5. E-Textiles and Wearables I#

e-textiles from Lara Campos on Vimeo.


“Electronic textiles embed electronics and electrical circuits into textiles using conductive fabrics and/or threads. It describes an emerging hybrid practice that gives new functionality and aesthetics to textile artefacts. These artefacts can live on the body, exist in our everyday interfaces, or explore new digital realms of craft-based traditions.”– Liza Stark

We are in contact with textiles in almost every aspect of our life.I think that in a close future, it’s likely our clothing will be gathering more intimate data about us than our phone or computer. Probably garments will record and transmit data about every move, conversation, breath, and potentially every thought you have. Embedded sensors will be woven into the fabrics we put on our body each day, and this way we’ll be closer to tech.

Though the fact of sorrounding ourselves with technology 24/7 doesn’t encourage me that much, I think there are tons of possibilities and tools to play and create in this topic.

However, I leave for future investigations the idea to work with a metal knitted fabric you can use to isolate your body or even phones, from electromagnetic waves. I believe we can reduce anxiety and rest bestter in case we isolate ourselves to sleep.

Terminology & tools#

• Circuit: path for electricity to flow - paralell circuit: 2 paths/same voltage/current split - series circuit: same path/split voltage/same current

√ all energy in the circuit must be used, if not it will disipate as heat and damage the components

• Electrical current: stream of moving electrons
• Anode: power (+)
• Cathode: ground (-)
• Voltage: force which cause current to flow between two points - measured in VOLTS (V)
• Current: rate at which electrical charge flows – measured in amps (I)
• Resistance: opposition that a material offers to the flow of electric current induced by the voltage. It’s measured in ohms (Ω). Good conductors such as copper have low resistance while good insulators such as rubber have high resistance. Resistance causes electrical energy to be dissipated as heat.


• LED: light emitting diode, as electricity can only flow in one direction. There exist different sizes, colors and voltage needs.

So, a CIRCUIT is a SYSTEM, where each component has a different role. You need to know which ones you need and how to arrange them.

• Multimeter: also known as a VOM (volt-ohm-milliammeter), it is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter can measure voltage, current, and resistance. It is very useful to create your circuit and check that everything works.
• Microcontroller: automate circuits. Arduino is one of them. It is an open-source platform used for building electronics projects. Arduino consists of both a physical programmable circuit board (often referred to as a microcontroller) and a piece of software, or IDE (Integrated Development Environment) that runs on your computer, used to write and upload computer code to the physical board. There are many different types of Arduino microcontrollers which differ not only in design and features, but also in size and processing capabilities.

Arduino Uno is the more common one and easier for begginers. It is a microcontroller board based on the ATmega328P (datasheet). It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with battery to get started.

The Arduino hardware and software was designed for artists, designers, hobbyists, hackers, newbies, and anyone interested in creating interactive objects or environments. Arduino can interact with buttons, LEDs, motors, speakers, GPS units, cameras, the internet, and even electronic devices. This flexibility combined with the fact that the Arduino software is free, the hardware boards are pretty cheap, and both the software and hardware are easy to learn has led to a large community of users who have contributed code and released instructions for a huge variety of Arduino-based projects.


There are some aspects to take into account when thinking about e-textiles:

• Materials. What materials are used? How does it feel?

• Aesthetics. How does it look? How would you describe it?

• Techniques. How was this swatch constructed?

• Interaction. What does this swatch do? How does it work? How do you interact with it?

• Narrative. Is there a story behind this swatch? Can it be used in everyday life?

In terms of MATERIALS, I wanted something soft and clean, as well as a natural fabric. So I chose some pieces of cotton I found at the lab. Also I chose a black conductive fabric, a good conductive silver thread and some electronic tools/devices as leds with embedded resistance and other common resistors. • conductive fabric – black Cu+Ni with conductive adhesive (ZS-260-007-135g) • Karl Grimm High Flex silver conductive thread: polyamid thread plated with silver from Imbut GmbH. • Aligator clips • Bread board • Wires • Multimeter • Iron • Arduino • SMD leds

Oriental – Minimal – Organic – Naughty I wanted to create a nice organic female drawing while add a little bit of naughtyness with the leds and the song ‘can’t touch this’ as output for my swatches.

Laser cutting conductive fabric – sewing with cotton thread & conductive silver thread – ironing – coding Arduino

The aim was to create a swatch with a digital circuit that turn leds on by pressing a push button as well as an analog circuit with a capacitive sensor that turns music on when you touch it.

As brainstorming on a concept for this project, I thought of creating a swatch that can easily be applied to a garment, for example a t-shirt or a jacket, with the idea of creating an interaction between the user and the e-textile, as well as with the context of the wearer. It can be used in everyday life, though you need to unplug it from the microcontroller in order to wash it. With time and washing periods, probably leds will stop working, but they can be replaced taking the old ones and sticking the new ones in the same position.

