Highly sensitive RF sensor based on microstrip meander line for measuring microfluidics dielectric properties of alcohol–alcohol mixtures

Abstract

In this paper, a radio frequency sensor for measuring microfluidics dielectric properties is designed based on microstrip meander line. The meander sensor replaces the straight transmission lines with meander transmission lines in the part of the half-wavelength path difference to improve the sensitivity of the sensor and reduce its size. According to the experimental results, the meander sensor based on the meander line has higher accuracy and a lower relative error than the straight sensor in measuring methanol–ethanol mixtures with different molar fractions. The relative error measured by the meander sensor after calibration with an adjustable cavity is less than 1%. It is easier to detect the very slight variation in dielectric properties brought about by microfluidics. The detection technique can be further applied for the accurate detection of dielectric properties of valuable biological samples, providing a more concise and convenient way.