This paper presents a numerical reduced-order modeling (ROM) approach for complex multi-layered arrays of piezoelectric micromachined ultrasonic transducers (PMUTs). The numerical modeling technique adopted to generate an array of PMUTs consisting of a considerable number of transducers allows for a large reduction in computational cost without reducing accuracy. The modeling idea is based on coupling shell elements applied to the PMUT structural layers with 3D-solid elements applied to the piezoelectric layer. A set of eigenfrequency and frequency domain analyses are presented considering a single ROM of a PMUT performing in different ambients and the performing central frequencies are obtained for every considered scenario. A unique arrangement of 228 PMUTs is presented and tested for its ability to transmit and receive acoustic waves. The operating frequency band of the array and the level of interference and cross-talk among different PMUTs in the near field are estimated. Finally, the results from a preliminary experimental test performed to analyze the acoustic abilities of an 8 × 8 array of PMUTs are presented. A corresponding numerical model is created and the obtained results matched the experimental data, leading to a validation of the modeling technique proposed in this work.
Keywords: acoustic–structure interaction; multiphysics modeling; piezoelectric micromachined ultrasonic transducers (PMUTs); reduced order modeling (ROM); ultrasound.