This, on the other hand (see immediately below), looks like it might have its uses.
When I was a kid I used to have a lot of fun throwing rulers through the air, while imparting a massive amount of under spin, like one of those hovering slices you do in ping pong, releasing the ruler sideways on. Hope that makes sense. The result was a whirring tube of physics activity that used almost to hover motionless. I’m guessing that the FanWing concept makes use of the same principle, and gets it seriously organised. The principle seems to be that, since an aircraft gets its lift from air passing fast over its wings, the more “wing” you can contrive to get air passing fast over, and the faster it can pass (even if the aircraft itself is moving very slowly, like my rulers), the more lift you get.
On the other hand, they’ve been messing around with this thing for over a decade, and it still seems like little more than a toy.
But then again, I presume it took them quite a while to get those other contraptions based on similar principles, helicopters, working usefully.