A Quantitative Model of Triboelectric Charge Transfer

TL;DR

This paper develops a comprehensive quantitative model for triboelectric charge transfer, incorporating effects from depletion zones and flexoelectric polarization, aligning with experimental observations across different materials.

Contribution

It introduces a novel model that quantitatively describes triboelectric charge transfer, considering depletion and flexoelectric effects, advancing understanding of triboelectric phenomena.

Findings

Model predicts charge transfer scaling with contact parameters

Depletion and flexoelectric effects influence charge transfer

Results align with multiple experimental trends

Abstract

Triboelectricity, when rubbing or contacting materials causes electric charge transfer, is ubiquitous across many fields, and has been studied in detail for centuries. Despite this, a complete description of triboelectricity remains elusive. Here, we analyze the contact between a metal asperity and a semiconductor, including contributions from the depletion zone of the semiconductor and from flexoelectric polarization that arises due to the strain gradients at asperity contacts. The free charges involved in charge transfer are then discussed and calculated. As a result, we develop a quantitative model for triboelectric charge transfer that details how charge transfer scales with contact parameters, the relative influence of depletion and flexoelectricity, and which agrees with various trends in multiple classes of triboelectric experiments.