Optimization of electrolyte‐insulator‐semiconductor capacitor sensor by differential design

Abstract An electrolyte‐insulator‐semiconductor capacitor (EISCAP) sensor with the unique differential design is proposed where a liquid‐free reference (LR) device is used as the reference signal source. After the output matching based on AC excitation adjustment, LR device can provide up to 80 % elimination efficiency of background signal for differential EISCAP sensor. Experiment results of pH sensing demonstrate that the differential EISCAP sensor has the better accuracy and time stability compared with conventional EISCAP sensor. The differential design provides a feasible optimization direction for EISCAP sensor in monitoring applications.