High precision integrated sensors for multi-parameter online monitoring in salt spray environments.

Detecting multiple parameters in salt spray environments is critical, as it significantly enhances the stability and reliability of real-time corrosion monitoring systems. However, current sensor strategies for detecting salt spray parameters face challenges such as poor timeliness, short lifespan, and low detection accuracy. This work introduces a multi-parameter micro-nano sensor based on Micro-Electro-Mechanical Systems (MEMS) technology, which integrates temperature, humidity, and conductivity detection units. Through a systematic characterization of the sensor's performance, the sensor demonstrates excellent linearity, ideal detection ranges, and satisfactory accuracies with detection accuracies of ±0.1 °C for temperature, ±2% RH for humidity, and ±0.1 mS/cm for conductivity. This sensor offers a practical strategy for calculating the instantaneous corrosion rate of aircraft over the ocean. Additionally, based on the positive correlation between the three parameters and the liquid film thickness, a critical threshold determination method for the dynamic behavior of the sensor surface liquid film is further explored. This method macroscopically distinguishes the phase transition boundary between dry and wet states of the liquid film, offering a theoretical foundation for differentiated corrosion rate assessment and improved corrosion prediction accuracy. High-precision monitoring of environmental parameters during long-term salt spray and atmospheric exposure experiments is achieved using a self-developed online testing system. Real-time data compensation is also provided to improve the sensor's stability and accuracy. Consequently, the proposed high-precision, miniaturized, and mass-producible multi-parameter sensor holds great promise as a competitive device for detecting salt spray environmental parameters in real-time corrosion monitoring systems for the aerospace field.