(516b) Obstacle-Density Effects on Particle Trapping in Insulator-Based Dielectrophoresis Systems

In insulator-based dielectrophoretic (iDEP) devices, insulating structures are placed between electrodes to produce non-uniformities in the electric field. This creates polarization effects on particles and allows for their manipulation when the dielectrophoretic force induced overcomes all other forces in the system. Microchannel designs usually include an array of insulators, i.e. posts, and particle trapping sites are generated within the post-array. An increase in the number of posts enlarges the number of potential trapping zones where particles can be immobilized. This study presents the effect that the number of columns of insulating structures have on the gradient of the electric field squared in an iDEP microdevice. A mathematical model was created in COMSOL Multiphysics and later validated by experimentation, where it is shown that the column density (number of columns/unit length) has an effect on the magnitude of the dielectrophoretic force produced when an electric field is generated in a microdevice.