Simple device with 2 ping-pong balls on an insulated rotor works with next principle:
There are ions in air, opposite charged as ions inside of ping-pong balls. Moving ions from air neutralizes on the smooth surfaces of ping-pong balls (as on the Steel wall in previous detailed explanation). Ion formation and neutralization is continuous with DC in open space.
Moving neutralizing ions produces ZPE thrust, thrust hangs from little details (speed, direction and intensity of neutralizing ions). This thrust is in detail explained here: