Arduino board, Resistance, LED, Wires
I decided to use a paper and graphite(conductive material) as a switch.
First, I built a simple circuit with LED, and checked if it works.
With pencil, I drew two points and connected them to make current flows from one point to other point.
To check the LED brightness, I drew 4 lines with different length.
The shorter length, the brighter light.
The longer length, the dimmer light.
Which means different length can control the strength of brightness.