Design of Autonomous Miniaturized Spherical Acoustic Sensor for Complexe Media Characterization

In this work, a spherical device (1 cm in diameter) composed of two assembled hemispherical shells integrating both the active element (piezoelectric ring) and the integrated electronics dedicated to coding, control and analysis was developed as an acoustic sensor. This autonomous sensor can operate simultaneously as a transmitter and a receiver around its fundamental frequency (32 kHz). Viewing these characteristics, operation within a sensor network could be envisaged and it will be possible to map the acoustic properties of a given medium characterized by a heterogeneous dispersion due to imposed dynamic motion.