Non-destructive detection method based on two-channel coplanar capacitive sensor

Abstract

To overcome the shortcomings of the existing rectangular electrode coplanar capacitive sensor used in the non-destructive detection, such as poor adaptability to the uneven distribution of medium, small dynamic range and low sensitivity, a two channel coplanar capacitive sensor with triangular electrode is proposed, and a method of applying it to non-destructive detection is discussed. Firstly, the sensor structure and mathematical model of the novel coplanar capacitive sensor is established, and the sensor related performance indexes are analyzed and defined. By establishing a three-dimensional simulation model of the sensor, the influence of sensor structure parameters such as working electrode, shielding electrode, protective electrode and substrate thickness on its performance indexes is systematically analyzed. Through studying the correspondence between different performance indexes and structural parameters, the linear relationship between the penetration depth of sensor and the electrode structure parameters is established. Finally, experiments are conducted to evaluate its performance on non-destructive detection.