1. State Key Laboratory of Mechanical System and Vibration, Interdisciplinary Research Centre, and MOE Key Laboratory for Power Machinery and Engineering, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
2. Materials Research Institute and Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
3. Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
4. School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA 16802, USA.