About the Authors

Hongyan Yuan

Affiliation Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania, United States of America

Changjin Huang

Affiliation Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania, United States of America

Sulin Zhang

suz10@psu.edu

Affiliation Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: SZ. Performed the experiments: HY CH SZ. Analyzed the data: HY CH SZ. Wrote the paper: HY CH SZ.