Switching Friction via Sliding Ferroelectricity.

Abstract

Reversible modulation of friction in atomically thin two-dimensional materials remains challenging in micro- and nanotribology, primarily due to the difficulty in achieving control over interfacial interactions. Harnessing switchable internal degrees of freedom provides a viable strategy for controlling interfacial energy dissipation. Here, ferroelectric polarization reversal induced by interlayer sliding in bilayer 3R-MoS₂ facilitates an electric-field controlled friction switch. Under a positive bias, polarization reversal (downward) reconstructs interfacial electronic states, weakening electrostatic interactions and phonon dissipation, switching the system into a low dissipation friction state with an ultralow coefficient of friction (0.0084). In contrast, under a negative bias, stabilized upward polarization enhances electrostatic interactions and establishing efficient phonon dissipation channel, switching into a high dissipation state. The friction state is electrically erasable and rewritable, with repeated writing cycles stabilizing the polarization configuration and enhancing switching robustness, thereby enabling reconfigurable friction control and interfacial energy management.