A cellular preconcentrator utilizing dielectrophoresis generated by curvy electrodes in stepping electric fields

摘要

Concentrating rare cells, such as circulating tumor cells (CTC), circulating fetal cells, and stem cells, is an important technique in biological and clinical studies. The main purpose of the present study was to design a dielectrophoretic microdevice for achieving an effective preconcentration of cells. Interdigitated. curvy electrodes were designed to generate the stepping electric field by switching the electric field to an adjacent electrode pair via relays. The positive dielectrophoretic cells were not only conveyed in the direction of the stepping electric field but were also concentrated at the last pair of electrodes as the high-electric-field region between the adjacent electrodes was gradually decreased in the direction of the stepping electric field. Numerical simulations of the electric field and the particle trajectory were performed to demonstrate the concept of the proposed design. The overall circuit system generating the stepping electric field for cellular pre-concentration was constructed on a printed circuit board (PCB) and the microdevice was assembled with the PCB. The pre-concentration of HeLa cells, which are a human cervical carcinoma cell line, was successfully achieved and took about 340 s in the preliminary experiment when the peak-to-peak voltage of 10 V and a frequency of 1 MHz were applied.