Design of flexible piezoelectric gyroscope for structural health monitoring

Abstract

This Letter reports a piezoelectric bending sensor configuration based on a complementary design of four identical flexible piezoelectric sensors using both theoretical analysis and experimental demonstration. The active material used here for sensing is a flexible ferroelectret polymer, which possesses a cellular internal structure with distributed trapped charges. The transverse piezoelectric effect is observed by changing the permanent macroscaled dipole moments upon bending. It has been found that the voltage output for the sensor is linearly related to the bending curvature. Angular displacement is determined by monitoring the output of four orthogonal devices on a rod. Different types of surface stress can also be determined by measuring output polarities from an antiparallel electrical connection. The proposed sensor configuration in this work is capable of providing a nondestructive evaluation of structural health by measuring a 2D bending vector.