Metamaterial inspired sensor for detection of engine lubricant oil condition

A metamaterial (MTM) based sensor structure is proposed to determine engine lubricant condition at X band frequency regime. The resonator part of the structure is inspired electric LC resonator (ELC) type MTM which is highly used among the researchers. The sensing application is realized by benefiting the electrical properties of the lubricant samples. The dielectric characteristics of the clean and waste lubricant oils are measured by using a vector network analyzer and dielectric probe kit. The dielectric values are observed as about 2.35+j0.31 and 2.45+j0.34 for clean and waste oil samples, respectively. After, the ELC resonator based sensor structure are designed by including a sensor layer at the back. Finally, transmission resonance frequencies and phases are measured for both samples. The transmission coefficients are obtained nearly zero at 8.572 GHz and 8.664 GHz. Hence, the proposed sensor structure can distinguish the clean and waste lubricant oil samples with about 100 MHz.