On the role of flexoelectricity in triboelectricity for randomly rough surfaces

TL;DR

This paper explores how flexoelectricity causes fluctuating surface potentials in rough elastic solids under contact, potentially contributing to triboelectric effects, supported by theoretical analysis and experimental data interpretation.

Contribution

It introduces a theory linking flexoelectricity to triboelectricity in rough surfaces and analyzes existing microscopy data to support this connection.

Findings

Flexoelectricity induces fluctuating surface potentials in rough elastic contacts.

Flexoelectric effects can contribute to triboelectric charge generation.

Analysis of microscopy data supports the theory's relevance.

Abstract

I show how flexoelectricity result in a fluctuating surface electric potential when elastic solids with random roughness are squeezed into contact. The flexoelectric potential may induce surface charge distributions and hence contribute to triboelectricity. Using the developed theory I analyze the Kelvin Force Microscopy data of Baytekin et al for the electric potential above a polydimethylsiloxane (PDMS) surface after it was peeled away from another PDMS surface