Thermal Tuning of Band Structures in a One-Dimensional Phononic Crystal

2013 ◽  
Vol 81 (4) ◽  
Author(s):  
Zuguang Bian ◽  
Wei Peng ◽  
Jizhou Song
Keyword(s):  
Band Gap ◽  
Acoustic Waves ◽  
Vibration Isolation ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Polybutylene Terephthalate ◽  
Band Structures ◽  
One Dimensional ◽  
Thermal Tuning

Phononic crystals make the realization of complete acoustic band gaps possible, which suggests many applications such as vibration isolation, noise suppression, acoustic barriers, filters, wave guides, and transducers. In this paper, an analytic model, based on the transfer matrix method, is developed to study the band structures of bulk acoustic waves including SH-, P-, and SV-waves in a one-dimensional phononic crystal, which is formed by alternating strips of two different materials. The analysis is demonstrated by the phononic crystal of Ba0.7Sr0.3TiO3 (BST) and polybutylene terephthalate (PBT), whose elastic properties depend strongly on the temperature. The results show that some band gaps are very sensitive to the temperature. Depending on the wave mode, the center frequency of the first band gap may decrease over 25% and band gap width may decrease over 60% as the temperature increases from 30 °C to 50 °C. The transmission of acoustic waves in a finite phononic crystal is also studied through the coefficient of transmission power. These results are very useful for the design and optimization of thermal tuning of phononic crystals.

Tunable Band Gaps of Acoustic Waves in Two-Dimensional Phononic Crystals With Reticular Band Structures

2009 ◽  
Author(s):  
Zi-Gui Huang ◽  
Yunn-Lin Hwang ◽  
Pei-Yu Wang ◽  
Yen-Chieh Mao
Keyword(s):  
Acoustic Waves ◽  
Composite Structures ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Sound Insulation ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Elastic Band ◽  
Band Structures ◽  
Elastic Band Gaps

The excellent applications and researches of so-called photonic crystals raise the exciting researches of phononic crystals. By the analogy between photon and phonon, repetitive composite structures that are made up of different elastic materials can also prevent elastic waves of some certain frequencies from passing by, i.e., the frequency band gap features also exist in acoustic waves. In this paper, we present the results of the tunable band gaps of acoustic waves in two-dimensional phononic crystals with reticular band structures using the finite element method. Band gaps variations of the bulk modes due to different thickness and angles of reticular band structures are calculated and discussed. The results show that the total elastic band gaps for mixed polarization modes can be enlarged or reduced by adjusting the orientation of the reticular band structures. The phenomena of band gaps of elastic or acoustic waves can potentially be utilized for vibration-free, high-precision mechanical systems, and sound insulation.

Full Band-Gap Silicon Phononic Crystals for Surface Acoustic Waves

2006 ◽  
Author(s):  
Saeed Mohammadi ◽  
Abdelkrim Khelif ◽  
Ryan Westafer ◽  
Eric Massey ◽  
William D. Hunt ◽  
...  
Keyword(s):  
Band Gap ◽  
Acoustic Waves ◽  
Phononic Crystal ◽  
Surface Acoustic Waves ◽  
Hexagonal Lattice ◽  
Phononic Crystals ◽  
Bulk Wave ◽  
Filling Fraction ◽  
Phononic Band Gap ◽  
Wide Range

Periodic elastic structures, called phononic crystals, show interesting frequency domain characteristics that can greatly influence the performance of acoustic and ultrasonic devices for several applications. Phononic crystals are acoustic counterparts of the extensively-investigated photonic crystals that are made by varying material properties periodically. Here we demonstrate the existence of phononic band-gaps for surface acoustic waves (SAWs) in a half-space of two dimensional phononic crystals consisting of hexagonal (honeycomb) arrangement of air cylinders in a crystalline Silicon background with low filling fraction. A theoretical calculation of band structure for bulk wave using finite element method is also achieved and shows that there is no complete phononic band gap in the case of the low filling fraction. Fabrication of the holes in Silicon is done by optical lithography and deep Silicon dry etching. In the experimental characterization, we have used slanted finger interdigitated transducers deposited on a thin layer of Zinc oxide (sputtered on top of the phononic crystal structure to excite elastic surface waves in Silicon) to cover a wide range of frequencies. We believe this to be the first reported demonstration of phononic band-gap for SAWs in a hexagonal lattice phononic crystal at such a high frequency.

