Analysis of Microelectrode Arrays for Dielectrophoresis using the Finite Element Method

摘要

Dielectrophoresis (DEP) is a widely used separation technique for polar or polarizable particles based on the movement of the sample species which occurs when the particles are subjected to a non-uniform electric field [1]. The work presented is focused on the analysis of the DEP force distribution at nanoscale heights above the electrodes dependence on microelectrode size parameters. Results of the investigation may already find application in the fabrication of microfluidic lab on chip devices to separate or control motion of the particles in nanometer scale microfluidic channels [2]. DEP force theoretical analysis was performed using the finite element method and the dependence on microelectrode width, spacing and thickness was acquired. The electrode structure modelled was the interdigitated golden electrodes with thin Cr ahesion layer on glass substrate. Research results are applicable for any microelectrode structure that inherits rectangular structure of single microelectrode finger in its design. Using numerical calculations the influence on the gradient of electric field of each microelectrode's size parameter when the other two size parameters are altered was investigated. Taking into account resultant data, respective microelectrode structure design adjustments for future fabrication were discussed. DEP force dependence on electrode size parameters plots and research conclusions are also presented in this work.