Movie S3.
Graphite flake oscillates at a certain normal load. One flake of the mesa pressed by the probe’s tip (the dark part) is oscillating. Since the frame rate of this video is 10Hz, it looks like a low frequency vibration. The actual frequency calculations are given in SI appendix.
Load-induced dynamical transitions at graphene interfaces
PNAS. 2020. 117:12618-12623 DOI: 10.1073/pnas.1922681117