1. Okanagan Microelectronics and Gigahertz Applications laboratory School of Engineering University of British Columbia Kelowna British Columbia V1V 1V7 Canada
2. State Key Laboratory of Advanced Forming Technology and Equipment Beijing National Innovation Institute of Lightweight Ltd. Beijing 100083 China
3. Centre of Materials Science and Engineering School of Mechanical and Electronic Control Engineering Beijing Jiaotong University Beijing 100044 China
4. Nanomaterials and Polymer Nanocomposites Laboratory School of Engineering University of British Columbia Kelowna British Columbia V1V 1V7 Canada