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 non-uniform electric fields. The aim of this research is to make a correlation of capacitance change to the DEP response, which is determined by the CMf plot. Second, we aim to make a comparison of the capacitance change in biological molecules and engineered particles. Thirdly, the optimization of the ideal geometry of the integrated microelectrodes for the most optimal capacitance change value. The numerical simulations results reveal that both BSA and the polystyrene beads (PS) exhibit a crossover frequency (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">xo</sub>) 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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">xo</sub> for BSA and PS are determined to be 2.63 MHz and 411.98 kHz. 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. In conclusion, this study presents an investigation of the DEP based actuator response of BSA can be used for detection of various biomolecules.