Numerical study and statistical analysis of effective parameters on dielectrophoretic separation of particles using finite element and response surface methods

Size-based separation in microfluidic systems is a technique that allows the separation and sorting of particles or cells based on their size. In this work, we propose a microfluidic device that consists of cylindrical electrodes. The particle motion equation is solved by the finite element method in the presence of dielectrophoresis and thermal forces. In the present work, the effect of particle size, applied electric potential, electrode size, and electrode position on the dynamics of particle motion is investigated. Numerical results show that for the proposed microchannel, four particle separation regimes are observed. The influence of various parameters can lead to different regimes for particles separation. These regimes guide particles to different outlets or particles to be trapped. These regimes are influenced by controlling parameters such as particle size, applied electric potential, electrode size, and electrode position. The response surface method is applied to modeling and predicting the variation in responses. The results of response surface method indicate that the separation diagram of particles based on their size has a strong dependence on the electrode position. The response surface method has been shown to accurately predict variations in the critical size of particle. The results obtained from the response surface method indicate that average prediction error of critical radius of particle in the separation diagram is less than 8%.