I could not test my first ideas for the switch (balloons and static) because of the rainy weather and so I had to improvise the night before the class with what I had. A straw, a power source, the LEDs and a little ATmega chip.
The switch in itself is simple. The Vcc line is closed when a conductive liquid passes through the straw. It then turns on the ATmega chips which makes a row of LEDs alternatively blink. It’s corny but it’s a switch with a little twist.
The voltage had to be upped to around 17v because the Gatorade I was using acts as a big resistor.
Schematics.
v.