This was an activity some friends from work and I did for STEM night at a local middle school. We used cups with velcro adhered to the sides. We had markers with velcro on them as well. On top of the cup we hot-glued a 3 volt motor and AA battery pack. We had a few different weights to attach to the motor post. When the motor ran, the vibrations caused the cup to skitter around on the paper leaving a loopy shape.
This idea came from something we saw at LIGO Science Saturday in Livingston Louisiana.
