About the Authors

Jianing Wu

Affiliation Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, P. R. China

Shaoze Yan

yansz@mail.tsinghua.edu.cn

Affiliation Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, P. R. China

Jieliang Zhao

Affiliation Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, P. R. China

Yuying Ye

Affiliation Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, P. R. China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: JW SY JZ YY. Performed the experiments: JW SY JZ YY. Analyzed the data: JW JZ YY. Contributed reagents/materials/analysis tools: JW SY JZ YY. Contributed to the writing of the manuscript: JW SY JZ YY.