︎

SewSkin

Oct 10, 2021
Duration: 2 days
Material: 
  • 36 gauge conductive wire
  • embroidery stabilizer
  • embroidery hoop 6inch
  • TinyLily starter Kit (including Mini Processor Board, USB Board, RGB LED, Battery Adaptor, Battery, needle, micro-USB cable)
  • Temporary tattoo paper pack
  • PVA roll

This small project is built based on the SkinWire paper.

The SewSkin fabrication process is more complicated than DuoSkin. For DuoSkin, layering the gold foils can create trusted conductivity quality. For the SewSkin, the process of sanding off the coat for 36 gauge conductive wire risks the conductivity, stability, and durability of the entire product. Even though we would test the conductivity of that sanded segment with the multimeter, we still cannot guarantee if there is any coat left unremoved. Any tiny patch of coat left on the wire can cause an unstable connection during application. In addition, sanding makes the wire much more fragile. The wire would break but the left wire is too short to complete this thread. I think I can use Duoskin to complete this lab, but the device may have a bigger surface area.

SewSkin is uniquely suited for body locations with big curvatures and small surface areas, such as fingers, ears. But too much bending would be deadly to those wires.

Sewing the circuit is very challenging for me. Since my conductive wires broke multiple times, and their length was too short to even reach the TinyLily, I need to remove them all and sew with a new conductive wire. This process is very time-consuming and requires a lot of patience. My wire also broke during sanding, so I also need to re-sand a new segment.

For reference, here is the Arduino code for TinyLily:
#include 
#define NUM_LEDS 1 //this is the number of LEDs in your strip
#define DATA_PIN 1 //this is the number on the silkscreen you 
#want to use
#define COLOR_ORDER GRB
CRGB leds[NUM_LEDS];
int brightness = 20; //value from 0-255 to manipulate brightness
void setup() {
  FastLED.addLeds(leds, NUM_LEDS);
  FastLED.setBrightness(brightness);
  pinMode(DATA_PIN, OUTPUT);
}
void loop() {
  for(int i = 0; i < 256; i++) {
    //fill_rainbow(targetArray, numToFill, initialHue, deltaHue);
    fill_rainbow(leds, NUM_LEDS, i, 256/NUM_LEDS);
    FastLED.show(); //update the LEDs
    //delay(100); //optional delay for slower fading
  }
}