Design of Multidomain Interdigital Electrodes for Evaluating Anisotropic Analytes: Achieving Position-Independent Rotationally Symmetric Sensing Fields

This letter presents an enhanced design of interdigital electrodes that utilize fractal topology to achieve multidomain configurations, specifically incorporating a 12-fold pattern. The primary objective of this design is to generate rotationally symmetric electromagnetic fields at any sensing position. This characteristic effectively mitigates variations in sensing signals caused by random orientations of anisotropic analytes, such as long-chain polymers or proteins, particularly in scenarios involving low-concentration conditions or miniaturized device designs. Consequently, the proposed sensor not only offers the heightened sensitivity typically associated with conventional interdigital electrodes but also demonstrates the ability to avoid misjudgment of sensing signals influenced by the anisotropy and concentrations of the analyte simultaneously. To comprehensively evaluate the performance of the proposed sensor, a rigorous numerical analysis is conducted, comparing it with traditional interdigital structures. The results indicate that the proposed sensor outperforms its counterparts in terms of the limit of detection, electromagnetic compatibility, and measurement reproducibility. In addition, this research provides the MATLAB codes employed for generating the multidomain interdigital electrodes.