Design traces#

In the first place, you need to think in your circuit an determine if it would be ANALOG or DIGITAL. When speaking about INPUT you can use a switch and make it a DIGITAL circuit (on/off), or use a sensor and make it an ANALOG circuit (range of values).

• Digital circuit:

I started drawing the woman silhouette in illustrator, which will be laser cutted in conductive fabric which base material is polyester coated with nickel&copper. The fabrics have excellent conductivity in all directions and exhibit excellent shielding effectiveness as well as flexibility.

Then open the file in Rhino and continue editing the paths. I had to convert them from a single brush line to the contour of it, in order to be able to laser cut it. To do this, I used commands such as ‘offset’, ‘trim’, ‘line’, ‘pointsOn/off’, ‘extend’. The ‘Offset’ command copies a curve so that all points on the copied curve are replied on a specific distance from the original curve, and you can do it in two directions; inside (smaller) or outside (bigger) your curve/line. The ‘PointsOn’ command displays control points so you can grab them and modify their location, while the ‘PointsOff’ command turns off control point display. While changing the brush line to its contour I also realized I should have minimum distance in between paths for the conductive fabric not to touch as well as for the paths to be thick enough to avoid breaking when manipulating it till I iron it to the fabric. So I offset the line to reach at least 3 or 4 mm, and then check its thickness with ‘distance’ command.

Also I needed to bare in mind the fact that I should have one positive path and one negative, for the energy to flow correctly and so be able to make the circuit work.

• Analog circuit:

I draw my path with the ‘text’ command with the phrase ‘CAN’T TOUCH THIS’. Then I used ‘Make2d’ to get the contour of the letter’s lines.

In contrast with the digital circuit which has a positive path and a negative path, this has just one path, which is positive and connects two pins (send pin and recieve pin).

This will work as a capacitor or capacitive sensor, that I will explain later on this post.

Laser cutting#

When laser cutting is very importante to reach good cut optimizing the power and speed of the machine acoording to the material you are going to cut. So each material has different parameters. Also it is important top ut some tape on the sides of the material to avoid bending or blowing while you are cutting it.
In this case the parameters were: power 85, speed 2 & PPI/Hz 2000.

One mistake I had, is that I put the conductive fabric the other way round to laser cut it. So the result was a mirror of my circuit. In this case nothing happens, as it was the same for me either way, but if you want to keep your design as you thought about it, be sure you put it inside the machine with the part you want to see looking up. The conductive fabric I used has a sticky white side (made out of conductive glue), where you should take a film from it in order to iron it later on the fabric.

Hard-soft connections#

Embed the circuits -

Once laser cut the paths on the conductive fabric I located them where I wanted to be, trying in the digital circuit not to iron the end of the paths where the leds will be embeded, as they have the conductive part on top, so I should first stick the leds on the fabric and then the conductive fabric on top.

The SMD leds I used have a sticky part as well, and you can take easily the film and stick them where you want. They already have embedded the resistance they need to work.

Digital circuit:#

For the digital circuit I build a switch (on/off). To create it it was very useful to read Liza Stark’s class notes about switches.

• Switches

Pushbuttons + Momentary Switches

These stay open as long as you hold them.

When the switch is in its normal position, the contacts are not touching, so the circuit is open. With a push button, you create a momentary switch that stay closed as long as you hold it by pressing conductive materials into contact.

• Circuit sketch

In order to build it I used a small piece of foam as an insulator material to avoid both conductive materials to touch. I did a small whole on it, which will allow them to touch when you apply pressure in that place. I cutted two circles of the same conductive fabric and sticked them (by ironing) one in the back of the swatch, and other one in a small squared piece of fabric. Also I connected the conductive paths to this circles, one to the positive and the other to the negative one, with a conductive silver thread by sewing it carefully without going to the front of my swatch in order to make it ‘invisible’ and keep it clean of connections/ ’wires’. Meanwhile I sew the small square of cotton fabric (where I ironed the conductive fabric circle) as if it was a pocket on the back of my swatch. Inside it, I embeded a 3.3V battery on top of it, touching the conductive fabric, and on top of it the isolating layer (foam). To understand it better I did a sketch of it.

So this simple circuit tends to be a digital one with an on/off push button.

Analog circuit:#

For the analog circuit I build a capacitive sensor to have a range of values as an input and so play music as the output. To create them it was very useful to read Liza Stark’s class notes about sensors.

• Sensors:

To create your own sensor allows you to customize it, as well as making it cheaper.

To make them, you need to think in what activate them, I mean the input. That could be pressure, distance or displacement of an object in a linear or rotary motion(potentiometer), stretch or bend it.

As I mentioned before, when speaking about INPUT you can use a switch and make it a DIGITAL circuit (ON/OFF), or use a sensor and make it an ANALOG circuit (range of values).

