First: FormLabs, you guys should really add a COVID-19 category for you forum so that people can properly post ideas / projects / and progress.
N95 Mask Idea
I have done some reading, on form labs, CDC, and FDA white papers regarding additive manufacturing of medical devices. Focusing on the N95 masks. From what I have read, formlabs machines are not capable of printing filters. The layer resolution cannot get small enough to ensure that they function properly. There is also an issue in general with 3D printing masks out of hard plastic, because it is very hard to get a good seal. By no means am I a doctor, or educated in any form of medical type engineering. So please take the following with that in mind.
The filter problem
As stated above FormLabs machines cannot print fine enough to create filters. But they should be able to make everything else for these masks. If we can take current N95 rated masks and cut them up to be used as filters in the 3d printed masks. Takeing one mask (like the one shown here) and possibly turning it into 5-6 masks. By cutting the masks into disks to be placed into a re-usable/sanitize-able 3D printed filter.
The fit and seal problem
FormLabs has a wide variety of engineering materials. Some are not rigid plastic. Printing the bulk of the face covering in flexible or elastic, a good seal should be able to be made. The mask should be designed so that the fastening mechanism to the wearers head is easily replaceable with varying sizes of strings. Maybe use a separate printed part for the back of the head that is adjustable like a hard hat? This still leaves the issue of extra particles making it through the mask that get through the layer resolution on the printer. Using a dip coating (of some kind) that would seal the mask portion entirely much like how a UV sealant is applied to prints currently. May make them usable.
Combining, the two concepts a reusable system may be 3D printable. These are just some thoughts I had on the problem. Please let me know what you think.