Abstract
As the development of the modern molecular biology, drug screening, and diagnosis, modern biotechnology requires the isolation and analysis of a single cell. In the past, handling a single cell was a hard process of dilution. The approach is disadvantageous especially for rare cells. Microdevices designed by dielectrophoresis can not only reduce sample volume but also trap the designated cell more efficiently. On the research, I constructed a three dimension (3D) microelectrode systems embedded in a 30μm resist, SU-8, forming a flow channel. The microelectrodes include symmetric and asymmetric elements driven by alternating current (AC) signal. The symmetric and asymmetric elements are designed to concentrating, deflecting, turning, and trapping polystyrene (PS) beads and human umbilical vein endothelial cell (HUVEC) and human embryonic lung cell(HEL 299). The concentration electrodes operated at 10Vp-p and 1MHz，and 6μm and 10μm polystyrene beads can be concentrated at the flow velocity 800μm/s and 1,400μm/s, respectively. Deflection and Turning Electrodes can provide function of switch and separation of polystyrene beads. Polystyrene beads was separated when they passed the turning region, and we employ a numerical analysis method combined with electrical field and flow field simulation data to predict the route of beads of different size. On this research experimental devices can trap a single polystyrene bead, human umbilical vein endothelial cell, and human embryonic lung cell (HEL 299). Especially, it can trap 6μm polystyrene beads at 225μm/s flow velocity under 40μm inter-space of electrode, 10Vp-p, and 1MHz. We used charge-coupled device and Image-process software to calculate flow velocity and rotation frequency of particles.