Improved Fully 3D-Printed SIW-Based Sensor for Non-Invasive Glucose Measurement

Area of Science:

• Microwave Engineering
• Biomedical Sensors
• Additive Manufacturing

Background:

• Diabetes mellitus requires continuous glucose monitoring for effective management.
• Existing glucose monitoring methods often involve invasive procedures or lack real-time, cost-effective solutions.
• Substrate-integrated waveguide (SIW) technology offers a platform for miniaturized, high-frequency devices.

Purpose of the Study:

• To develop and validate a fully 3D-printed microfluidic microwave sensor for non-invasive glucose level detection.
• To enhance sensor sensitivity and limit of detection (LOD) for improved diabetes monitoring.
• To demonstrate a cost-effective and compact solution for in vitro glucose measurement.

Main Methods:

• Design of a circular SIW cavity with an integrated sample holder for liquid under test (LUT).
• Utilization of a conductive sheath to improve field penetration and sensor performance.
• Fabrication using additive manufacturing electronics (AMEs) in a single pass without post-processing.
• Characterization of sensor performance by measuring S11 reflection response and resonance frequency shifts.

Main Results:

• The sensor achieved a high sensitivity of 1.218 MHz/(mg/dL) for glucose detection.
• A low limit of detection (LOD) of 0.774 mg/dL was obtained in the 10-200 mg/dL concentration range.
• The 3D-printed SIW sensor demonstrated accurate and reliable in vitro glucose measurements.
• The device operates at a resonance frequency around 5.740 GHz in the TM010 mode.

Conclusions:

• The fully 3D-printed microfluidic SIW sensor is a promising tool for non-invasive glucose monitoring in diabetic patients.
• The innovative AMEs fabrication method offers a compact, cost-effective, and efficient manufacturing process.
• The sensor's enhanced sensitivity and low LOD support its potential for clinical applications.