Authors: T. Alava, C. Ayela and L. Nicu
Affilation: Laboratory for Analysis and Architecture of systems LAAS-CNRS, France
Pages: 169 - 172
Keywords: piezoelectric thin film, multilayer micro-membrane, integrated actuation and read-out
In the field of piezoelectric-based resonators, micromembranes have revealed substantial advantages especially for biosensing experiments. To ease the design of new-membrane-based biosensors, an analytical model is crucial. We have elaborated such a model for the case of a micromembrane with piezoelectric actuation and detection vibrating in air or in a viscous fluid. The model has been synthesized as an equivalent electrical circuit enabling the direct computation of membranes specifics characteristics as biosensors, i.e. resonant frequency, mass sensitivity and minimum detectable mass. The model is established for a five layer stack micromembranes mounted with a circular piezoelectric cell. The methods used to establish the theory underlying the model are exposed for the case of vibration in air. The implementation of the model for the case of operation in a viscous fluid is detailed too. The fabrication of membranes with various geometrical configurations and the extraction of experimental dynamic behavior of the fabricated membranes operating in air and water are reported. The comparison between the theoretical data extracted from the model and the experimental behaviors is shown. Good accordance is reported between theoretical and experimental results.