High-sensitivity Planar Microfluidic Sensor Based on Zeroth-Order Resonance

A high-sensitivity planar microfluidic sensor based on zero-order resonant mode is proposed in this paper. By short-circuiting the composite left/right-handed transmission line (CRLH TL) structure with grounded wires, the zeroth-order resonance is completely determined by the series element. A high sensitivity for dielectric loading on the metal surface is achieved by including appropriate surface capacitors in the resonator, which can be converted into a shift of the resonant frequency. Compared to other conventional microwave microfluidic sensors made of planar resonators, the sensitivity of the proposed sensor is greatly improved. In addition, a water-ethanol mixture was used for verification.