[McBeige]

Inflating is such a cool idea, it'd work for any 3D shape I can think of.

If keeping air pressure is an issue, that might be resolved by making the sheet rigid once deployed. Are there UV curing resins that won't cure at all before being exposed to UV?

Speaking of sunlight, heating from the sun could be used to create the pressure for inflation. Or off-gassing from UV induced reactions.

[londons_explore]

Most plastics slightly 'cure' in UV anyway, in that they lose their plasticity and become more rigid.