1. School of Materials Science and Engineering and Centre for Biomimetic Sensor Science; Nanyang Technological University; 50 Nanyang Drive 637553 Singapore
2. College of Business; Korea Advanced Institute of Science and Technology; 85 Hoegiro Seoul 130-722 Korea
3. School of Chemical and Biomedical Engineering; Nanyang Technological University; 62 Nanyang Drive 637459 Singapore