Personal air-filter for use in the Dentist's chair

Levoit core mini with “cone of shame” made from duct tape. You'd hold it on your belly and point it at your nose/mouth, leaving room for the elbows of the dentist. And back home after the dentist, the cone of shame can be removed an the wee thing can perform its normal duties.

The plume of fresh air is OK at 12 inches distance, but it is going to pull adjacent dirty air to your face as it works - that's because of the Bernoulli principle (nice video, heh?).

Needing to reach in through the duct tape for the on/off/speed button is one constraint on that improvised duct-tape nozzle. The rechargeable 12 volt battery at full speed will go many hours, I think.

Edderic Ugaddan's LaminAir is better because the filtered air is pushed out over through a larger surface area and therefore more slowly. That means the air is not shooting past the head of the wearer/holder and doesn't have that Bernoulli effect going on.

Edderic reminds me that I can run some tests on the air flow. Have a candle burning upstream, and use a PMS7003 particle counter to determine how much has been scrubbed out of the air at select distances from the fan.

CleanAirCrew has page on ad-hoc portables, too: https://cleanaircrew.org/personal-air-filters/