Loading…
This event has ended. Visit the official site or create your own event on Sched.
Welcome to ICSV26!
Back To Schedule
Thursday, July 11 • 11:20 - 11:40
ACOUSTIC BEAM STEERING BY MEANS OF THE ACTIVE ACOUSTIC METASURFACE WITH AN ARRAY OF PIEZOELECTRIC MEMBRANES AND LOCAL CONTROL OF ACOUSTIC IMPEDANCE

Log in to save this to your schedule, view media, leave feedback and see who's attending!

Feedback form is now closed.
The control of the acoustic waves transmission, which is based on the generalized Snell's law, is in the spotlight of a research in the field of acoustic metasurfaces. It is due to its ability to arbitrarily modify the propagation direction of the sound wave, which passes through a thin interface. A limited number of successful implementation examples of the generalized Snell's law has been demonstrated so far. This phenomenon has been successfully demonstrated in a system, where the vibration wave has been transmitted through the resonant passive structures attached to the vibrating plate. Such structures are predominantly built for the fixed single-frequency excitation. The arbitrary frequency and the wide frequency range implementation of the generalized Snell's law can be achieved in acoustic systems, which allow tunable structures and whose versatility is achieved by means of the electronic control. In this work, we present the implementation of the generalized Snell's law in a system, where the sound wave propagates in air through the active acoustic metasurface (AAMS). The AAMS consists of the linear array of active electroacoustic elements with electronically tuned acoustic impedance. The electroacoustic element consists of the curved prestressed piezoelectric polymer membrane, which is connected to the active electronic shunt circuit. The effective electrical parameters of the shunt circuits control the spatial distribution of the specific acoustic impedance along the surface of the AAMS. When the proper adjustment of the spatial distribution of the specific acoustic impedance of the AAMS is used, it is possible to arbitrarily control the wavevector direction across the AAMS. The active shunt circuits are implemented as the Digital Synthetic Impedances (DSIs) in order to ensure the stability and the fine control of the specific acoustic impedance of the AAMS. Such an application of the generalized Snell's law requires the constant absolute value of the acoustic impedance along the AAMS interface and the linear change of the acoustic impedance phase along the AAMS. The overall stability is defined by properties of the PVDF foil and its support structure, which largely changes the geometry due to external mechanical stresses and temperature. Methods and results of the calibration of acoustic impedances will be discussed and the application of such metamaterial device in acoustic beam steering will be presented.


Thursday July 11, 2019 11:20 - 11:40 EDT
Westmount 3
  T02 Act. noise & vib. cntrl., SS03 Active meta-materials