High-performance efficient embedded systems for impedance spectroscopy: Challenges and potentials

Abstract

Impedance spectroscopy is nowadays in use in a wide range of applications where there is a particular need for efficient embedded measurement systems. Several embedded impedance spectrometers based on Field Programmable Gate Array (FPGA) have been proposed but have several drawbacks, notably high power consumption, high cost, and complex development frameworks. Meanwhile, microcontrollers have become more powerful, enabling the efficient design of embedded impedance spectrometers. A major challenge, however, is to achieve high measurement performance in terms of accuracy while complying with the conditions for impedance spectroscopy. This paper addresses the potential of microcontroller-based system design for embedded impedance spectrometers and proposes a methodology to comprehensively design compact and efficient microcontroller-based impedance measurement systems. After a review of possible measurement methods, we focus on the optimization of multi-sine excitation signals,the acquisition of current and voltage signals, and the efficient signal analysis, which are key elements in realizing embedded impedance measurement systems that achieve high quality measurements while maintaining linearity and system stability conditions. We demonstrate the efficiency of the proposed design methodology in the two application scenarios of battery diagnosis and bioimpedance spectroscopy.