1. Department of Electrical & Computer Engineering; National University of Singapore; 4 Engineering Drive 3 117576 Singapore
2. Singapore Institute for Neurotechnology (SiNAPSE); National University of Singapore; 28 Medical Drive, #05-COR 117456 Singapore
3. Center for Intelligent Sensors and MEMS; National University of Singapore; 4 Engineering Drive 3 117576 Singapore
4. Department of Biomedical Engineering; School of Medicine; Johns Hopkins University Baltimore; MD 21205 USA