Insulator-Based Dielectrophoresis: Effect of Insulating Structure Geometry

Lab on a Chip devices are becoming increasingly important for many bio-analytical applications. There is growing interest in the development of analytical and separation techniques that can be applied at the microscale level. Dielectrophoresis (DEP) is becoming one of the leading techniques in this regard. DEP is defined as the movement of particles in solution caused by polarization effects when the particles are exposed to a non-uniform electric field. Insulator-based dielectrophoresis (iDEP) employs arrays of insulating structures to manipulate the electric field thus resulting in altered mobility of microparticles through the system.  The use of dielectrophoresis in microfluidic devices as a separation or concentration method for particles or cells is becoming an important option for many different applications where short analysis time and quick results are required, such as food safety, environmental monitoring, and clinical analysis.  The use of computer modeling is a powerful tool for designing microdevices for dielectrophoresis. Modeling can effectively determine the distribution of the electric field and map the regions of relatively higher electric field due to different geometries of insulating structures used in iDEP. By employing mathematical modeling with COMSOL, the behavior of the electric field can be predicted for different arrays of insulating structures. With this information, ideal geometries can be selected in order to improve particle trapping with iDEP, increase efficiency, and reduce energy consumption. This study includes an investigation on the effects of insulating structures’ geometry on the efficiency of iDEP microdevices for microparticle manipulation and trapping.