Highly Sensitive Differential 3-D Oblique-Gap Rectangular Sensor for Noninvasive Glucose-Level Monitoring

Blood glucose monitoring is crucial for managing diabetes, yet traditional finger-prick methods remain inconvenient and uncomfortable. Hypoglycemia (<70 mg/dL) causes immediate risks like confusion, while hyperglycemia (>140 mg/dL post-meal) leads to severe organ damage. This highlights the urgent need for non-invasive glucose sensing solutions to enhance patient care. This study presents an innovative, non-invasive 3D oblique gap rectangular resonator (OGRR) sensor designed to detect glucose concentrations ranging from 65 to 105 mg/dL. Employing a differential measurement technique, it minimizes systematic errors and enhances accuracy. Additionally, dielectric assessment kit (DAK-12) is utilized for precise glucose sample analysis. The sensor features a lightweight, compact design integrating oblique gap resonators and defected ground structures, resulting in amplitude sensitivity of 0.422 dB/(mg/dL) and frequency sensitivity of 3.6 MHz/(mg/dL). There is a good agreement between simulation and measurement results. With superior performance and cost-effectiveness, this sensor holds promise for glucose level monitoring in biomedical applications.