Millimeter wave and terahertz dielectric probe microfluidic sensors

This paper reports the design, fabrication, and characterization of a suite of dielectric probes for near-field and evanescent microfluidic sensing applications. Four different probe designs are studied. These structures are made from cylindrical alumina dielectric rods, and were integrated with microfluidic channels. Mixtures of two different solvents were used to characterize the probes. The sensitivity of the probes is measured under a continuous flow of liquids in the microfluidic channel. In comparison to evanescent wave probes, an improvement of up to 25X in sensitivity is obtained using the new probes.