Design And Application Of Planar Capacitive Sensor Array

Planar capacitive sensor is a new type sensor based on the capacitance edge effect. Planar capacitive sensor array comprises a plurality of sensor units, integrates the functions of the sensor units. It is widely used in the composite inspection, food safety, environmental monitoring and has a good application value.In this thesis, the performance indexes of sensor array are introduced, the influence of geometrical parameters and structure on the indexes is studied, and the optimization method is improved. The design method of the backplane, shielding electrodes, driving electrodes, and sensing electrodes are given. Take 1×2 sensor array as example, the influence of arrangement, spacing, backplane, shield, and sensor unit on the crosstalk signal is analyzed.The planar capacitive sensor is used in food safety testing. The PCB type interdigital sensor with DNA modification gold electrodes is fabricated. And then, the detection of Ochratoxin A (OTA) in food mildew is implemented. The results show that the sensor can detect the presence of OTA on the surface of electrode. The resolution capability of OTA can be improve by increasing the sensitivity of the sensor.The applications of coplanar capacitance sensor array in plate flaw detection have been simulated. Take 2×2 single wavelength sensor arrays as example, compared the flaw detection effect of three kinds of sensor arrays. The interpolation algorithm and Canny Operator edge-detection is used. The results show that the detection effect of damage sample is good when the electrode shielding sensor array and the nearest neighbor interpolation algorithm are applied. And then,1×2 multi-wavelength sensor arrays are used for detecting the damage of different position and different depth, the simulation show the detection is effective.