewed LEDs with conductive thread to make them light up. I believe I understand simple circuits."
References & Inspiration¶
When working on the assignment, Nuria showed me her sample and mentioned, "Yuki, perhaps you could write a message with embroidery." This sparked an idea for the task involving a single piece of felt:
I realized I could create a story.
"What came to mind when I saw the assignment was to write a letter using embroidery. It just so happened that it was both my and my son's birthday, so I thought a glowing fabric letter could be fun to receive."
"At that time, there was also a presentation of a work by our household's sewing machine, Tajima. It featured a butterfly sewn with conductive thread that lights up through an algorithm. It’s truly a hot topic right now."
Process and workflow¶
Step 1: Sensor Differentation¶
Nuria first drew a picture to explain what I should do for the assignment!
1. Digital buttons¶
At the Maker Faire, I created glowing LED badges and had leftover ghost-shaped felt pieces that were laser-cut. I decided to combine two of these felt pieces to make a button. Using conductive copper foil tape, I created electrical pathways on each piece."Look, the current is flowing!"
2. Pressure sensor¶
At Fab Lab León, used the laser cutter to cut stylish fabric into components for a pressure sensor. I designed the LED to light up as the eyes of a pink ghost and included a resistor in the circuit. For the sensor, I adhered conductive copper foil tape to the back of a decorative ribbon to create a conductive pathway for the electric current. But it didn't light up! Why? It didn't light up! Check it!"
b: Disassemble the pressure sensor and check the current flow inside.
How to measure the conductivity¶
How to measure the conductivity, use "multimeter". If current is flowing, a sound will be emitted.
c: Put the cover on the sensor and check the current flow while pressing the sensor. The multimeter shows "0."
e:Check the current on the adhesive side of the copper foil tape → The ammeter shows "0." It was found that the adhesive side of the copper foil tape is not conductive!
a:The adhesive side of the copper foil tape is not conductive. So, how can I make the current flow?
b: Add more copper foil tape to properly connect the path for the current to flow.
d: It worked!
Next, create a sensor using Velostat. Layer the components in the order of 1 to 4 mentioned above, and sew them together. I've connected the braided conductive thread to the sensor! Great progress!
3. Strech sensor¶
Video Kumihimo
That's awesome! It sounds like Nuria's manual braiding machine and the use of conductive thread could be a great asset for my projects.
The current's magnitude changes with the stretching and shrinking of the conductive braided cord. This is a great way to create a sensor that responds to physical pressure or movement!
When I pull the braided cord, the current becomes smaller, and when I loosen it (let it slack), the current increases. This change in current can be used to measure tension or pressure variations.
Step 2: Prepartion for Arduino¶
With Adrian's support, I welded the parts onto a thinner plate than the Lilypad I had. The key to the welding process is to heat the connecting parts with solder and use the residual heat to melt the solder. Then, place the components that I want to connect onto the melted solder.
Then, download from the Arduino homepage and set up the program.
Download from the "Software" tab on the Arduino homepage to use the Arduino program.
Step 3: Integration of the Switch & Sensor and Output¶
Design a circuit using alligator clips. Use a braided stretch sensor to check how the current changes based on the degree of stretch
Create an Arduino code for the LilyPad to measure the voltage at the A2 port and output it to the serial port.
Instead of using alligator clips, you can create a circuit by sewing with conductive thread.
*Fils: Code of Arduino
I used the stretching and shrinking of the conductive thread to change the way the LED lights up! That's a great application of my sensor.
Video Arduino
When the stretch sensor is relaxed, the serial port shows a high value, such as 4.95V. When pulled, the values decrease to around 1.06V or 0.92V. When relaxed again, the values rise back to around 4.93V.
Video Strech sensor
Measure the resistance with a multimeter as well. Set the multimeter to the Ω symbol. When simply connected, the resistance is around 90Ω. The resistance decreases to around 50Ω when pulled and increases to around 100Ω when stretched.
Fin.