Microwave resonant sensor integration with impedance cytometry in microfluidic platform for probing micro-scale dielectric permittivity

This thesis presents a novel multiphysical sensor that integrates low-frequency impedance cytometry with high-frequency microwave capacitance sensing. The characterization of microscale objects, including microparticles and cells, is essential in various scientific disciplines, such as biology, materials science, and environmental science. Accurate identification and classification of these microscale entities are critical for applications ranging from drug delivery optimization to environmental impact assessment, however, the current techniques fall short in terms of the rapidity and cost-effectiveness necessary for analyzing extensive populations. To address this challenge, our hybrid sensor combines low-frequency impedance cytometry and high-frequency microwave capacitance sensing for material characterization based on dielectric permittivity. This integration offers a rapid, cost-effective, and highly accurate method for identifying and characterizing microscale particles and cells. Experimental studies demonstrate the sensor’s efficacy, achieving remarkable signal-to-noise ratios. The sensor’s versatility ex-tends monitoring permittivity changes in single cells exposed to fixing agents offering valuable insights into cellular properties. In summary, this thesis introduces an innovative multiphysical sensor that advances microscale entity analysis, enabling rapid and precise identification and characterization.