High sensitive detection of flow rate and permittivity through microfluidics based on complementary split-ring resonators

This paper presents a high sensitive microfluidics flowmeter based on a complementary split-ring resonator (CSRR) sensor which can detect a tiny amount of 1.65 μL unknown fluid using permittivity estimation. The CSRR can detect the spatial distribution of the fluid to calculate the tangent flow rate. A multiring with tapped feeding is designed to improve the sensitivity and wide measurable dynamic range and to enhance the high resolution of position. Analysis of the sensor was calculated to estimate the resonance frequency. Microfluidics was fabricated using a glass substrate to achieve a high quality factor sensor. From the measured results, there is an average error of 6% using a single ring Rogers sensor. Moreover, the average error can be reduced to 3.35 % using the glass sensor.