Flexible Piezoelectric Crystals?

That is the best-known film, and reasonably cost-effective. Not all PVF film is piezoelectric, however. The film must be "poled". Oriented and poled film will give the highest piezo-electric effect, but is usually somewhat more rigid than unoriented poled film.

It will withstand reasonably high temperatures (I'm not sure where it depoles, however). But don''t overheat it, as the fumes are highly toxic (including HF).

Correct. PVDF has many uses aside from piezoelectric films.

The OP didn't share his intended use. He hasn't been back.

Cheers.

Probably 25 years I was playing with some stuff called Kynar film that was piezoelectric and also pyroelectric. It may be the same chemical as previous entry.