Hybrid Multiband Sensor for Dielectric Spectroscopy in Microfluidic Applications

This article introduces a two-port microwave sensor designed for dielectric spectroscopy in microfluidic applications. The sensor integrates resonant elements within a microstrip transmission line to facilitate multiband analysis. It features distinct resonance frequencies at 7.8 and 15.6 GHz along with capabilities for low-frequency measurements showcasing versatility across a broad frequency range. Through electromagnetic simulations and experimental validations, the sensor’s performance is evaluated across various permittivity values using water-ethanol mixtures as test fluids. Key metrics such as relative error, coefficient of determination, and sensitivity analysis underscore the sensor’s efficacy. Additionally, Debye parameters were extracted from the measured data, offering insight into the dispersive behavior of the fluids across a broad frequency spectrum. This highlights the sensor’s potential for precise dielectric spectroscopy in biomedical diagnostics and material characterization.