Excitation Friction-Reducing Method Considering Low Power Consumption and High Operational Stability

Abstract Applying mechanical vibration at resonance-frequency is widely recognized for achieving friction reduction, yet it often involves high vibration amplitudes that can cause tip wear and require substantial energy. This study reveals that a friction minimum also occurs at sliding velocity-dependent washboard-frequency under both in-plane and out-of-plane excitation. Compared with resonance-frequency excitation, washboard-frequency excitation exhibits higher stability. Both washboard- and resonance-frequency excitations can achieve over 80% friction reduction, while the energy input required for washboard-frequency excitation is only approximately 1.7% of that for near-resonance-frequency excitation. Friction reduction at washboard-frequency stems from excitation-induced changes in normal force and tip stick–slip dynamics. Concurrently, the friction reduction efficiency is strongly related to the excitation phase. Only when the instantaneous excitation perfectly matches the stick–slip motion can the most obvious friction reduction effect be achieved. Furthermore, we have also demonstrated that the technique of reducing friction, through excitation of washboard-frequency, can be employed to the sliding surface of the strain-induced moiré superlattice. This work provides insights for designing friction-reduction strategies that prioritize low power consumption and high operational stability.