1. Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia
2. Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
3. Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstraβe 8-10/134, 1040 Vienna, Austria