Resonant Coupling of Piezoelectric Micromachined Ultrasound Transducers with Polymer Specimens in Different Media

There is a need for a non-destructive assessment method of polymeric materials as they are ageing during fluid exposure. It is assumed that in instances where chemical or physical alterations occur, then the elastic properties will be altered. The output characteristics of an embedded sensor could be used for assessment and tracking over time. In response, this study marks the first of a series in analyzing the feasibility of piezoelectric micromachined ultrasound transducers (PMUTs) to characterize polymer specimens nondestructively through a medium of fluid, starting the design with air. The study is conducted by considering a 3D replica of a bespoke experimental setup using COMSOL Multiphysics ® software simulation. The validation with experimental work will be conducted in a subsequent study, using PMUTs manufactured through the PiezoMUMPs fabrication flow. The current study aims to characterize the 3-layer model (PMUT-medium-polymer) for the analysis of the effect of medium fluid type, input voltage, and distance on resonant coupling of PMUT and polymer specimen. Additionally, the study compares 1-port and 2-port T/R configurations with a view towards guiding experimental design.