集成惯性聚焦结构的介电泳微流控芯片的粒子连续分离

A dielectrophoresis microfluidic chip with inertial focusing structure was designed and fabricated to realize the continuous separation of particles with different dielectric properties. The dielectrophoresis microfluidic chip was fabricated by MEMS: a pair of trapezoidal structures is provided at the inlet side walls of the channels to allow the passing particles to be focused by inertial lift forces on either side of the channel. At the bottom of the channel, a set of tilted interdigitated electrodes with an included angle of 90 ° were etched to produce a non-uniform electric field. By using the force of the dielectrophoretic force and the fluid drag force, the different particles on both sides of the channel are deflected into different channels at different angles so as to realize the separation. Saccharomyces cells and polystyrene beads were used as experimental samples. The effects of flow rate and AC voltage on the separation were analyzed. The optimal conditions for the separation of the two were determined and the separation was carried out. Experimental results show that the yeast cell is discharged along the channel center at the angle between the electrode and the electrode. Polystyrene beads are discharged along the side of the channel. A sample solution with a conductivity of 20 μS/cm was injected into the channel at a flow rate of 5 μL/min. Applying 6 V_p-p, 10 kHz sine signal. The average separation efficiency reached 92.8% and the purity reached 90.7%.