Light dependent hat

I have decided to make a had that expands with the intensity of light. In theory, it is simple. I need two phototransisors, a DC motor, and a mechanism that expands radially.

Things to consider/ experiment with:

• which points need to be fixed, and to what
• length and number of parts to get optimal change in diameter
• hot to actuate without moving motor
• power supply/ battery

Features I will add once the basics are down:

• a sensor (heat or proximity) to determine when the hat is being worn
• solar cells to elimnate power supply
• adjustment to direction of light, not just intensity