A fully electronically tunable millimeter wave lab-in-waveguide nano-fluidic sensor. (20th December 2019)

• Record Type: Journal Article
• Authors: He, Guoqiang; Zhang, Yu-Chen; De Tandt, Cathleen; Stiens, Johan
• Is Part Of: Journal of physics. Volume 53:Number 9(2020)
• Publication Date: 2019-12-20
• Subjects: liquid sensor -- millimeter wave -- impedance match -- label-free -- non-invasive -- electronically tunable; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/ab5ba6
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: In this paper, we report an ultra-sensitive millimeter wave (mm-wave) reflection liquid sensor, which is electronically tunable, non-invasive, and label-free. The reflection liquid sensor is based on the impedance match technique. It is implemented in a rectangular waveguide structure, which makes the interaction between mm-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 permittivity change of the LUTs. Taking the ethanol-distilled water as benchmark, a more than 62 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 mm-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.