Study of dielectric properties of leukocytes for the determination of malignancy by capacitive type MEMS sensor

The present work deals with a non-clinical scheme to develop a system-on-chip for the detection and identification of the malignant cells in a known volume of white blood cells (WBC) using MEMS capacitive sensor. In presence of cancerous cells, the sensor produces a change in the value of capacitance which reflects a significant variation of dielectric permittivity. For this purpose, a double shell electrical model of WBC is designed and analyzed in frequency range 20 kHz–10 MHz due to the polarization of cell membrane. The polarization is induced using electroporation process where the plasma membrane of the blood cell is polarized to a membrane potential of about 0.5–1 V with a supply of 1 V which makes cell membrane semi permeable for the exchange of ions, thus producing change in dielectric permittivity. In order to determine the change in dielectric permittivity, an electrostatic MEMS capacitive sensor is virtually fabricated with a pair of rectangular electrodes in which the second electrode is further divided into four sub-plates in same plane. This change in permittivity results in change of output capacitance, finally differentiate a malignant cell from a normal one.