Multi-Target Dielectrophoretic Separation And Optimization In Gradually Expanded Sawtooth Channels

The particle manipulation technology which based on microfluidics and direct current insulator dielectrophoresis is non-invasive,non-destructive,inexpensive and high efficiency.In this paper,a two-dimensional numerical simulations has been conducted for the design of a gradually expanded sawtooth particle separator based on direct current insulator dielectrophoresis separation technology.Polystyrene particles with 5 diameters of 4μm、8μm、12μm、16μm、20μm,respectively,are separated simutaneously.The influences of electrophoretic force and dielectrophoretic force on the trace of particles are analyzed,and the separation distances are compared for both the designed micro-separator and its counterpart separator(i.e.,a parallel sawtooth particle separator).The results show that particles of different diameters are completely separated for retrieve in the designed separator,and the relative separation distances of the particles are larger in the gradually expanded sawtooth microchannel than that in the parallel sawtooth microchannel.This implies the designed separator has the ability of separating multitarget with higher throughput.Furthermore,the angle of the expansion for the separator,the voltage and sawtooth number are optimized for the designed separator to achieve multitarget separation and high throughput efficiency.Finally,the outlet is redesigned in order to make sorting and collecting particles with different diameter more convenient.And get following conclusions :Influenced by the dielectrophoretic force,the trajectory of particles will have a radial offset,and particles with different diameter have different offset;The dielectrophoretic force in gradually expanded sawtooth microchannel decreases rapidly,but the separate distance of particles becomes larger compared to that in the parallel sawtooth microchannel,this will help the collection of different particles;Increasing the expend angle in gradually expanded sawtooth microchannel will increase separation distance between different particles and width of particle flow;Respectively,the voltage and sawtooth number can be optimized,based on the data and fitting formula,the corresponding appropriate combination can be obtained for different particle separation needs.This investigation provides new design and theoretical supports for multitaget's high resolution and high throughput continuous separation.