Finger Bend

Finger Bend is a sensor created to find a way of making finger bends inside of a glove, control light and sound.

I am controlling the brightness of the LED by bending my finger. The more I bend it, the stronger the light.

The idea behind this glove is to then connect it to a body suit with other eTextile sensors for Immersive Audiovisual Performances.

What inspired me to create this project was the vision of performing freely through body movements. It is our innate interface. From my view, it is the obvious tool, instead of a trackpad, mouse, tablet, controllers, joysticks…

Inspiration: KOBAKANT’s sheath bend sensor.

Finger Bend was create for the E-Textile Summercamp’s Electronic Textile Swatch Exchange

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.

I also posted it on my website: https://willpowerstudios.com/tech-lab/finger-bend/

Materials:

× Stretch Piezoresistive Conductive Fabric (https://www.lessemf.com/fabric1.html#11321)

× 2nd Non-Conductive Fabric (top fabric)

× Copper or Other Low Resistance Conductive Thread (from Karl Grimm)

× Stretchy Jersey Fabric (online or textile shops)

× non-conductive thread (online or textile shops)\

× 2 Male Pins

Tools:

× Sewing machine

× LED

× Breadboard

× Computer with arduino and the library for the microcontroller* you are using if it is not yet installed

× USB cable

× Lighter or heat gun (for shrink tube)

Examples of Microcontrollers: Arduino Uno / Nano / Teensy / ESP32

Everything needed.

Cut the stretch jersey fabric to the length of your finger from the knuckle to the beginning of your nail and width of ~ 8 cm.

Cut a piece of stretchy piezoresistive material and top fabric, both at the same size, similar to the top left photo.

Place piezoresistive stretchy fabric in between the base and top fabrics.

× Circle pin around copper thread

× Slide it through shrink tube

× Shrink it with heat gun or lighter to tighten it around the copper circle that you made around the male pin

× Do the same with the next thread

How to test it:

Connect each copper thread pin to an alligator clip.

Clip their opposite side to multimeter nodes, using the ohm measurement.

Observe the change in ohms as your finger bends.

Make sure the copper threads do not touch 😉

The Longer pin of the LED goes to pin 4 of the board.

// WILLPOWER @ Swatch Exchange 2021

#define LED_BUILTIN 13

#define LED 4

int bendSensorValue;

int light;

// the setup function runs once when you press reset or power the board

void setup() {

Serial.begin(9600);

// initialize digital pin LED_BUILTIN as an output.

pinMode(LED_BUILTIN, OUTPUT);

pinMode(LED, OUTPUT);

pinMode(A0, INPUT_PULLUP);

}

void loop() {

bendSensorValue = analogRead(A0);

light = map(bendSensorValue, 740, 840, 255, 0);

light = constrain(light, 0, 255);

digitalWrite(LED_BUILTIN, light);

digitalWrite(LED, light);

Serial.println(bendSensorValue);

}

/*

All Finger Bends are a bit different in terms of the data they are generating, so you may have to calibrate yours.

To do this, after you uploaded your code to your microcontroller, open the Serial Monitor in Arduino and compare the numbers between the highest and lowest… basically when you finger is straight versus bent.

Replace these numbers in the map function from 740, 840 to your numbers.

Keep playing with them until you get the result desired.

( the code is also on github: https://github.com/WillpowerStudios/FingerBend ) */

Bend your finger and watch the light change.

You can use it for lights, visual art animations, motors, sound, and whatever else you desire to control with your finger(s).

The actual project eTextiles Swatch Exchange 2020 Book !