1. Research Center for Intelligent and Wearable Technology, College of Textiles and Clothing, State Key Laboratory of Bio-Fibers and Eco-Textiles, Intelligent Wearable Engineering Research Center of Qingdao, Qingdao University, Qingdao, Shandong266071, P. R. China
2. College of Physics, Qingdao University, Qingdao, Shandong266071, P. R. China
3. College of Material Science and Engineering, Qingdao University, Qingdao, Shandong266071, P. R. China
4. Ocean University of China, Qingdao, Shandong266071, P. R. China
5. Materials Science & Engineering, Jiangsu University, Zhenjiang212013, China