Development of a novel force sensor system built with an industrial multilayer ceramic capacitor (MLCC)

This paper presents the development and normalization of a novel sensor system built with low-cost industrial-grade multilayer ceramic capacitors (MLCC). MLCCs play both the roles of force sensing elements and force sustaining elements. With adopting this low-cost industrial component of MLCC (less than 1 cent USD for a sensing component), the time and the cost for producing a high performance force sensor system can be achieved. Practically, industrial-grade MLCCs are produced for capacitor applications but not for a sensing element for force measurement. However, the sensitivity for each independent MLCC presents a large variation for force sensing (coefficient of variation around 0.6). This study successfully overcome this drawback, a simple poling process is demonstrated to both increase the sensitivity and to reduce the variation coefficient of MLCC force sensors. Results indicate that the variation for the MLCCs after re-poling treatment is reduced to 0.02. The effects on the poling voltage and poling time are experimentally investigated. Results show that the MLCC treated with a high poling field can increase sensitivity and also reduce the variation for force sensing. This re-poling treatment is essential for developing a simple and low cost MLCC-based force sensor system that can be used in a wide variety of applications.