Large-area piezoceramic coating with IDT electrodes for ultrasonic sensing applications

Abstract

In the present paper, the ultrasonic strain sensing performance of large-area piezoceramic coating with Inter Digital Transducer (IDT) electrodes is studied. The piezoceramic coating is prepared using slurry coating technique and the piezoelectric phase is achieved by poling under DC field. To study the sensing performance of the piezoceramic coating with IDT electrodes for strain induced by the guided waves, the piezoceramic coating is fabricated on the surface of a beam specimen at one end and the ultrasonic guided waves are launched with a piezoelectric wafer bonded on another end. Often a wider frequency band of operation is needed for the effective implementation of the sensors in the Structural Health Monitoring (SHM) of various structures, for different types of damages. A wider frequency band of operation is achieved in the present study by considering the variation in the number of IDT electrodes in the contribution of voltage for the induced dynamic strain. In the present work, the fabricated piezoceramic coatings with IDT electrodes have been characterized for dynamic strain sensing applications using guided wave technique at various different frequencies.Strain levels of the launched guided wave are varied by varying the magnitude of the input voltage sent to the actuator. Sensitivity variation with the variation in the strain levels of guided wave is studied for the combination of different number of IDT electrodes. Piezoelectric coefficient 11 e is determined at different frequencies and at different strain levels using the guided wave technique.

Ultrasonic guided wave sensing properties of PVDF thin film with inter digital electrodes

“…20 . This problem is solved by IDT electrodes which also has advantages of tuning with frequency 31 . PVDF with IDE can have both positive and negative electrodes on same surface as shown in Fig.…”

“…18 . Manka et al 19 studied the beam pattern generated by phased array inter digital transducers with 31 d effect using laser Doppler vibrometer. Bent and Hagood 20 found higher in-plane actuation in piezoelectric fiber composites with interdigitated electrodes as compared to monolithic piezoceramic wafers.…”

“…A guided wave technique to estimate the piezoelectric coefficient 31 e at any frequency as discussed in Refs. [29][30][31] is extended for the estimation for the piezoelectric coefficient 11 e in present work. Method of preparation of these large-area IDE-PVDF and their basic characterization studies are reported in Sec.…”

“…28 . Rathod et al reported a method to estimate piezoelectric coefficient 31 e of the PVDF films at ultrasonic frequency range using the technique of guided waves 29 . Degradation of the piezoelectric properties at elevated temperature was also discussed.…”

“…Using the technique of guided waves as reported in Ref. 30 , piezoceramic coating with IDEs was characterized for ultrasonic applications by determining the piezoelectric coefficient 31 e in frequency range of 80-180 kHz 31 . However the directional sensitivity was not analyzed which is a unique property of a piezoelectric sensor with IDEs.…”