A Milli-Fluidic Device for Electrical Impedance Spectroscopy of Complex Liquids

Rapid characterization of complex liquids such as solutions, mixtures, dispersions, and emulsions is useful in a variety of industrial applications ranging from cosmetics, pharmaceuticals, to petroleum production. An electrical impedance spectroscopy (EIS) based technique for rapidly determining the characteristics of liquid-liquid mixtures is presented in this study. A milli-fluidic liquid film impedance measurement cell is developed employing 3D printing technology. The cell is tested using glycerol-water mixtures followed by castor oil in water emulsion samples. Frequency response analysis and equivalent circuit modeling are performed on each sample to quantify the emulsion properties in the form of equivalent capacitance and resistance. The developed technique provides an inexpensive and disposable, yet robust experimental platform for applying EIS to investigation and rapid estimation of different properties of oil-water emulsions.