Polymer materials are ubiquitous in medical devices, automobiles, electronics, food packaging and in a wide range of other industrial and consumer products. The surfaces of these materials can be modified to harden the surface, reduce or increase the surface reactivity and alter the surface roughness, etc. 

A common surface modification method involves using plasma to etch the surface or to introduce custom functionality to the surface. The modification may be performed for many reasons but it typically needs to impart a specific functional group and be free from contamination. The surface of the sample is altered when a plasma creates energetic species that react with the polymer surface to produce volatile compounds, thereby removing and/or adding molecules to/from the surface. 

The use of different types of plasma such as oxygen- or fluorine-based plasmas can generate new chemical species on the surface of the polymer and hence change its surface properties.