In this paper, we reported an ultra-sensitive millimeter wave reflection liquid sensor, which is electrically tunable, non-invasive and label-free. The reflection liquid sensor is based on the impedance match technique and implemented in a rectangular waveguide structure, which makes the interaction between millimeter wave and liquid under test (LUT) in a closed environment, forms a nano-fluidic lab-in-waveguide liquid sensor, and isolates the interference of surroundings. The reflection liquid sensor shows high sensitivity to the small complex-valued permittivity difference of the LUTs. Taking the ethanol-distilled water as the benchmark, a 64-dB ethanol-distilled water contrast is experimentally achieved. The detection limit is 0.05% ethanol in volumetric concentration with a 4-dB signal difference, which is the best performance of the microwave and millimeter wave liquid sensors publicly reported until now. The ultra-sensitive reflection sensor can be used for bio-chemical sensing. The lab-in-waveguide biosensor is also compatible with microfluidics.
He, G, Zhang, Y, De Tandt, C & Stiens, J 2019, 'A Fully Electronically Tunable Millimeter Wave lab-in-waveguide Nano-Fluidic Sensor', Journal of Physics D: Applied Physics, vol. 53, no. 9, pp. 095404. https://doi.org/10.1088/1361-6463/ab5ba6/meta
He, G., Zhang, Y., De Tandt, C., & Stiens, J. (2019). A Fully Electronically Tunable Millimeter Wave lab-in-waveguide Nano-Fluidic Sensor. Journal of Physics D: Applied Physics, 53(9), 095404. https://doi.org/10.1088/1361-6463/ab5ba6/meta
@article{9714eb1591c54c65b8fd86268dfa826d,
title = "A Fully Electronically Tunable Millimeter Wave lab-in-waveguide Nano-Fluidic Sensor",
abstract = "In this paper, we reported an ultra-sensitive millimeter wave reflection liquid sensor, which is electrically tunable, non-invasive and label-free. The reflection liquid sensor is based on the impedance match technique and implemented in a rectangular waveguide structure, which makes the interaction between millimeter wave and liquid under test (LUT) in a closed environment, forms a nano-fluidic lab-in-waveguide liquid sensor, and isolates the interference of surroundings. The reflection liquid sensor shows high sensitivity to the small complex-valued permittivity difference of the LUTs. Taking the ethanol-distilled water as the benchmark, a 64-dB ethanol-distilled water contrast is experimentally achieved. The detection limit is 0.05% ethanol in volumetric concentration with a 4-dB signal difference, which is the best performance of the microwave and millimeter wave liquid sensors publicly reported until now. The ultra-sensitive reflection sensor can be used for bio-chemical sensing. The lab-in-waveguide biosensor is also compatible with microfluidics.",
keywords = "THz, Microfluidics, Impedance matching, Liquid sensing, label-free sensing, non-invasive, electronically tunable",
author = "Guoqiang He and Yuchen Zhang and {De Tandt}, Cathleen and Johan Stiens",
year = "2019",
month = dec,
day = "20",
doi = "10.1088/1361-6463/ab5ba6/meta",
language = "English",
volume = "53",
pages = " 095404",
journal = "Journal of Physics D: Applied Physics",
issn = "0022-3727",
publisher = "IOP Publishing Ltd.",
number = "9",
}