High-overtone Bulk-Acoustic Resonator gravimetric sensitivity: towards wideband acoustic spectroscopy

TL;DR

This paper explores the gravimetric sensitivity of high-overtone bulk acoustic resonators for wideband acoustic spectroscopy, combining modeling and experiments to enhance detection capabilities in compact sensors.

Contribution

It introduces a comprehensive analysis of gravimetric sensitivity in high-overtone bulk acoustic resonators and proposes methods to improve sensitivity by acoustic field confinement.

Findings

Modeling and experimental validation of gravimetric sensitivity.

Identification of multimode spectral characteristics for wideband spectroscopy.

Theoretical methods to enhance sensitivity via acoustic field confinement.

Abstract

In the context of direct detection sensors with compact dimensions, we investigate the gravimetric sensitivity of High-overtone Bulk Acoustic Resonators, through modeling of their acoustic characteristics and experiment. The high frequency characterizing such devices is expected to induce a significant effect when the acoustic field boundary conditions are modified by a thin adlayer. Furthermore, the multimode spectral characteristics is considered for wideband acoustic spectroscopy of the adlayer, once the gravimetric sensitivity dependence of the various overtones is established. Finally, means of improving the gravimetric sensitivity by confining the acoustic field in a low acoustic-impedance layer is theoretically established.