In this work, we present a complete multiphysics modelling (via the Finite Element Method, FEM) of an air-coupled piezoelectric micromachined ultrasonic transducer (PMUT) with preliminary experimental validations. The PMUT is a suspended layered membrane, in which one of the layers is made of piezoelectric material. By means of an applied voltage over the piezoelectric layer thickness, the device emits acoustic waves in air. The model takes into account the multiple interactions between electrical, mechanical and acoustic fields, and in particular gives a realistic estimation of the device quality factor by means of a proper modelling of thermo-viscous losses in the fluid domain. The complexity of the model is increased by the presence of initial large deformations in the membrane and fabrication induced residual stresses. Preliminary experimental matchings are presented for static pre-deflection of the membrane due to residual stresses and for the eigenfrequency corresponding to acoustic wave emission.

Multiphysics analysis and experimental validation of an air coupled piezoelectric micromachined ultrasonic transducer with residual stresses

MASSIMINO, GIANLUCA;D'ALESSANDRO, LUCA;ARDITO, RAFFAELE;CORIGLIANO, ALBERTO
2016-01-01

Abstract

In this work, we present a complete multiphysics modelling (via the Finite Element Method, FEM) of an air-coupled piezoelectric micromachined ultrasonic transducer (PMUT) with preliminary experimental validations. The PMUT is a suspended layered membrane, in which one of the layers is made of piezoelectric material. By means of an applied voltage over the piezoelectric layer thickness, the device emits acoustic waves in air. The model takes into account the multiple interactions between electrical, mechanical and acoustic fields, and in particular gives a realistic estimation of the device quality factor by means of a proper modelling of thermo-viscous losses in the fluid domain. The complexity of the model is increased by the presence of initial large deformations in the membrane and fabrication induced residual stresses. Preliminary experimental matchings are presented for static pre-deflection of the membrane due to residual stresses and for the eigenfrequency corresponding to acoustic wave emission.
2016
Piezoelectric Micromachined Ultrasonic Transducers; Residual stresses; Static predeflection
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1022772
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