[M T]

I recently discussed a study where when they introduced a 1% gap in a N95 mask and a surgical mask, the effectiveness at filtering aerosol particles plummeted (for N95, down to 59%, and for surgical down to 10-15%, IIRC).

Gaps are bad.  Your exhalation will go out the gap.  Inhalation may be a little better than that, but depends on how big the gap is.

But, most masks I see in use have gaps. (Bandanas probably are no better than face shields.)  They probably help for LARGE droplets (2x hair diameter) that don't aerosolize.  But everything 100 micron or smaller evaporates & aerosolizes before it falls to the ground (ok, 100micron only aerosolizes at <50% RH).

But, I sympathize with the issue.  A facemask could have fabric attached to it to go around the head and then drape down to the torso.  That has lots of surface area, so the air draw wouldn't be hard.  But it would tend to be hot and stuffy. 

Add a filter to that with a fan drawing through that filter.

You might look like Buck Rogers....

There are also full face masks that were intended for snorkeling. There are designs for adding filters (N95, etc.), but these masks will be very hard to acquire.

[M T]

I recently discussed a study where when they introduced a 1% gap in a N95 mask and a surgical mask, the effectiveness at filtering aerosol particles plummeted (for N95, down to 59%, and for surgical down to 10-15%, IIRC).

Gaps are bad.  Your exhalation will go out the gap.  Inhalation may be a little better than that, but depends on how big the gap is.

But, most masks I see in use have gaps. (Bandanas probably are no better than face shields.)  They probably help for LARGE droplets (2x hair diameter) that don't aerosolize.  But everything 100 micron or smaller evaporates & aerosolizes before it falls to the ground (ok, 100micron only aerosolizes at <50% RH).

But, I sympathize with the issue.  A facemask could have fabric attached to it to go around the head and then drape down to the torso.  That has lots of surface area, so the air draw wouldn't be hard.  But it would tend to be hot and stuffy. 

Add a filter to that with a fan drawing through that filter.

You might look like Buck Rogers....

There are also full face masks that were intended for snorkeling. There are designs for adding filters (N95, etc.), but these masks will be very hard to acquire.