Phononic band gap and wave propagation on polyvinylidene fluoride-based acoustic metamaterials

Oral Oltulu,Sevket Simsek,Ekmel Ozbay,Amirullah M Mamedov,Rajeev Ahuja

doi:10.1080/23311940.2016.1169570

Abstract

In the present work, the acoustic band structure of a two-dimensional phononic crystal (PC) containing an organic ferroelectric (PVDF-polyvinylidene fluoride) and topological insulator (SnTe) was investigated by the plane-wave-expansion (PWE) method. Two-dimensional PC with square lattices composed of SnTe cylindrical rods embedded in the PVDF matrix is studied to find the allowed and stop bands for the waves of certain energy. Phononic band diagram ω = ω(k) for a 2D PC, in which non-dimensional frequencies ωa/2πc (c-velocity of wave) were plotted vs. the wavevector k along the Г–X–M–Г path in the square Brillouin zone shows five stop bands in the frequency range between 10 and 110 kHz. The ferroelectric properties of PVDF and the unusual properties of SnTe as a topological material give us the ability to control the wave propagation through the PC over a wide frequency range of 103–106 Hz. SnTe is a discrete component that allows conducting electricity on its surface but shows insulator properties through its bulk volume. Tin telluride is considered as an acoustic topological insulator as the extension of topological insulators into the field of “topological phononics”.

Highlights

Phononic crystals (PCs) and acoustic metamaterials have generated increasing scientific interest for very diverse technological applications ranging from sound abatement to ultrasonic imaging to telecommunications to thermal management and thermoelectricity (Pennec, Djafari-Rouhani, Larabi, Vasseur, & Hladky-Hennion, 2009)
Numerical calculation in this study has the parameters with the column radius of 16.5 mm and the lattice size of a = b = 33 mm for an array of circular SnTe cylinders embedded in a PVDF background material
In the present paper, we initially discussed the band structure of two-dimensional PC composed of a topological material embedded in a polymer host

Summary

Introduction

Phononic crystals (PCs) and acoustic metamaterials have generated increasing scientific interest for very diverse technological applications ranging from sound abatement to ultrasonic imaging to telecommunications to thermal management and thermoelectricity (Pennec, Djafari-Rouhani, Larabi, Vasseur, & Hladky-Hennion, 2009). Phononic crystals (PCs) are composite materials that are artificially manufactured structures with special properties regarding wave propagation, known as acoustic metamaterials. PCs and acoustic metamaterials are artificially structured composite materials that enable the manipulation of the dispersive properties of vibrational waves in ways that are not possible in conventional materials.

Results

Conclusion