Electrostriction enhancement of solid-state capacitance sensing

This paper analyzes the performance of a solid-state capacitance sensor that extends classical modeling to incorporate an electrostriction model of isotropic linear elastic dielectrics. A capacitance sensor which incorporates an elastic dielectric layer between the electrodes exhibits higher sensitivity and is more robust than its air-gap or vacuum-gap counterparts. Sensors with polyester and urethane polymer dielectric layers are tested for the response to normal loads and are compared with air-gap setups of same geometry. Experimental data suggest that the solid-state sensor has linear response in loads range up to six orders of magnitude and demonstrates a two to three times stronger output signal than air-gap designs. Potential for future development and application of solid capacitance sensors is discussed.