Color Changing Textile: Picnics and Bees
by sfollmer
MEASURING AND CALCULATING:
Since the thread needs to carry at least 100mA of current to change the ink’s color and the battery is 3.7 volts, we know that the thread will need to have a resistance of 37 Ω (R = V/I).
Using the multimeter to test the voltage and resistance:
the voltage of the battery: 3.6 volts
the resistance in the trace from battery to switch: 13.2 mΩ
the resistance in the trace from switch back to battery: 9.6 mΩ
total resistance: 22.8 mΩ
So…
I = V/R
I = 3.6 V/ 22.8 mΩ
I= 157.9 A
(measured current: 119.3 – 133.4 A)
THE PICNIC:
My initial idea for the fabric was to create a system that would change from solid to checkered when turned on.
However, my first attempt to create a circuit was unsuccessful. I didn’t test the resistance through the length of thread before sewing and I quickly realized that the battery wouldn’t be able to power the circuit.
Sketch:
Setting up:
Before painting:
After painting:
Well, at least the paint works
THE BEE:
Since the first circuit didn’t work, I decided to create a much simpler circuit. This one is of a bee (the on/off switch), the bees path, and a flower.
Before painting:
After painting:
It works!
