13 Skin Electronics¶
Inspiration¶
Although this week looks a bit silly, I like these electric henna tattoos by Amrita Kulkarni.
Workflow¶
I'm thinking about making something on my hand. And I'm thinking it should have a certain function. But what could it do? Maybe it could encourage connection between people. It could light up when two people interact. What if I make something that lights up when someone shakes my hand?
I got an old piece of velvet contact paper I had and started sketching some Circassian motifs and thinking how they will go on my hand.
At first I thought about putting a momentary switch on my palm. I stuck the design on my hand and made some handshakes with my sister to test where are the pressure points before I attach the circuit.
I discovered the switch won't work on my palm. But it could work around the middle of the back of my hand. So I changed the design to something like the image on the right.
I cut the design as a whole and assembled the circuit.
I used a Gemma M0 and attached two lilypad LEDs to it. I made a simple blinking light sketch with alternating lights. Below you can find the schematic for the circuit.
Because I used the Gemma m0 microcontroller, I had to install its libraries in Arduino IDE. It's very simple, just search for Adafruit SAMD in the arduino IDE library manager and install the libraries. I found this tutorial very helpful and clear.
This is the code I used:
int light01 = A1;
int light02 = A2;
void setup() {
// put your setup code here, to run once:
pinMode(light01, OUTPUT);
pinMode(light02, OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
digitalWrite(light01, HIGH);
digitalWrite(light02, LOW);
delay(1000);
digitalWrite(light01,LOW);
digitalWrite(light02,HIGH);
delay(1000);
}
I tested out the code and the circuit. I learned to always test test test each step before assembling anything when working with electronics.
The Blinking Handshake¶
Finally, I went around the house to shake some hands.
Material Alternatives¶
I didn't like the velvet contact paper much and was thinking there should be an eco-friendly solution I could try. I searched the internet for homemade FX makeup and found a recipe on Instructables that uses tapioca flour and food coloring. Cool. I followed the recipe and added 30 grams of tapioca flour to 125 ml of cold hibiscus dye bath (to add color) and stirred on the stove until it bacame a really sticky goo.
This is how sticky it was.
I tried some on my hand and it was impossible to control the design. So I made an acrylic mold and filled it with the mix with difficulty.
I also tried to spread some on an acrylic sheet but it kept coming off.
At last, I got it to stick. It completely dried after one week and became like a fragile plastic piece. But one week is more than enough time, I mean no one would wear it that long. I wanted to cut some designs and stick them to my hand when it was still sticky but couldn't do that, so this idea was a failure.
The mix in the mold dried after a week also and broke. I couldn't transfer it to my hand when it was still sticky so this idea was not good as well.
But I loved how the mix felt on my hand. I added a sprinkle of flour on top to make it less sticky. Dad shook my hand and tested the mix and was as impressed as I am. It was holding very good. It got dry after two hours. I think there are good possibilities for this if we can figure how to control the design.
