1. Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
2. School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham, West Midlands, B15 2TT, United Kingdom
3. Center for Photonic Technologies, Universiti Tenaga Nasional, Bandar Baru Bangi, Selangor 43650, Malaysia