ENGINEERING Correction for “Tuning friction to a superlubric state via in-plane straining,” by Shuai Zhang, Yuan Hou, Suzhi Li, Luqi Liu, Zhong Zhang, Xi-Qiao Feng, and Qunyang Li, which was first published October 28, 2019; 10.1073/pnas.1907947116 (Proc. Natl. Acad. Sci. U.S.A. 116, 24452–24456).
The authors wish to note the following: “We have found that the Raman spectra curves obtained from another set of samples with similar strain states were incorrectly presented in the original Fig. S3 and Fig. S12. We have corrected the Raman spectra curves in the SI Appendix. Consequently, the strain values in Fig. 4 calculated from the Raman spectra curves in the original Fig. S12 were incorrect. The correct strain values are shown in the corrected Fig. 4. The error and the corrected results do not affect any of the other results nor alter the original conclusion.” The corrected Fig. 4 and its legend appear below. The SI Appendix has been corrected online.
Fig. 4.
Friction modulation with cyclic strains. (A) Friction versus normal force data measured on the suspended graphene with cyclic strains. Error bar represents the SD of the repeated measurements under the same normal load. (B) COF and the strain values of graphene during cyclic loading. The coefficient of friction were calculated by performing a linear fit of the mean friction vs. normal force curves in A.