5. E-textiles¶

Week 5. I am still alive… E-Textiles!! Amazing! This subject is one of my favourites of the program. All my life I wanted to understand how wearables work and now I will know! 😊

Inspiration¶

Inspiration? All! I really enjoy this subject. Liza’s and Emma’s presentation were amazing! They started introducing a bit the story of wearables and immediately she gave a brief but clear presentation about circuits and how they could be used in textiles

Then, this explanation made me remember about some basic concepts necessary for this new subject:

All electrical energy in the circuit must be used
Resisting materials are sensors: By allowiwng more current to get through, you can change the brightness of a LED. The frequency of a sound.
When selecting the different materials for wearables (Fabrics, Threads), we shall evaluate: resistance, Stretchiness, Solderability, Feel , Thickness.
Secure loose threads
Sensors can be Digital (Switches) or Analogs (Sensors)

For further details and alternative explanations, you can check in the webpages of my friends Emma and Anna :)

Now, with this brief information I think I am a bit closer to understand how this jacket works that is really inspiring for me:

Process and workflow – Anti-Stress Glove¶

Now.. as I said, as of the moment I am feeling a lot of pressure and also a friend had an injury in his hand. So these two events that are not connected, inspired for this week’s assignment. I thought maybe I could design a glove that turns on a LED when you press it (same principle as anti-stress balls) and also, it can help my friend with his physiotherapy so when he is able to close his hand, he will be able to turn on the LED. Moreover, this same gadget could be used as a toy in the same way that buzz lightyear used his laser beam

Buzz Lightyear's laser beam

For this assignment I used:

3mm Black Neoprene
1 Red LED
1 Battery 3Volts
Conductive thread
1 Piece of velostat (5cm x 2cm)
1 clip
1 pin

So all started with it a sketch: It is a good idea to sketch the circuit design before, test in in the breadboard , to discover any mistakes before the sewing process. For this assignment we needed to include 1 switch and 1 sensor. In my case, the sensor is the velostat that changes its resistance when is pressed, and the switch is the pin that closes the circuit when you wear the glove.

Then I replicated this circuit in the breadboard and test it with the variable resistor to prove that the LED will effectively change its intensity by varying the resistance.

When it worked, I replaced the variable resistor with the velostat connected with conductive thread and proved that the system effectively worked out!

Working Circuit with Velostat

For the glove design, I started taking a sketch of my hand and to make it more “fashionable” I tried to make a glove similar to the one Thanos, a villain from the Marvel Universe, used to collect the infinity gems to destroy the universe.

Thanos Glove

Then replicated in Rhino ¹ and then got the design thru laser cut in black neoprene. The parameters for laser cut were

parameters for laser cut - 3mm Neoprene

Power: 20, Speed: 1 and PPI/Hz: 1000.

Finally I started to sew the circuit with conductive thread in the glove with special care that there were no short circuits and that the thread is well separated. The velostat was sewed in a foam material so that it has a similar feeling when you press a stress ball.

Finally I used a clip to secure the battery and now the Anti-Stress glove is ready to be used!!

Results¶

Again, I am really proud of me and this week's assignment as I have integrated new knowledge into a really fun device, that will definetly help me whit the potential stress I would experience in the next weeks. If I feel stressed, It will be time to turn on the red LED 💡🚩

Anti-Stress Glove

AnalogRead and Code Example¶

In order to measure the data with AnalogRead in Arduino, I connected the velostat with alligator clips to the breadboard using the same circuit as before , where the intensity of the LED is determined by the value of the resistor. Then, I programmed in Audrino the following code in order to measure the voltage of the led as the resistor value is changed "(Setting Pin 27 as the input signal - blue color wire in the below video)".

#include <analogWrite.h>

int LED = 13;
int Sensor = 27;
int treshold=0;

// the setup function runs once when you press reset or power the board
void setup() {
  pinMode(LED, OUTPUT);
  pinMode(Sensor, INPUT);
  Serial.begin(9600);
}

// the loop function runs over and over again forever
void loop() {

  int SensorReading = analogRead (Sensor);
  Serial.println(SensorReading);

  if (SensorReading>treshold) {
    analogWrite (LED, 50);
  }
 else {
  analogWrite (LED,255);
  }

Then in the following video it can be seen how diferent values were obtained as the velostat is pressured, confirming that Arduino is collecting different values as the Resistor is caried.

AnalogRead in Arduino

Thank you Petra, Ana and Josep once again!

Fabrication files¶

File: Sketch of the Glove ↩

Last update: 2023-03-02