Hey Rich
Take a better look at the article. The membrane is multi-layered, and is 30nm (which I'm reading as nanometers) thick. That's what, about a third of a micron? While that is incredibly thin, it's definitely over a molecule. So more than likely a larger panel is possible.
So they sound better than a 15 buck earbud! They didn't set the goal too high, did they?
Yes, this does fall into the "it's a miracle that it works" category, and I'm not trying to denigrate the accomplishment, let's see how it shakes out.
Silicon and SiO2 are standard semiconductor materials - the base of almost all ICs. Using it for small stators is interesting.