Microwave Microfluidic Sensor Based on Spoof Localized Surface Plasmons for Monitoring Lubricating Oil Quality

Abstract

This letter proposes a sensor based on a modified hybridized spoof localized surface plasmons (SLSPs) structure, which consists of two concentric overlapped SLSP resonators. The degree of overlap between two structures is adjusted to control the resonance effect. Through the design of overlapped SLSP structure, the coupling is enhanced, thereby reducing the resonance frequency. The proposed sensor exhibits a high-quality factor and high sensitivity. A prototype of the sensor is fabricated and tested, and the experimental results demonstrate that the proposed sensor has a promising potential for lubricating oil quality monitoring.