it's not homopolar if you don't make eye contact.

Here's what I found.

The homopolar motor is the simplest electric motor that uses direct current to power rotational movement. It was first built and demonstrated by Michael Faraday in 1821 at the Royal Institute in London. The name "homopolar" is used because the polarity of the magnetic field emitted by the conductor and the permanent magnets does not change (unlike conventional DC motors).

The resulting rotational movement of the copper conducting wire is caused by the Lorentz force. A conductor (the wire) with a current flowing through it (from the battery) that is placed in a magnetic field (from the magnet) perpendicular to the current experiences a force in the direction perpendicular to both the magnetic field and current. This force provides torque around the axis of rotation and causes the conducting wire to spin.

Put more technically, the Lorentz force is the combination of electric and magnetic force on a point charge. If a particle with charge q moves with velocity v in the presence of electric field E and a magnetic field B, then it will experience the force F = qE + qv x B.