1. Nanotechnology and Catalysis Research Centre (NANOCAT), IPS Building, University of Malaya, 50603 Kuala Lumpur, Malaysia
2. Department of Biomedical Engineering, Faculty of Engineering, University Malaya, Kuala Lumpur, Malaysia
3. Department of Mechanical Engineering, Faculty of Engineering, University Malaya, Kuala Lumpur, Malaysia
4. Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA