Highly sensitive blood glucose monitoring sensor with adjustable resonant frequency based on MP-CSRR

Abstract

In this paper, a multi parallel CSRR (MP-CSRR) sensor for non-invasive blood glucose monitoring is introduced. The sensor divides six CSRR units into two parallel circuits, forming 2 × 3 CSRR matrix to expand the sensing area of the sensor. This sensor can adjust the resonant frequency of the sensor itself by adjusting the spacing between the horizontal or vertical CSRR units. In this paper, the sensor is achieved a resonance frequency of 2.5–3.5 GHz after loading glucose solution. When the concentration of the solution changes, the resonance frequency and S21 depth of the resonator changes with the dielectric parameters of the solution. Thus, non-invasive monitoring of glucose concentration is achieved. The variation relationship between resonant frequency and CSRR unit spacing and the feasibility of using it for solution detection are verified through simulation. The experimental results are showed that the resonant frequency sensitivity of the sensor is 9.59 × 10−2 MHz/(mg/dL), and the |S21| sensitivity is 7.47 × 10−3 dB/(mg/dL).