1 Advisor : Cheng-Hsin Chuang Advisee : Jing-wei Ju Department of Mechanical Engineering & Institute of Nanotechnology, Southern Taiwan University, Tainan, TAIWAN Date 2013/05/01 Outline Motivation Theory of Dielectrophoresis Simulation of a Non-uniform Electric Field Materials Preparation of nanoprobes Fabrication of the DEP Chip Experiment Setup Procedure Experimental Result Conclusions 2 Motivation Many studies utilized micro- and nano-beads for the sensitivity enhancement of biomedical detection due to the large surface- volume ratio. For the diagnosis of cancer, protein analysis is most important. Protein Testing Strips Expensive Time-consuming Only one kind of antibody How to do low-cost and fast detection of multi-antibody on a chip? Multi-antibody array chip Theory of Dielectrophoresis Dielectrophoresis- Motion of a particle produced by the interaction of a Non-uniform electric field with the induced effective dipole moment of the particle. Negative dielectrophoresis Positive dielectrophoresis +V -V Neutral bead Net Force Clausius-Mossotti factor Re(f CM )>0 ; Positive DEP Re(f CM )