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This reminds me a bit of quadrupole ion (Paul) traps.

These confine charged particles using just electric fields. This is not possible with static fields (Earnshaw's theorem), but can be done with oscillating fields, even with sensors to determine the positions of the trapped ions.

https://en.wikipedia.org/wiki/Quadrupole_ion_trap

If I recall correctly, the principle was also illustrated in Feynman's lecture notes, where a vertical rod supported by a ball joint from the bottom is kept from tipping over by rapidly moving the joint up and down.

"even without sensors"

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