There exists a widespread assumption that electron transfer may constitute the principal mechanism of contact electrification in polymer based triboelectric nanogenerators. However, despite theoretical and experimental hypotheses that propose primarily electron cloud overlap and emission based interpretations, respectively, there is a consistent lack of conclusive arguments that would take into account the intrinsic dielectric properties of polymeric materials. To this end, there was performed a combined computational-experimental study of critical components that may have been neglected or overlooked by previous studies.

First, a comparison of the energy that is required for the creation of sufficiently close contact between polymer chains representing contacting surfaces and the energy that is required for the heterolytic dissociation of constrained polymer chains was performed. The comparison reveals that material transfer based charge transfer processes are significantly more likely due to reaction energy considerations. Further, according to negligible estimates of electron transfer rates of polymer/polymer and polymer/metal equilibrium contacts, contributions with respect to material transfer based rates could be ascertained as predominant below contact pressure levels that involve significant degradation of contact surfaces by wear. The theoretical conclusions were supported by experiments ranging from identification of strong dependence of polymer CE on their phase, adhesive and cohesive properties up to the observation of permanent charges on metallic surfaces after contact electrification with a polymer.