Modeling of capacitive sensor filled with elastic dielectrics and its advantages

Abstract

Electrostriction phenomena and mathematical modeling in respect of capacitive sensor filled with elastic dielectric material have been described. A comparative theoretical analysis of the traditional air gap capacitive sensor with the electrostriction based solid-state capacitive sensor has been carried out thoroughly. Difficulties and limitations with air gap capacitive sensor are highlighted. Solid-state capacitive sensor with elastic dielectric material sandwiched between the compliant electrodes exhibits higher mechanical and electrical stability, sensitivity, higher tolerance with environment and withstands large load in comparison to the air gap capacitive sensor. An experimental setup with proper solution has been described for the measurement of relative capacitance variation. An alternative method of current-mode bridge has also been suggested for the purpose of sensing pressure and strain with high accuracy.