Fig. 1. Tuning friction force and reducing wear via applying alternating electric current in conductive AFM experiments.

a The c-AFM experimental setups and current density calculated by DFT + NEGF of Ir/Gr/Ni interface. b The averaged friction force of the scan region under 1 V alternating voltage with different frequencies, under 2.4 nm s⁻¹ sliding velocity. Error bars indicate the standard deviation of the friction force obtained from 1024 friction loops. c, d The lateral force maps and friction loops (along the black dashed lines) measured before (c) and after applying 1 V / 1 kHz alternating voltage (d). eThe friction force evolution of Ir/Gr/Ni interface under 1 V amplitude and 1 kHz frequency alternating voltage (red line) and no bias voltage (blue line). f The lateral force maps measured before (①③) and after 20 h friction (②④) under 840 nN normal load with (③④) and without (①②) alternating current. The SEM images of the AFM tips observed before (①③) and after (②④) 20 h friction under 840 nN normal load with (③④) and without (①②) alternating current. Source data are provided as a Source Data file.