aluminum foil serves as capacitor plates rubber insulation
Super Simple Electrostatic Motor
You can use any electrostatic source to charge the foil capacitor plates. I find it takes very little effort to generate enough charge difference to get this spinning. I use a version of leny r's PVC generator (http://home.earthlink.net/~lenyr/stat-gen.htm) To take the mystery out of the capacitors (glass jars with foil), I remove them for my students and simply hold the charged cotton on one side of the motor and the charged PVC on the other - which causes the motor to spin. To charge the materials, just rub them together until you feel the hairs on your hand start to stand up.