Highly sensitive microwave resonant near-field sensor for precise aqueous glucose detection in microfluidic medical applications

This paper presents a highly sensitive resonant near-field sensor to detect small variations of glucose concentrations in water. The sensor structure is based on a planar half-wavelength (lambda/2) microstrip line (MSL) resonator with a microfluidic container placed on top. The interaction between the electric field and the milliliter range water-glucose solutions under test can be observed measuring the magnitude shift of the S-parameter from 1.96 to 2.04 GHz. Combining the microwave detection and the microfluidic network, a time efficient and low cost architecture is presented. With this technique, a very sensitive water-glucose concentration of less than 50 mg/dl can be separated.