Wearables

Please see research here
wearables as physical interfaces with unique characteristics

Output - Actuators

visual
  • LEDs
  • Neopixels
  • Optical fibers
  • Thermochromic ink + heated circuit/code
sound
  • Fabric speakers + amplifier circuits
motion
  • Shape memory alloy + high load circuit
  • Flip dot
  • Flapping wing
  • Mini vibration motors

Sensor - analog slider (from E-textiles week)

software - Arduino code 
 
						iint sensorValue = 0;
//int value = 0;
int pinInput = 0;
int pinOutput = 9;


// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  pinMode(pinInput, INPUT);
  pinMode(pinOutput, OUTPUT);
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // print out the value you read:

// limit the values witin 150/400 range
  sensorValue = constrain(sensorValue, 150, 400);

// convert the analog sensor into a switch, value under the middle of the range will turn off, value above will turn on
  if (sensorValue <= 125);
  {
    analogWrite(pinOutput, LOW);
  }
  else {
  analogWrite(pinOutput, HIGH);
  }

  Serial.print("sensorValue = "); Serial.print(sensorValue); Serial.print(" | ");

  delay(6000);
}

Actuator - SMA Nitinol wire

characteristics

Shape memory alloys (SMAs) are metals that change shape when heated up. They are wonderful actuators in that they are light, silent and can be "turned on" by simply running current through. The shape that they change to can also be set, though this process is a bit more tricky. Flexinol is a particular brand of nitinol, which is an SMA made of nickel and titanium, and is pre-set to contract about 10% of its original length when heated.
The general trends are:

  • All wires take about 1 second to heat up and contract
  • Higher diameter wires have more pulling force than lower diameter wires
  • Higher diameter wires have longer off times (it takes longer for the wire to return to its original, un-contracted shape)
  • Higher-diameter wires have lower resistance and draw more power. Thus, they are more likely to overheat and lose its original contraction abilities. Wires that are 0.006" or smaller can be kept on constantly without fear of overheating.
  • High-Temperature (90C) wires have faster off-times than Low-Temperature (70C) wires REF

Flexinol® Technical Data Sheet

Actuator - optical fibre

Characteristics
The Beginners Guide to Fiber Optics
How to Connect Optical Fibers to LEDs and Sensors
Makezine tutorial: How to Connect Optical Fibers to LEDs and Sensors
MIT Engineers create a programmable fiber
MIT Engineers create a programmable fiber

Project idea

Jellyfish Swimming GIFfrom Jellyfish GIFs
MIT Engineers create a programmable fiber
MIT Engineers create a programmable fiber

re-using the analog slider from week 5
Analog slider
SMA test 1
SMA test 2 + termochromic ink

Thicker wire, requires much more power to move. Ink changes color fast, requires lower trigger temperature than the SMA

MIT Engineers create a programmable fiber
MIT Engineers create a programmable fiber
MIT Engineers create a programmable fiber
MIT Engineers create a programmable fiber
MIT Engineers create a programmable fiber

For further investigation

Conductive foam pressure sensor with biochar bioplastic (or graphene or graphite)
Foaming agents / processes

The Strange Physics of Foam
https://science.nasa.gov/science-news/science-at-nasa/2003/09jun_foam
Foam Making - Prof Steven Abbott
https://www.stevenabbott.co.uk/_downloads/Surfactant%20Science%20Principles%20and%20Practice.pdf
Foam Making - Prof Steven Abbott
https://www.stevenabbott.co.uk/practical-surfactants/foam-making.php
  • acidic + alcaline substances
  • Cellulose fibrils with foam forming surfactants
    https://www.exilva.com/blog/how-to-use-cellulose-fibrils-with-foam-forming-surfactants Cellulose fibrils with foam forming surfactants
  • dry freezing process
  • yeasts
  • mechanical - foaming device for gastronomy - WHIPPING SYPHON

DIY conductive ink + termochromic ink combination
Development of a Screen-Printable Carbon Paste to Achieve Washable Conductive Textiles
https://www.mdpi.com/2673-7248/1/3/22
Self Limiting Conductive Ink 1 - Robert Murray-Smith
https://www.youtube.com/watch?v=5ccgz-4Hzwk
Self Limiting Conductive Ink 2 - Robert Murray-Smith
https://www.youtube.com/watch?v=zyGX-VyXXTQ&t=34s
Self Limiting Conductive Ink 3 - Robert Murray-Smith
https://www.youtube.com/watch?v=PnFLlWeUjPE
(fume silica + glycerol to achieve thicker paste texture)
illusion of motion with light emitters
coil grid for position and pressure sensing

Links

Power harvesting for wearable electronics using fabric electrochemistry

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