High-Sensitivity Microwave Metamaterials Sensor Absorber for Chemical Liquids Detection

A metamaterial (MTM) absorber-based chemical sensor is realized both numerically and experimentally by incorporating swastika shaped resonator in X-band frequency range (8-12 GHz). The proposed sensors can be used to measure the electrical characteristics of chemical liquids namely, acetone, methanol, ethanol, Polyethylene Glycol 300 (PEG 300), water, ethanol mixed with water and methanol mixed with water. The structure composed three main layers, from the top to bottom as follows: swastika shaped resonator, FR4 substrate and ground layer, between the copper ground film and backside resonator have an air gap to put chemical liquids. We used CST Microwave Studio to get the simulated results and observe the absorption spectrum. In this work to measure experimental studies vector network analyzer (VNA) and a dielectric probe kit are used to determine the dielectric constants and dielectric loss factor of the selected samples in the related frequency range. According to the simulated results, there is a highly different in the absorption spectrum between each liquid and the shifting total resonance frequency indicated the accurate information to estimate the density of the sensing water mixture with ethanol and methanol In the electrochemical approach, the proposed sensor structure can be improving to detect the different chemical liquids