In an analog circuit you can use resistance to get a broader range of values. Resistance limits the flow of current. By allowing more current to get through, you can change the brightness of an LED, the frequency of a sound, or the speed of a motor.

Moreover, it can change because of distance, contact, and surface area.

  • resistance increases over distance (no matter what is the material)
  • resistance decrease when pressure is applied to them (in some materials)
  • resistance decrease as the size of the area for electricity to flow increase

• Capacitive sensor

Capacitors can be sensitive. Within the last decade or so, it has become difficult indeed to imagine a world without touch-sensitive electronics. Smartphones are a prominent and ubiquitous example, but of course, there are numerous devices and systems that incorporate touch-sensitive functionality. Both resistance and capacitance can be employed as means to achieve touch sensitivity.

In this case, the exact value of the capacitor is irrelevant. We are looking only for changes in its capacitance, reached by the finger. But, why does the presence of the finger alter the capacitance? There are two reasons: the first involves the finger’s dielectric properties, and the second involves the finger’s conductive properties. By touching it, we change the dielectric constant, because a human finger has different dielectric characteristics than the air that it is displacing around it.

Actually, human flesh is a good dielectric material because our bodies are mostly water. The dielectric constant of a vacuum is defined as 1, and the dielectric constant of air is just slightly higher (about 1.0006 at sea level and room temperature). The dielectric constant of water is much higher, around 80. So the finger’s interaction with the capacitor’s electric field represents an increase in the dielectric constant and hence an increase in the capacitance.

Therefore, by connecting the path with the conductive fabric + conductive thread to an Arduino, in between two pins, you can get the values of it (Serial Monitor) and so you create a capacitive sensor. Then, you can use these values and measure its alteration so you can code a reaction to this changing values in order to have an output of it.

• Circuit sketch

Circuit connection & coding#

I’ve tried the conductivity of both circuits with a multimeter, as well as I used a bread board to connect my analog circuit with the amount of resistance I needed (which I located in between the send pin -3- and the receive pin-5-), as well as connecting it to the arduino. To connect it I used wires and aligator clips to be sure that everything was in contact. Once connected, I download the Arduino and tried if it works as I read the monitor serial values. As long as it gives you values and they change when you touch the sensor, it is working. Also I try it with the digital circuit, with a blink code for leds that you can find out in ‘file’/ ‘example’/ ‘basics’/ ‘blink’. Also I chose the type of board and port I was using.

Then I started coding the sensor of my analog circuit with help of an instructable I found on Instructables

It was pretty short, though I was just getting started with this software and a little bit confused with its terminology.

DigitalWrite, delay, Serial.Println, Serial.begin and pinMode where the coding terminology I used and learned. As well as ‘int’ when you declare the use of one pin, e.g ‘int led=13’ as to turn it on ‘DigitalWrite(led,HIGH)’ and to turn it off ‘DigitalWrite(led,LOW)’.

This is the code:

#include <CapacitiveSensor.h>  

CapacitiveSensor   cs_5_3 = CapacitiveSensor(5,3);  

int count = 0;  

int debounceTime = 1000;  

int lastMillis = 0;  

void setup()                     

{ cs_5_3.set_CS_AutocaL_Millis(0xFFFFFFFF);     


 Serial.println("Serial Started");  


void loop()      

    long start = millis();  

    long total2 =  cs_5_3.capacitiveSensor(30);  

    if(total2  > 500){  

      Serial.println("Play Music");  







Then with help of an instructor of the lab, I programmed the output with python, so that the music can be played from my computer. To make it work you need to have the swatch connected to you computer by the Arduino.

• Python

We created another script in python that is connected in serial with Arduino. So when Python reads the character “&” it orders the computer to play the song which is saved as a mp4 file.
The script is the following:

import serial, os, subprocess  

audio_file = "/Users/Lari/Documents/Arduino/CapacitiveSensor/123.m4a"  

serialPath = '/dev/cu.usbmodem1421'  

serial_port = serial.Serial(serialPath)  

while serial_port.isOpen():  

    a = serial_port.readline()  

    print a  

    if '&' in a:  

        print "Got IT"  

        return_code = subprocess.call(["afplay", audio_file])  

For future improvements, it’s better to plug it to a small speaker and use an Attiny microcontroller, so that it can be embedded to the garment and be almost ‘invisible’. Though in this case, it would be necessary to unplug every device before washing it.


To have a nice swatch I decided to put it into a frame. To build it, I cut a long wood frame and put it together with a stapling machine that with pressure attach metal staples into the wood pieces. Once I’ve got the rectangular frame, I stapled the swatch on it.

The E-Textile Summercamp‘s Swatchbook Exchange is a platform for sharing physical work samples in the field of electronic textiles. The exchange wishes to emphasize the importance of physicality and quality workmanship in an increasingly digital world.