Noncontact and simultaneous measurement of the d33 and d31 piezoelectric strain coefficients

Here, digital image correlation is demonstrated to be an accurate tool for the noncontact, non-destructive, and rapid characterization of the converse effect of piezoelectric materials. The longitudinal (d33) and transverse (d31) piezoelectric strain coefficients of lead zirconate titanate-5H wafers are measured simultaneously by imaging the wafer's cross section. The results are validated through laser interferometry and the large piezoresponse at switching domains is observed in strain-electric field butterfly loops. The proposed technique is simple and low cost requiring only an optical microscope and unlike indirect measurement methods requires little sample preparation and no information regarding the mechanical properties of the specimen.