Novel sensor technology for shear and normal strain detection with generalized electrostriction

Abstract

We present a novel technology for stress and strain sensing. As a fundamental property of any dielectric material, electrostriction determines the effect of elastic deformation on dielectric properties. An electrostriction sensor detects the dielectric changes due to deformation in the media with a data acquisition approach, which resembles well-known capacitance sensing techniques. Electrostriction sensing technology does not rely on mechanical contact between the sensor electrodes and the sensing media, nor does it require physical displacement of the electrodes. Thus, detection of normal and shear loads can be implemented in a single plate configuration with no moving parts. Electrostriction sensor design is robust and has high tolerance to overloads - a critical issue for tactile sensing in robotic applications. With many materials available for sensing media, we discuss electrostriction phenomenon in isotropic and anisotropic polymer composites and provide guidance for selection of a material for a given application.