Evaluation of polarization of embedded piezoelectrics by the thermal wave method

Abstract

This work demonstrates the benefit of the thermal wave method for the evaluation of the polarization state and the polarization profile, respectively, of embedded piezoelectrics. Two types of samples were investigated: A Low Temperature Cofired Ceramics (L TCC)/PZT sensor-actuator and a Macro Fiber Composite (MFC) actuator. At modulation frequencies below 10 Hz, the pyroelectric response was governed by thermal losses to the embedding layers. Here, the sample behavior was described by a harmonically heated piezoelectric plate exhibiting heat losses to the environment characterized by a thermal relaxation time.

Evaluation of polarisation state of light metal embedded piezoelectrics

“…1 To ensure the functionality of the integrated piezoelectric modules after the fabrication process, the polarisation state is determined non-destructively by thermal wave methods. 2 The devices are irradiated by a modulated laser beam, and the time or frequency dependences of the pyroelectric current are recorded, which provide insight into the polarisation distribution.…”