Dual-coil micro-impedance resonance oil contaminant detection sensor based on microfluidic chip

A dual-coil micro-impedance resonant sensor for on-line detection and impurity analysis of mechanical oil systems was designed in this experiment. Through the design of the double coil, inductance detection and capacitance detection are realized on the same chip. Furthermore, the resonant circuit formed by the sensor plus an inductive element and a capacitive element further improves the detection sensitivity of the sensor. This paper establishes a resonant circuit model and conducts theoretical analysis. It verifies the accuracy of theoretical analysis by comparing the micro-impedance resonant sensor with the sensor without micro-impedance resonance. It is confirmed that the resonant sensor has better detection sensitivity. The experimental results determine the frequency characteristics and the optimal frequency of the resonant sensor. This paper has a guiding role in the design of such sensors, and providing technical support for the development of online detection. [Display omitted] •A dual-coil micro-impedance resonant sensor for on-line detection and impurity analysis of mechanical oil systems is proposed.•The optimal excitation frequency for detecting different oil contaminants is also different.•The sensor can realize to detect a variety of contaminants such as ferromagnetic metal particles, non-ferromagnetic metal particles, water droplets and air bubbles in oil, and has a higher detection accuracy.