1. Department of Polymer Engineering, National Taiwan University of Science and Technology, 43, Section 4, Keelung Road, Taipei, 106, Taiwan, Republic of China, Department of Biomechatronics Engineering, National Pingtung University of Science and Technology, PingTung, Taiwan, Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan, and Department of Materials and Optoelectronic Science, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan