Finite-element modelling of triboelectric nanogenerators accounting for surface roughness

Triboelectric nanogenerators (TENG) transform mechanical energy into electrical energy as a result of contact between suitably chosen surfaces. Surface roughness plays a key role in the performance of contactseparation TENG, defining the ratio of real contact area to the apparent one for a given contact force. We develop a novel numerical approach for coupling mechanical contact and electrostatics equations to simulate TENG behaviour using the finite-element library MoFEM. Good qualitative agreement is found between the numerical predictions of the proposed method, available experimental data and approximate analytical models. The developed finite-element framework can be used for further study of the effect of various TENG parameters on the output performance.