Fully 3D-printed Microfluidic Substrate Integrated Waveguide based Sensor for in Vitro Diagnostics of Diabetes

This paper proposes a 3D-printed microwave sensor formed by a circular dielectric sample container embedded in a rectangular substrate-integrated waveguide (SIW) resonant cavity. The sensor element operating at 3.980 GHz is fabricated entirely by 3D printing using a novel additive manufacturing electronic (AME) technique that allows the entire sensor to be fabricated in a one-step process. The proposed sensor is a near-field probe to monitor glucose levels in aqueous solutions mimicking Type-2 diabetes. The sensor exhibits excellent sensitivity by tracking the change in amplitude of the reflection response ($S_{11}$) for the glucose sample tested (10-200 mg/dL), exceeding other studies. The ability of the 3D-printed sensor to detect changes in glucose concentration, sensitivity, and repeatability is demonstrated by in-laboratory measurements using a vector network analyzer (VNA).