What does a sliding triboelectrical sensor really measure?

Abstract

For a decade, Triboelectric Nanogenerators (TENG) have been massively developed and optimized either as (i) triboelectric energy harvesters or, (ii) triboelectric self-powered sensors. Unfortunately, it is obvious that the classical tribologists’ concerns – like the optimization of both real contact area, friction laws and wear processes – have never really been integrated so far neither in their development processes nor in their triboelectrical responses. Thus, a question as basic as “What kind of tribological information can we expect from multi-asperity triboelectric sensor rubbing on a plane in dry friction?” does currently not lead to a trivial answer.This paper tries to get out this paradoxical situation by simulating triboelectrical behavior of a multi-asperity real contact area in dry friction. Results reveal that a sliding triboelectric sensor assesses the instantaneous and averaged velocities of every interacting asperities within the contact area, finally probing, in real time, the tribological actual contact area behavior during sliding.