This is a homopolar motor.
It’s really easy to experiment with at home. It is driven by the Lorentz force - the force which is exerted by a magnetic field on a moving electric charge. When a battery is placed on top of a magnet, and a wire then connects the top of the battery back down to the magnet, the circuit is complete.
Students in our Summer Schools were making these the other day. This one won the ‘most creative design’ competition <3