부산대학교 도서관

Electrochemical Impedance Spectroscopy (EIS) is a non-invasive method to evaluate biological samples. With the use of EIS results, the transepithelial electrical resistance (TEER) can be measured to estimate the condition of e.g. in-vitro lung epithelia under various diseases. In this regard, many epithelial samples must be prepared, which is a time consuming task. Parallel measurements with the use of multi-electrode arrays (MEA) increase the throughput of the system. Careful electronic design must be considered to guarantee safe and fast MEA-EIS measurements. Available MEA-EIS systems are mostly limited by either limited frequency and dynamic range or long measurement time. Particularly slow MEA-EIS measurements are disadvantageous for epithelial cells since during the EIS measurements they are kept in a harmful environment. In this work, a fast MEA-EIS system for 24 channels is presented. The designed MEA-EIS system takes less than 20 seconds excitation time for a frequency range of 1 Hz to 100 kHz with the use of parallel recording and multi-tone excitation signals. The proposed system is realized using discrete components on a PCB and its functionality with the designed MEA is successfully verified using biological samples. A matching better than 95% between the extracted TEER values from the designed system and commercially available devices is observed. MEA-EIS measurements are performed in a frequency range from 10 mHz to 100 kHz with minimum and maximum detectable impedances of $6~\Omega $ and 300 $\text{k}\Omega $ , respectively.