When Flexoelectricity Drives Triboelectricity.

Abstract

Triboelectricity has been known since antiquity, but the fundamental science underlying this phenomenon lacks consensus. We present a flexoelectric model for triboelectricity where contact deformation induced band bending at the nanoscale is the driving force for charge transfer. This framework is combined with first-principles and finite element calculations to explore charge transfer implications for different contact geometry and materials combinations. We demonstrate that our <i>ab initio</i> based formulation is compatible with existing empirical models and experimental observations including charge transfer between similar materials and size/pressure dependencies associated with triboelectricity.