MEASUREMENT OF SURFACE DISPLACEMENTS IN 1-3-PIEZOCOMPOSITE AND 1-1-3-PIEZOCOMPOSITE

In a piezoelectric ceramic-polymer composite, the piezoceramic and the nonpiezoelectric polymer will have different deformations when subjec ted to an external electrical or mechanical stimulus. This local, nonu niform deformation eventually determines the overall electromechanical behavior of the composite. In the current investigation, static surfa ce displacements of piezocomposites with 1-3 and 1-1-3 connectivity we re measured using a scanning heterodyne laser interferometer. The infl uence of a thin interlayer surrounding the piezoceramic rods on the re sulting displacement profiles was investigated and correlated with rod /polymer adhesion. The elastic stiffness of the interlayer as well as the interfacial adhesion had a significant effect on the rod displacem ent. Rods coated with a very compliant interlayer had a much larger di splacement than untreated rods, while rods treated with a silane coupl ing agent to enhance adhesion had a much lower displacement. Experimen tal displacement profiles were found to be in good agreement with theo retical predictions. (C) 1996 American Institute of Physics.