Parylene is the trade name for a variety of chemical vapor deposited poly(p-xylylene) polymers used as moisture and dielectric barriers.

Parylene coatings are moisture and chemical barriers for medical device components. It peovides a pinhole-free barrier to protect against body fluid as well as moisture, chemicals and common gases.

It may be used for coronary stents, neurostimulation devices, cochlear and ocular implants, pacemakers.
It may serve as surface primer, such as on drug-eluting stents.

It protects medical electronic components from moisture, biofluids and biogases.