Design of a Multi-Channel Impedance Acquisition and High-Throughput Imaging System for Biological Characterization

Abstract

Impedance measurement is an established method for characterizing biological processes such as cell growth and cytotoxicity, but current acquisition methods are limited by instrumentation and specificity. This thesis addresses these limitations by introducing a multi-channel impedance acquisition system alongside an automated imaging platform. The impedance system multiplexes the output of a lock-in amplifier to the selected electrode and measures the resulting current to compute impedance. The automated imaging system uses a motorized XYZ-stage with a camera to capture time-lapse images across multiple samples. Baseline testing demonstrated that the multiplexer system could measure resistances with high accuracy (1-2% error), although multi-well plate experiments exhibited both consistent and drifting electrode measurements. Imaging experiments showed the stage could operate long-term while maintaining its position with minimal drift. Together, these systems provide both electrical and structural data, addressing the limitations of impedance measurements in isolation. This platform also provides a foundation for future closed-loop systems that integrate real-time sensing, imaging, and stimulation.