Liquids Microwave Characterization Technique Based on Quartz WGM Resonator with Microfluidic Chip

We present the accurate microwave characterization technique for investigation of liquids of nanoliters volumes. This technique is an improved modification of the previously developed approach based on a sapphire whispering gallery mode (WGM) resonator. It is based on a high-quality quartz WGM resonator with microfluidic chip. Experimental data are obtained in Ka-band for the aqueous solution of glucose studied down to the concentration equal to concentration of glucose in human blood. The detection limit of the technique for low molecular weight substances was found to be less than their concentration in real biological samples.