Engine Oil Quality Monitoring Using a GaAs-Based Tribo-Photonic Sensor

The study aims to design a photonic crystal-based oil sensor that continuously monitors engine oil, enabling faster detection of oil degradation stages compared to existing technologies such as microscopic techniques, spectroscopy, and field experience. GaAs composite rods featuring an air backdrop lattice serve as the fundamental components of the photonic crystal structure utilized in the proposed sensor. The FDTD approaches allow optical and dispersion properties to be examined in a label-free sensing environment. The sensing mechanism relies on the change in refractive index leading to a shift in the resonant wavelength. Opti-FDTD software has been used to design and simulate the sensor. The results show that the tribo-photonic sensor has a high sensitivity of 590.49 nm/RIU, a high Q-factor of 9332.03, a low detection limit (δ) of 341.17 × 10-6 RIU, a high FOM of 2931.01 RIU-1, and a compact area of 47.63 μm2.