Microwave Assisted Non-Invasive Microfluidic Biosensor for Monitoring Glucose Concentration

A novel design topology based on complementary split-ring resonator (CSRR) sensor integrated with the microfluidic channel is proposed to develop a non-invasive lab-on-a-chip microwave biosensor system. The microfluidic channel is designed using the polydimethylsiloxane (PDMS) which possesses chemical inertness and capacity to handle small volume of the liquid sample during the measurement procedure. The proposed microfluidic sensing methodology facilitates testing the biological samples which are usually available in very small volume
$(\pmb\mu \mathbf{L})$
. The design and optimization of the proposed sensor is carried out using the EM simulator CST-MWS at the designed frequency of 5.41 GHz. The S-parameters of fabricated prototype of the designed sensor measured under the unloaded condition are in close agreement with the corresponding simulated data. The fabricated sensor is used to test various volume proportions of water-glucose solutions by passing the solution across the sensing area in order to determine the suitability of the proposed device for biomedical application. The resonance frequency is recorded for each case, which is found to vary with the change in glucose concentration in the water. Finally, a graphical relationship between the measured resonance frequency and the glucose concentration is developed to detect any arbitrary concentration of the glucose in water.