Would this work:
Take a lawnmower, mount a plate (steel, plywood, etc) under the entire deck, effectively creating a sealed cavity inside which turns the mower blade. Seal around the edge where the deck meets this plate.
Cut a slot across the center of this plate, from left to right. Maybe an inch wide.
Take a brisle broom that's as wide as the mower, and mount it to the underside of the plate, just in front of the slot. A broom with short bristles - say, 1" long. Possibly add second broom on the back side of the slot - or a rubber flap in contact with the ground to act as a seal to help concentrate the vacuum effect.
Take the mower blade and give it more of a twist - make it look more like a fan blade.
Adjust the deck height so the broom is in good contact with the ground, but you can still push the mower reasonably well across the ground (or pavement).
Main purpose: Clean pavement and nearby grass of small sand/gravel put down over the winter to combat snow and ice.
Secondary purpose: Pick up debris on grass left behind after a brutal winter. This includes a ton of sunflow shells, bird seed, other "grunge".
A lawn mower aught to be able to generate quite a vacuum given a properly-constructed housing.
Would this work as imagined?
PS: Lowering the mower so that the deck skids across the pavent does pick up road sand, but it's very messy, throws a lot of it back at the operator, must wear face shield and long pants, etc.
I've not seen anything like this on youtube.