Electrical Impedance Spectroscopy (EIS) is a popular method for investigating tissue properties. Implementing the signal generator for EIS measurements with a suitable excitation signal type is thereby one of the two system components. The choice of the excitation signal defines the measurement speed, signal-to-noise ratio (SNR), total area and power consumption of the system, and many more properties. Signal types such as analog single-tone, analog multi-tone, linear feedback shift registers (LFSR), and single-tone Sigma Delta Modulated (Σ∆M) are proposed in the state of the art. In this work an EIS setup is implemented and successfully tested with all the mentioned signal types to evaluate their properties on impedance models as well as in vitro cell layers. It is proposed to combine the Σ∆M with the multi-tone excitation signal yielding a very versatile excitation generator. Multi-tone Σ∆M are as fast as analog multitones, while benefiting from a binary output and thus less system complexity. The implemented EIS setup is used to perform EIS measurement for biological samples. The results show a very good matching with the reference for all the excitation signals.

Electrochemical Impedance Spectroscopy (EIS) is a standard method to investigate properties of biological samples due to its non-invasiveness. Multi-electrode arrays (MEA) perform parallel measurements, which lead to higher throughput and thus reduced measurement time. However, implementing a parallel MEA EIS needs considerations to achieve safe and fast measurements. Commercially available devices perform single EIS and then serially scan the MEA. Their limited frequency range and limited detection impedance can be further increased to support more application. This work presents a 24 channel MEA EIS system that has highly reduced measurement time in comparison to commercially available solutions by utilizing multitone excitation signals. The EIS system has been implemented on a two layer PCB and successfully tested with biological samples. It consumes 17.5 × 17.5 cm 2 and draws 300 mA from a 5 V supply voltage. The EIS measurement frequency range spans from 10 mHz to 100 kHz and can detect impedances from 6 Ω to 300 kΩ. The prototype measurements have been compared with the commercially available devices and showed matching better than 95%.