Step 1: Materials Required
2) Fabric paints
3) LEDs(colors of your choice)
4) 3V coin cell battery
5) Conductive thread(Silver plated nylon conductive thread and a low resistive conductive thread)
6) Normal thread and needle
7) Elastic battery holder(or any coin cell battery holder)
8) Tiny pieces of conductive fabric
9) Transparent cello tape
10) A bead (or something similar)
12) Round nose plier
Step 2: Making the Outer Cover Along With the Variable Resistance Part
I painted some stars on the second side of the cloth. This forms the backside of the bag.
Step 3: Second Layer-The Circuit
‘+’ and ‘–‘ corresponds to positive and negative from the battery (will be shown in the coming steps).
Step 4: Placing LEDs
Step 5: Make Elastic Battery Holder(optional)
To make this elastic battery holder:- Take a piece of elastic just enough to wrap the coin cell battery. Mark the points where the center of the battery on both sides touches the elastic. These will form the two terminals (+ and-). Stitch a small piece of conductive fabric using conductive thread to these terminals (inside the elastic battery holder). Conductive fabric is used just to ensure better connection.
Step 6: Completing the Circuit
Don’t forget to leave a length of thread, dangling and wounded around a bead, from the negative of the second LED(here, the yellow one).The length of the hanging bead should be such that it can touch both ends of the variable resistance part.
Since the variable resistance part is in the upper layer, sewing a small piece of conductive fabric to the end portion will strengthen the connection between the layers.
Step 7: Sticking the Layers Together
Now the cloth with circuit stitched on it is upside down on the inside of the bag. To keep the cloth in place, I used transparent cello tape over all the 4 sides and also stitched the four corners with the first layer. This should hold it in place.
Step 8: That Is It!!!!!!!
I was a student intern at Ammachi labs when I was introduced to soft circuits. I wanted to start with a soft circuit which was simple but could be helpful in showing some basic electronic principles.
We have not included any resistor because; the conductive wire itself provides a resistance per unit length. This is enough to protect the LEDs.
You can see that for the same voltage, different colored LEDs glow with different brightness.
This model can also be just filled in with some cloth or cotton to get a cushion with an electronic circuit on it.