Proximity Capacitance Sensor Design for Noncontact Liquid Detection

The proximity capacitance sensor is presented to be a detector for liquid detection on membrane surface. Background of sensing technique was introduced in this paper. Three types of capacitance sensor in different shapes are designed and tested. According to the analysis, the parameters affecting the sensor performance and sensitivities are concluded. COMSOL software is used to simulate the electric distribution and penetration depth of the capacitance sensors. Associated with MATLAB programs, the performance of the designed sensor was simulated and compared. The experimental results proven the feasibility of the designed capacitance sensors used for liquid detection.