Millimetre-Wave Metamaterial-Based Sensor for Characterisation of Cooking Oils

Abstract

The characterisation of the cooking oils presents a significant challenge due to minor changes in their dielectric behaviour. In this paper, a new metamaterial-based sensor incorporating a split-ring resonator (SRR) with a microstrip transmission line is presented to characterise cooking oils. The design demonstrates metamaterial characteristics of negative permittivity and permeability simultaneously at the resonance frequency. Furthermore, its operation in the range of millimetre-wave frequencies can further enhance its sensitivity, especially for liquid materials. The sensor’s novelty is the operation at millimetre-wave frequencies that offers a high shift in the transmission coefficient while operating at 30 GHz. The sensor’s performance analysis is undertaken by using six MUTs with dielectric constants ranging from 0.126 to 4.47. The presented structure designed on 12 × 8 mm2 Rogers substrate offers a sensitivity of 1.12 GHz per unit change in dielectric constant. The phase's shift demonstrates a lower percentage error than the amplitude and linearly moves towards higher frequencies with the increase in dielectric constant and tangent loss of MUT. The designed sensor can be prominently useful for detecting liquids' chemical characteristics in chemistry and medicine fields.

Microwave Spoof Surface Plasmon Polariton-Based Sensor for Ultrasensitive Detection of Liquid Analyte Dielectric Constant

“…Moreover, the proposed sensor uses less than 1 mL of sample, which reduces the amount of used samples comparing to sensors that have to be immersed during testing. Additionally, the sensor provides high sensitivity, and while the structures in [ 10 , 14 ] have better sensitivity, they require more complex fabrication procedures and operations at higher frequencies, consequently requiring more expensive equipment. Furthermore, the structure in [ 14 ] has not been confirmed experimentally.…”

“…Additionally, the sensor provides high sensitivity, and while the structures in [ 10 , 14 ] have better sensitivity, they require more complex fabrication procedures and operations at higher frequencies, consequently requiring more expensive equipment. Furthermore, the structure in [ 14 ] has not been confirmed experimentally. In addition, the proposed sensor has an excellent linearity, which outperforms linearities of other solutions.…”

“…Due to their possibility for real-time, non-contact and non-invasive measurements, microwave sensors present an excellent solution for a wide range of applications, including dielectric constant sensing [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ], food quality control [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ], gas sensing [ 20 , 21 , 22 ], detection of biomolecules [ 23 , 24 ], glucose monitoring [ 25 , 26 ], measurements of concentration for liquid solutions [ 27 , 28 ], microwave imaging [ 29 , 30 ], and mechanical motion sensing [ 31 , 32 ]. They can also be combined with other technologies, including microfluidics, which provide compact and cost-effective platforms for rapid detection in small amounts of liquid samples [ 33 , 34 , 35 , 36 ].…”

“…They can also be combined with other technologies, including microfluidics, which provide compact and cost-effective platforms for rapid detection in small amounts of liquid samples [ 33 , 34 , 35 , 36 ]. Although there have been a number of attempts to increase their sensitivity, including employment of split-ring resonators (SRR) [ 3 , 14 , 19 , 37 ], transmission lines [ 15 ], meta-surface absorbers [ 16 ], patch resonators [ 18 ], most microwave sensors do not have the ability to detect small changes in dielectric constant, and they are usually proposed for detection in the wide range of values, for applications that do not require accurate detection.…”

“…One of the potential applications of microwave sensors in which the sensitive response can provide valuable information about the sample is edible oil quality control. In that sense, dielectric spectroscopy has been used for the detection of adulteration [ 63 ], chemical composition [ 64 , 65 ], quality of edible oils [ 13 ], frying oil degradation [ 11 , 12 ], characterization of cooking oils [ 14 ], usage time of oil [ 15 ], and identification of oils [ 16 , 17 ], however, usually lacking high sensitivity and accuracy.…”