The design is mostly straight forward. It will be a TPU based filament that holds the ULPA filter compressed in place. The fan will optionally be centrifugal (default) or axial. Additional prefilters will be optional.
https://www.thingiverse.com/thing:3454725 is the original design in Fusion 360. Several models will be redesigned for fit and new performance in OpenSCAD.
Based on the M12 lithion battery pack and USB-C powerbank.