Beijing Institute of Nanoenergy and Nanosystems;
Chinese Academy of Sciences;
Beijing 100083;
China;
Collge of Nanoscience and Technolog;
University of Chinese Academy of Sciences;
Bejing 100049;
China;
School of Materials Science and Engineering;
Georgia Institute of Techmolog;
Atlanta;
GA 30332;
USA;
contact electrification; self-powered system; energy harvesting; triboelectric nanogenerator;