The adhesion of glow--discharge polymers, Silastic and Parylene to implantable platinum electrodes: results of tensile pull tests after exposure to isotonic sodium chloride.

Thin organic coatings commonly are used for insulating microelectrodes and electronic packages designed for implant applications. The adherence of these coatings to the underlying substrates is a key parameter in their selection for various devices. Instron pull tests were performed on glow-discharge polymerized monomers, Parylene-N, medical-grade Silastic and various epoxies. The application of a thin coating of glow-discharge polymerized methane under a thicker Parylene-N coating improved the adhesion of the latter to the underlying substrate in isotonic sodium chloride solution and during accelerated testing conditions done by boiling.