12. SKIN ELETRONICS#

Research#

For this assignment I found it very difficult to understand what to test. At first I was attracted by the hair project but I immediately understood that whatever I wanted to create would have been a wearable anyway.

For the moment the e-makeup does not grab me and what seemed to me to be a skin electonics was the tattoo.

What first occurred to me was to lasercut something with the copper tape. In looking for a function for this type of test that was not only aesthetic, I thought of a kind of readable code.

So I tried to create a QR code.

I have not yet figured out if it works anyway I understand that lasering and then correctly attaching such a complex and unstructured code would not be easy.

It would be better to find the way to print on the skin (tattooing) the design.

It would be nice to imagine creating a code that contains useful information such as blood type or genetic diseases. I realize that there is a code for the assistance of this project that could be useless but in case of emergency and unconsciousness the card may not be the most functional thing.

Anyway I decided to create a mask and not being inspired yet, I did a little research first.

An article from ANSA WEB:

Like the chameleons, the new materials change color

A ‘living’ gel made of heart cells changes color at every ‘beat’: it is one of the hybrid materials that will increasingly be used in robotics

The inspiration comes from the skin of the chameleon, which contains crystals that reflect some wavelengths of light, but absorb others.

When the skin is stretched, it alters the distance between these crystals and changes the wavelengths that are reflected and consequently the skin of the reptile changes color.

In the same way it occurred to me that gems and precious stones, as well as simple faceted polymers, refract light creating plays of colors.

HERE an article that explains and recounts the interaction between Light and Crystals and the refraction of that one.

An article on ROBOTIC Science:

A hierarchically patterned, bioinspired e-skin able to detect the direction of applied pressure for robotics

A Soft Touch Measuring and distinguishing in real time normal and shear forces are crucial for slip detection and interaction with fragile bodies. Boutry et al. developed a multilayer electronic skin that distinguished subtle differences in force direction with microstructures inspired by human skin and sunflower floret spirals. They covered the hand of a robotic arm with the e-skin and programmed a controller to stop the automatic downward movement of the arm when a certain amount of force was detected. The resulting sensory feedback allowed the system to respond quickly enough to avoid damaging lightweight objects.

[CREDIT: A. FOUDEH, C. BOUTRY, M. NEGRE, M. JORDA, O. VARDOULIS, Z. BAO/STANFORD UNIVERSITY]

From here I took inspiration for my mask.

I would have liked to add pailettes or crystals to verify the refract of the light, but first it was necessary to receive it.

So I opted to retrieve Christmas lights from Tiger, with 4 euros I recovered 3 meters of nanoled to be connected to two 1.5v batteries.

I thought to use the silicone to be cast on a mask mold that I already had, but the type of silicone that I wanted to try (Smooth-Sil 940) it was not good because it would be pink and not transparent or white. This type of silicone is perfect for creating molds even for food because it does not release toxins.

The mold of the mask has a half-moon shape that led me to consider the idea of shaping the missing part of the face directly on mine with a hand-painted silk fabric. Not having the correct silicone and vinavil glue to reinforce the fabric, I decided to do everything with bio-silicone.

The difficulties arose in investing time to calculate the dosages and cook the bio-silicone which, on the contrary, tended to solidify quickly.

Development#

The first step was to put an insulating film on the mold towards the outer side.

The idea was to brush the silicone layer by layer but the layout was very imperfect and the details of the face like the lips are not clearly visible.

Later I decided to pour the bio-silicone into the mask so as to make sure to get the main features of the nose and mouth.

I made a new casting by first filling the holes and adding the fabric that I had at first molded directly onto my face.

The shutter speeds would have been too long to make sure I get a defined mold. So I decided to adapt it manually with the rest of the mask.

After the first laying and after placing the fabric I inserted the LEDs and tried to see on the face how the fabric part was dressed.

I slightly modified the fabric at the height of the forehead and chin to make it more adherent to the face and I added the first layer of silicone I had done to have in this way a clearer surface even inside since the layer had been laid from the front of the mask.

I brushed the bio-silicone to join the two parts and fix the leds on the part of the fabric.

The choice of the bio-silicone was made according to the tests previously done.

The more rigid the texture becomes, the more the bio-material tends to curl. This is what I noticed.

On the fabric with the bio-silicone only on one side, once dry it began to curl at the ends towards the outside of the mask or rather the side where the bio-silicone was placed.

Also for this reason it was necessary to add a layer inside it.

/*
  Esempi -> Basic -> Blink
  This example code is in the public domain.
  http://www.arduino.cc/en/Tutorial/Blink

  Turns LED on.

  LED is attached to digital pin 9 and to the ground, on LilyPad board.
*/

// void setup() {
  // initialize digital pin LED as an output.
  pinMode(LED, OUTPUT);
}

// void loop() {
  digitalWrite(LED, HIGH);   // turn the LED on 
  delay(100);                       
  digitalWrite(LED, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       
}

Several lilypad leds conncted to pin 9 and the ground in series at the LilyPad board and the computer.

Tips#