On the role of flexoelectricity in triboelectricity for randomly rough surfaces

I show how flexoelectricity results 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.