In this paper, a new metamaterials-based hypersensitized liquid sensor integrating omega-shaped resonator with microstrip transmission line is proposed. Microwave transmission responses to industrial energy-based liquids are investigated intensively from both numerical and experimental point of view. Simulation results concerning three-dimensional electromagnetic fields have shown that the transmission coefficient of the resonator could be monitored by the magnetic coupling between the transmission line and omega resonator. This sensor structure has been examined by methanol–water and ethanol–water mixtures. Moreover, the designed sensor is demonstrated to be very sensitive for identifying clean and waste transformer oils. A linear response characteristic of shifting the resonance frequency upon the increment of chemical contents/concentrations or changing the oil condition is observed. In addition to the high agreement of transmission coefficients (S21) between simulations and experiments, obvious resonant-frequency shift of transmission spectrum is recognized for typical pure chemical liquids (i.e., PEG 300, isopropyl alcohol, PEG1500, ammonia, and water), giving rise to identify the type and concentration of the chemical liquids. The novelty of the work is to utilize Q factor and minimum value of S21 as sensing agent in the proposed structure, which are seen to be well compatible at different frequencies ranging from 1–20 GHz. This metamaterial integrated transmission line-based sensor is considered to be promising candidate for precise detection of fluidics and for applications in the field of medicine and chemistry.

In this study, the labyrinth resonator based chemical liquid and transformer oil condition sensor are presented in a microwave frequency range both numerically and experimentally. The transmission coefficient is observed by the magnetic coupling between the transmission line and resonator which also contain a sensing layer. The sensor structure is tested with the ethanol-water mixtures, methanol-water mixtures and different kind of pure chemical fluidics. In addition, the proposed sensor is used for distinguishing the waste and clean transformer oil sensitively. In the chemical liquids sensing study, linear response characteristics of the sensor have been investigated by the resonance frequency shifts for ethanol-water and methanol-water mixtures. The frequency shifts for each 10% steps of ethanol and methanol content have been monitored as about 25 MHz and 15 MHz, respectively. In the transformer oil condition sensing study, non-destructive methods have been used for providing the long term stability of the sensor structure. In addition, the measured response time between the signal applied from the input port and observation of the transmitted signal from the output port is around 5ns. This value is consistent with the period of the applied signal and the length of the receiver/transmitter cables and the sensor circuit.

In this study, Chiral Metamaterial Sensor (CMS), which is designed by utilizing a Split Ring Resonators (SRR) has been employed to reveal the two different types of sensor applications by experimentally and numerically. These applications include purity demonstration of methanol, ethanol and isopropyl alcohol (IPA) and fuel adulteration applications for petrol. All of the validations have been realized by measuring the complex permittivity values and reflection coefficients by using a vector network analyzer and a sample holder. For simulation, FIT based simulation program is employed. Both numerical and experimental study results are complying with each other. Sample holder which is developed in this study for microfluidic measurements can easily be tuned for other microfluidic sensor applications thanks to its unique design. Having 280MHz bandwidth with −40dB signal level indicates that the proposed structure is highly sensitive and gives a linear output according to purity and adulteration applications. Whereas, there are many metamaterial researches on purity applications in literature, this is the first study that investigates the purity of methanol, ethanol, isopropyl alcohol (IPA) and fuel adulteration of petrol by using a novel chiral metamaterial sensor designed specifically for the proposed applications.