Controllably moving individual living cell in an array by modulating signal phase difference based on dielectrophoresis

This paper reports a novel dielectrophoresis (DEP) based method for manipulating individual living cells by modulating phase difference of electrical signals applied on DEP electrodes. A novel microchip with an array structure is also proposed, consisting of a plurality of quadrupole-electrode units patterned into array on a glass substrate with a pair of center electrodes locating at the center of each quadrupole-electrode unit. Living cells can be trapped and positioned at the center of each quadrupole-electrode unit by using negative DEP (nDEP) manipulation and form an array. The trapped cells in the array can be controllably moved from one position to another and even from one of quadrupole-electrode units to adjacent unit by changing the phase difference of the signals applied on the two pairs of opposite electrodes in each quadrupole-electrode unit. The microchip allows an efficient and flexible manipulation of individual living cells that can be applied to study single cells. The experiments are performed to verify that different types of cells (MCF-7 cell and HeLa cell) can be effectively distinguished between each other using the method without label and fluorometric measurements. An identification of individual living cell from dead cells is also well demonstrated.