Wearables

Liza Stark

This second class on the topic of wearables and e-textiles will provide a more advanced coverage on soft sensors and actuators and programming interactions.

Notes

The slides can be found here. Use the slides as a repository, there’s a lot of practical information.

Why we wear

• expression
• communication
• protection

Considerations for electronics in fashion

• application
• durability
• wearability
• washability
• power
• circuit layout

Approaches

Visual:

• LEDs

  Connect LED to Arduino with a 220 Ohm resistor (in parallel only 3 LEDs max. with one resistor)

• Neopixels

  LED strip, address LEDs individually on a microcontroller (you need a microcontroller, cannot use without; download neopixel library for Arduino). Available as strips/rings/matrices/sewable/regular

• Fiber optics

  Light shines in one end and emerges at the other end, quality of fiber determines brightness. Side emitting fibers are also available. Connections are a bit tricky, see slides for documentation; don’t let the light escape at the connection

• Thermochromic ink

  Ink/pigment that reacts to heat (becomes colorless once a certain temperature is reached). Pigments can be mixed with different substrates. To heat the circuit we need a secondary power source because Arduino cannot provide enough. For this we use transistors (drain, source, gate). Keep heating up and cooling down times in mind

Sound:

• Speakers

  Electromagnets: create a fabric speaker. See slides for tutorial on how to make one. You can also make an amp, DFPlayer Mini plays audio files from SD card

Motion:

• Shape memory alloys (SMAs)

  Flexinol (very difficult to make it work apparently). SMAs when heated go to a specific shape (either trained or untrained; untrained shrinks and trained goes into a shape determined by a heating process). Works best with lightweight materials. Liza uses .008 materials thickness (in inches). Use for folding/curling/smocking. Cannot be soldered directly, use crimp beads are very useful. Use the same heat controlling circuit as the thermochromic inks

• Flip dots

  Magnetic ball/bead with one or two coils