5. E-textiles

Learning outcomes

• Research skills: the participant has acquired knowledge through references or replicating existing projects
• Design skills: the participant understands how to produce soft circuits and sensors
• Fabrication skills: Learn how to embed electronics on fabrics, study soft-hard connections
• Process skills: Anyone can go through the workflow, understand it and reproduce it
• Final outcome: The assignment is assembled and either complete or tested

Student checklist

• Build at least one digital and one analogue soft sensor, using different materials and techniques.
• Document the sensor project as well as the readings got using the AnalogRead of Arduino
• Integrate the two soft sensors into one or two textile swatches using hard soft connections
• Document the circuit and its schematic
• Document your swatches / samples
• Upload your arduino code as text
• Upload a small video of the swatches functioning
• Integrate the swatch into a project (extra credit)

Assignment from Anastasia

• Make one digital and one analog electric device that gives an additional value for the car seat driving or riding occasion.

• What about LED lighting buy buttock left and right motion switch as the digital switch, and three pressure sensors settled along spine indicating values as the posture condition as the analog switch?

Research

Since my focus is development of seat which supports human health, I have been looking looking around force sensor made in thin layer. In these days, we can even find some with 3 axis force sensing capability. I am curious about developing these cutting edge sensors with low cost to implement variety of values into vehicle seat.

Here under are the examples of cutting edge thin sensors;

3-axis force sensor

Hybrid 3 axis force sensor

3 Axis Fully Integrated Capacitive Tactile Sensor

I am also very much interested in developing seat fabric which can sense some simple pressures to indicate posture image or entertain drivers and passengers.

In this week, I will try to make fabric which can sense some pressure change.

Process and workflow

Making circuit for Pressure sensing

Thanks to Rico's advice, I learned about basic ARDUINO coding and modified an example pressure sensor circuit into "three sensors' version".

Firstly, I made the account for TinkerCAD to play with electric circuit.

Here under is an useful explanation about making "force sensor circuit" in ARUDUINO-UNO.

Three pressure sensor making in TinkerCAD

Here under is the pinout diagram of ARDUINO-UNO which I will use this week.

By modifying example Force Sensor ThinkerCAD with code, I made "Three Pressure Sensors" in ThinkerCAD.

The three LED should light on same amount by applying same pressure shown in the Voltage meter, but it does not.

Here under is my first coding.

My first ARUDUINO coding is not good in terms of "else if" meaning. "else if" code will not work properly in several sensors with several force (voltage) values. I should focus one sensor at a time.

Here under is the modified coding focusing one sensor at a time for "else if" coding.

Then the Model in ThinkerCAD works correctly as follows; LED lights as the value of force (voltage).

Above coding could be much simpler by utilizing "INT" coding as a formula. following coding was quickly made by Maki(my wife) who used to program C coding.

Three pressure sensor making with actual ARDUINO-UNO

material

• resistance 300Ω
• resistance 10kΩ
• LED RED

I made "Pressure Sensor circuit" with actual ARDUINO-UNO.

Confirmed my ARDUINO coding works with selling pressure sensor.

Video>>

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I also confirmed that the selling bending type force sensor shows very high sensitivity. I would like to study how this type of input occurs in the developing seat.

Video>>

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In order to measure electric characteristics of materials, multimeter is a very important tool. Here under is an useful explanation about "How to use Multimeter"

Digital Sensor

Following Anastasia's recommendation, I firstly made digital switch to detect the left-right hip motion.

material

• Copper tape
• Packing foam
• Jute fabric

Analog Sensor

Following Anastasia's recommendation and my curiosity of making fabric which senses pressure change, I decided to make pressure sensor utilizing Jute fabrics' fiber pattern.

material

• Copper fabric
• Jute fabric
• Velostat

electric resistance of each fabric:

copper fabric: 0.5Ω

Velostat: 70-180Ω by length change

sewed Velostat with copper fabric: 155Ω

Firstly, I confirmed that fabrics contacting both side of Velostat as sandwich structure has too little resistance with very light touch which does not work as force sensor in my seat.

force sensor sandwich Velostat with both side copper fabric - with my AirPods Pro(57g) on : 115Ω - with 2kg training ball on:

Then, I tried to make holes by pulling off every each other fiber from the Jute fabric which might become the physical resistance.

Copper fabric

Jute fabric

Pulling off every other fibers from Jute fabric

Copper fabric with Jute fabric

1st trial test how Jute made grid works as the physical resistance

Video>>

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Yes! Physical resistance of Jute fabric of which every other fibers were pulled off works very well for the force sensor!

Then, I made a mistake to spoil this physical resistance condition by sewing it.

The physical resistance does not work by the strong compression pressure of sewing machine. See all LED light up as soon as connecting the electric lines.

I decided not to sew the Velostat layer against the other copper layer but only cover by Jute fabric to fix the relation between both copper fabrics.

Sewed Jute (pulled off every other fiber) against Copper fabric.

Put sewed Velstat with Copper fabric on.

Place Velstat side against the Jute grid(pulled off every other fibers).

Then cover by the Jute fabric by sewing only the edge.

Here under is the Jute fabric based force sensor explanation video.

Video>>

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electric resistance of "jute grid layer installed force sensor" with 2kg ball: 160Ω

weekly assignment

Check out the weekly assignment here or login to your NuEval progress and evaluation page.

about your images..delete the tip!!

1. Remember to credit/reference all your images to their authors. Open source helps us create change faster together, but we all deserve recognition for what we make, design, think, develop.

2. remember to resize and optimize all your images. You will run out of space and the more data, the more servers, the more cooling systems and energy wasted :) make a choice at every image :)

This image is optimised in size with resolution 72 and passed through tinypng for final optimisation. Remove tips when you don't need them anymore!

get inspired!

Check out and research alumni pages to betetr understand how to document and get inspired

• Soft tools - Stephanie Vilayphiou - GreenLab

• Booklet & veggie moisture sensors - Kae Nagano - FabLab Kamakura

• Knitted samples - Alice Sowa - Icelandic Textile Center

• Final project trajectory - Ieva Maria Dautartaite

Add your fav alumni's pages as references

References & Inspiration

"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."

• Two images side-by-side

• Image reference

centered image with credits/reference

• Download reference

Links to reference files, PDF, booklets,

about your images..

1. Remember to credit/reference all your images to their authors. Open source helps us create change faster together, but we all deserve recognition for what we make, design, think, develop.

2. remember to resize and optimize all your images. You will run out of space and the more data, the more servers, the more cooling systems and energy wasted :) make a choice at every image :) This image is optimised in size with resolution 72 and passed through tinypng for final optimisation.

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Tools

• Arduino UNO
• Arduino IDE

Process and workflow

My sketches are ...

This schematic ¹ was obtained by..

This tutorial ² was created using..

footnote fabrication files

Fabrication files are a necessary element for evaluation. You can add the fabrication files at the bottom of the page and simply link them as a footnote. This was your work stays organised and files will be all together at the bottom of the page. Footnotes are created using [ ^ 1 ] (without spaces, and referenced as you see at the last chapter of this page) You can reference the fabrication files to multiple places on your page as you see for footnote nr. 2 also present in the Gallery.

Code Example

Use the three backticks to separate code.

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
}

Results

Video

From Vimeo

Sound Waves from George Gally (Radarboy) on Vimeo.

From Youtube

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Fabrication files

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1. File: xxx ↩

2. File: xxx ↩