This article presents a cost-effective step impedance resonator (SIR) for fluid concentration sensing. The sensing mechanism is based on the frequency resonant zero shifting by loading dielectrics with different electrical permittivity. The proposed biosensor mainly consists of two parts: a pair of SIRs and a microfluidic channel. The SIRs are fabricated on a PCB substrate feeding by straight microstrip lines. The microfluidic channel is made by a 3D printing technique. The microfluidic channel is loaded across the surface of the SIRs. The transmission frequency resonant zero is distinguishable by filling different concentrations of liquid. Electromagnetic numerical simulation is performed to verify the theoretical expectation, and glucose standard solution with different concentrations is finally used to demonstrate the feasibility of the proposed biosensor.

中文翻译：

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基于阶跃阻抗谐振器的高效低成本流体浓度传感生物传感器

本文介绍了一种用于流体浓度传感的经济高效的阶跃阻抗谐振器 (SIR)。传感机制基于通过加载具有不同介电常数的电介质来实现频率谐振零移。所提出的生物传感器主要由两部分组成：一对 SIR 和一个微流体通道。SIR 是在由直微带线馈电的 PCB 基板上制造的。微流体通道由 3D 打印技术制成。微流体通道加载在 SIR 的表面。通过填充不同浓度的液体可以区分传输频率谐振零。进行电磁数值模拟以验证理论预期，