Microfluidic System With Integrated Electrode Array for Impedance Tomography of Cell Cultures

Electrical impedance tomography is originally a macroscopic screening method which applies electrochemical impedance spectroscopy (EIS) technique to provide insight into the inner regions of biological systems, tissues, and bodies. However, it only delivers macroscopic information regarding the examined volume, which lacks cellular information. With miniaturization, by creating a complex microfluidic system that incorporates an electrode array applicable for sensitive EIS measurements across the system, the desired cellular resolution could be achieved. This would contribute to in situ 3D monitoring of cellular proliferation, structural changes, and the effects of therapeutic treatments. In this work, a microelectrode array was integrated into a microfluidic chip, which can conduct location-dependent EIS measurements, providing high-resolution spatial information about the electric field in the channel. The device was already tested with physiological saline, PBS solution, HEPG2 cell culture medium, and yeast solutions. The demonstrated cell analytical systems are primarily applicable for monitoring biological processes modeled by cell lines in a microchemical environment by the combination with microscale impedance tomography methods.