Characterization of piezoelectric bimorph actuator 3d-deformations caused by electric change by means of multiscale curvature analysis

The objective of this work is to demonstrate the use of multiscale curvature tensor analysis to characterize deformations of piezoelectric bimorph actuator and to study the relation between loaded electric charge and the resulting deformed surface curvature. In particular, the strength of the correlations between surface shape characterized by curvature parameters (i.e., principal, Gaussian or mean curvature) and charge density is sought. The impact that the scale of the analysis of the curvature can have on the values of the curvature parameters for the deformed surfaces and the correlation with discharge energy is also studied. In this study the deformations of piezoelectric bimorph actuators are studied. In order to achieve quasi-static measurements, a dedicated charge amplifier was built to supply charge to the actuator. The deformations were then measured by Polytec® 3D laser scanning vibrometer PSV-400 by integration of captured motion. The obtained data was used to calculate curvature tensor field at multiple scales by applying the normal-based method. Principal, mean and Gaussian curvature was calculated at multiple scales and were correlated with applied charge. The obtained results contribute to better understanding of piezoelectric behavior under electric field.