It looks like the folks at U.S. Army Research Laboratory at Aberdeen Proving Ground have come up with concepts for inflatable structures for UAVs.
The folks at the lab believe that the use of inflatable structures would allow for lighter weight, which translates into slower flight speeds and less noise, both of which are optimal for the use of UAVs in an urban scenario.
Goodyear did actually develop and fly an inflatable aircraft, the Inflatoplane, in the 1950s, but the army decided it was too vulnerable to ground fire, and shelved the project.
Still, it has always surprised me that someone in the ultralight community did not go further forward with this. An ultralight made using this technology could fit in the trunk of a midsized car.
About a decade ago, I put an inqwuiry into Goodyear regarding the Airmat, basically balloon material with threads running between opposite walls to provide rigidity when inflated, material they used for the structure, but there was nothing left there.