Thanks, but the video doesn't actually explain it. It explains a lot around it, but it just says that the chip uses a "piezoelectric fan" and shows the intake slits and the outtake jets, but I'm still not finding an explanation of the mechanism itself.

I can vaguely imagine how valves might work, but I'm still curious how they do. I looked at the linked patent applications but the descriptions seem way too complex and abstract to get any kind of intuitive sense of the mechanism without already being an expert.

There's a related video they link to: https://youtu.be/NY-gA_zA_os?si=9ULOds_TqUO56MGs which demonstrates one type of piezoelectric fan, but it seems to be operating on totally different principles -- one end is freely swinging, rather than a membrane with fixed edges oscillating. And there are definitely no valves involved in that one.

Is there anywhere else that explains how oscillating membranes generate smooth airflow?