Selective position of individual cells without lysis on a circular window array using dielectrophoresis in a microfluidic device

We trapped individual cells between two circular windows using negative dielectrophoretic (DEP) force and then sequentially trapped them inside circular windows by positive DEP force without electrical lysis in a microfluidic device. Three parameters, (1) the transmembrane potential that determines the lysis of a cell, (2) individual cell size that affects the trapped position accuracy of the cell, and (3) the Clausius–Mossotti (CM) factor that decides the trapped efficiency of the cell, were characterized experimentally and numerically in this sequential cell trapping technique. In this characterization, we confirmed that the swap rate of applied voltage frequency, size similarity between the cell and circular window, and instantaneous change rate of Re(f_CM) as a function of frequency were important factors in determining the selective position of individual cells without lysis. Our results provide useful suggestions for designing the structure of microfluidic DEP devices and optimizing variables required to manipulate individual cell trapping using both negative and positive DEP forces.