Integration of Dielectrophoresis Mechanisms With Capacitance Measurement for Bovine Serum Albumin (BSA) Manipulation

Dielectrophoresis (DEP) is a technique that leverages the dielectric properties of molecules for manipulation to study their behavior under the influence of nonuniform electric fields. The aim of this research is to make a correlation of capacitance change to the DEP response, which is determined by the Clausius-Mosotti factor (CMf) plot. Second, we aim to make a comparison of the capacitance change in biological molecules and engineered particles. Third, the optimization of the ideal geometry of the integrated microelectrodes for the most optimal capacitance change value. The numerical simulations results reveal that both bovine serum albumin (BSA) and the polystyrene (PS) beads exhibit a crossover frequency ( f_xo ) transitioning from positive-DEP (pDEP) to negative-DEP (nDEP). We conduct an experimental DEP-based actuator on both BSA and PS while measuring the capacitance of the DEP response. For further validation of the capacitance measurement, we conduct an experiment on different widths, d1= 16 μm, d2= 20.5 μm, and d3= 25 μm, of capacitance microelectrodes. Result has proved that the f_xo values for BSA and PS are determined to be 2.63 MHz and 411.98 kHz, respectively. The capacitance change variation value for BSA is determined to be higher than PS where the coefficient of variation (CV) value for BSA is 1.3814 and for PS is 0.8528. Result from the validation for different capacitance microelectrode widths shows that 25 μm has the most optimal mechanical geometry.