Simulation and Experimental Validation of a Flexural Plate Wave Piezoelectric MEMS Transducer

The analysis and experimental validation of the frequency response of the electrical conductance of a piezoelectric micro electro-mechanical systems (MEMS) Flexural Plate Wave (FPW) transducer is investigated in this paper. FPW MEMS transducers are an attractive research field due to the considerable number of possible applications such as vibration, pressure, humidity measurements, chemical vapour and gas detection, biosensing, and lab-on-chip development. To this extent, this work proposes a theoretical analysis supported by finite element modelling (FEM) by means of COMSOL Multiphysics® and LTspice modelling of a flexural plate waves piezoelectric MEMS transducer configured as a one-port device. The transducer embeds an aluminum interdigital transducer (IDT) located close to the edge of a squared diaphragm composed of a silicon (Si) and a piezoelectric aluminum nitride (AIN) layer. The developed analysis together with the FEM and LTspice simulations have been experimentally validated by employing a fabricated MEMS transducer. The presence of multiple standing waves was correctly detected within the expected bandwidth, in good agreement with theoretical predictions.