Parametric Analysis of Blood Dielectric Properties Using a Printed Microwave Antenna Sensor for In-Vitro Glucose Detection

More and more people are suffering from diabetes mellitus, a condition that requires accurate, non-invasive, and cost-effective ways to monitor blood sugar levels. Painful and limiting, traditional finger-pricking procedures restrict the frequency of examinations. Using changes in blood's dielectric characteristics as a basis, this research details the design and development of a miniature printed microwave antenna sensor for in-vitro glucose detection. Utilised ANSYS HFSS for analysis after designing a 5.5 GHz ISM band concentric rectangular loop Microstrip antenna utilising an inexpensive FR-4 substrate. A multi-layer phantom model of the human fingertip was used to replicate realistic sensing settings. This model incorporates skin, fat, blood, and bone components. Changes in the dielectric characteristics of blood caused by fluctuations in glucose allow for changes in the resonance frequency of the reflection coefficient (S_11), which in turn allow for changes in the sensing. Additionally, by individually adjusting the relative permittivity, conductivity, and loss tangent of blood, a comprehensive parametric analysis was carried out. According to the findings, resonance frequency shifts are greatly impacted by relative permittivity, but signal loss is largely affected by conductivity and loss tangent, and frequency shifts are barely affected by any of these parameters. In comparison to earlier reported microwave glucose sensors, ours showed a large resonance shift of 2.05 GHz upon phantom introduction, suggesting excellent sensitivity. The suggested antenna sensor has enormous potential for use in future non-invasive glucose monitoring systems due to its small size, ease of fabrication, and enhanced sensitivity.