IAT 320 Body Interface: [Week 8] Soft Circuit Assignment Prototyping

We decided to create the headband idea. First, we came up with a material list:

LEDs
conductive thread
resisters (220ohms for the LED and 10k for the switch jumper)
wires
felt
metal clasps and buckle (to attach different accessories to the hair band and hooks to attach wires to the arduino board)
elastic hair band (this will create the pressure to activate the soft switch when it is worn)

The circuit layout was based from the simple series circuit shown in lab. However, there were many more considerations when sewing a circuit instead of building a circuit with wires on a breadboard. For instance, the material we had was a stretchable hair band. We did not want to sew conductive thread directly on the elastic material because the thread cannot stretch and will break under strain. Thus, our circuit will be broken. This was resolved by sewing the circuit on pieces of felt, which were later sewn onto the hair band with non-conductive thread. Also, we had to conceal the soft switch and wires to prevent contact with our head. We made a simple felt pouch that is open on the two ends to easily attach wires to the switch and replace the switch.

In our idea, we wanted to be able to interchange the accessory on the hair band. This was implemented by using metal buckles that can be sewn and connected in the circuit.

Flower that can be attached to the circuit.

Draft Prototype

For the draft prototype, the soft switch was made of a piece of felt with a hole in the center sandwiched between two pieces of tin foils. When we tested this switch, it was not sensitive enough. The switch activated only if we pressed on it. Therefore, we created another type of soft switch with felt and conductive thread. Instead of using the two tin foils as conductive surfaces, we sewed conductive thread in a zig-zag pattern on two pieces of felt.