Plasma polymerization, electrically active

When an organic vapor, such as methane, in low pressure (e.g., less than 1 torr) is subjected to an electromagnetic field, the electrical breakdown of the gas occurs, yielding a glow the color of which is characteristic to the gas. In the luminous gas phase, methane is activated and forms a polymeric deposition in the form of a coating on the surface of substrate placed in the glow. This process is termed plasma polymerization because the luminous gas phase or glow indicates the presence of plasma, and the process does not proceed without plasma. The strict definition of plasma is (at least partially) ionized gas, which maintains the electrical neutrality as a whole. The luminous gas phase in which plasma polymerization takes place, however, is not plasma in the strict sense. 

Research and development of plasma-polymerized organic thin films have been imder-taken very actively in the last years and some of the products have been applied in a variety of technologies such as optical, biomedical, electrical, and chemical industries. 

Intermediate layers appear to be necessary for good adhesion in corrosive and other chemically active environments. Their role is to suitress diffusion of destmctive agents towards foe interface. In this cr acity, plasma polymerized hydrocarbon (CH4) Elms have been found to improve bonding of Pt electrical contacts to parterre or other polymers, used as implantable, biocompatible sensors [56]. 

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