I was just hanging out at Al Lasher’s Electronics in Berkeley when the proprietor Bob showed me this little gizmo. It’s the creation of one of his customers and is definitely the simplest DC motor I’ve ever seen. An AA battery sits on top of a couple neodymium magnet, and a coil of wire balances on top of the positive pole of the battery. Once it’s set up the motor spins right up.
I can’t think of a motor that’s more simple and elegant than this one. Can you?