Acoustic Waves in Two-Dimensional Phononic Crystals With Reticular Geometric Structures

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Zi-Gui Huang ◽  
Zheng-Yu Chen
Keyword(s):  
Band Gap ◽  
Acoustic Waves ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Sound Insulation ◽  
Two Dimensional ◽  
Elastic Band ◽  
Geometric Structures ◽  
2D And 3D ◽  
Elastic Band Gaps

Previous studies on photonic crystals raise the exciting topic of phononic crystals. This paper presents the results of tunable band gaps in the acoustic waves of two-dimensional phononic crystals with reticular geometric structures using the 2D and 3D finite element methods. This paper calculates and discusses the band gap variations of the bulk modes due to different sizes of reticular geometric structures. Results show that adjusting the orientation of the reticular geometric structures can increase or decrease the total elastic band gaps for mixed polarization modes. The band gap phenomena of elastic or acoustic waves can potentially be utilized to achieve vibration-free, high-precision mechanical systems, and sound insulation.

Surface Acoustic Wave Band Gaps and Phononic Structures on Thin Solid Plates

2005 ◽  
Author(s):  
Xinya Zhang ◽  
Ted Jackson ◽  
Emmanuel Lafound ◽  
Pierre Deymier ◽  
Jerome Vasseur
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Acoustic Waves ◽  
Phononic Crystal ◽  
Surface Acoustic Waves ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Laser Ultrasonics ◽  
Thin Plates ◽  
Wave Band

Novel phononic crystal structures on thin plates for material science applications in ultrasonic range (~ MHz) are described. Phononic crystals are created by a periodic arrangement of two or more materials displaying a strong contrast in their elastic properties and density. Because of the artificial periodic elastic structures of phononic crystals, there can exist frequency ranges in which waves cannot propagate, giving rise to phononic band gaps which are analogous to photonic band gaps for electromagnetic waves in the well-documented photonic crystals. In the past decades, the phononic structures and acoustic band gaps based on bulk materials have been researched in length. However few investigations have been performed on phononic structures on thin plates to form surface acoustic wave band gaps. In this presentation, we report a new approach: patterning two dimensional membranes to form phononic crystals, searching for specific acoustic transport properties and surface acoustic waves band gaps through a series of deliberate designs and experimental characterizations. The proposed phononic crystals are numerically simulated through a three-dimensional plane wave expansion (PWE) method and experimentally characterized by a laser ultrasonics instrument that has been developed in our laboratory.

Multifunctional One-dimensional Phononic Crystal Structures Exploiting Interfacial Acoustic Waves

2009 ◽  
Vol 1188 ◽  
Author(s):  
Albert C To ◽  
Bong Jae Lee
Keyword(s):  
Acoustic Waves ◽  
Filter Design ◽  
Phononic Crystal ◽  
Stop Band ◽  
Phononic Crystals ◽  
Thermal Barrier ◽  
Interfacial Wave ◽  
Lateral Direction ◽  
One Dimensional ◽  
Wave Filter

AbstractThe present study demonstrates that interfacial acoustic waves can be excited at the interface between two phononic crystals. The interfacial wave existing between two phononic crystals is the counterpart of the surface electromagnetic wave existing between two photonic crystals. While past works on phononic crystals exploit the unique bandgap phenomenon in periodic structures, the present work employs the Bloch wave in the stop band to excite interfacial waves that propagate along the interface and decay away from the interface. As a result, the proposed structure can be used as a wave filter as well as a thermal barrier. In wave filter design, for instance, the incident mechanical wave energy can be guided by the interfacial wave to the lateral direction; thus, its propagation into the depth is inhibited. Similarly, in thermal barrier design, incident phonons can be coupled with the interfacial acoustic wave, and the heat will be localized and eventually dissipated at the interface between two phononic crystals. Consequently, the thermal conductivity in the direction normal to the layers can be greatly reduced. The advantage of using two phononic crystals is that the interfacial wave can be excited even at normal incidence, which is critical in many engineering applications. Since the proposed concept is based on a one-dimensional periodic structure, the analysis, design, and fabrication are relatively simple compared to other higher dimensional material designs.

Propagation of Lamb Waves in Phononic-Crystal Plates

2007 ◽  
Vol 23 (3) ◽  
pp. 223-228 ◽  
Author(s):  
J.-C. Hsu ◽  
T.-T. Wu
Keyword(s):  
Band Gap ◽  
Triangular Lattice ◽  
Lamb Waves ◽  
Phononic Crystal ◽  
Plate Thickness ◽  
Expansion Method ◽  
Band Gaps ◽  
Square Lattice ◽  
Pass Band ◽  
Band Structures

AbstractIn this paper, the band structures of Lamb waves in the two-dimensional phononic-crystal plates are calculated and analyzed based on the plane wave expansion method. The phononic-crystal plates are composed of an array of circular crystalline iron cylinders embedded in the epoxy matrix. Square lattice and triangular lattice are analyzed and discussed, respectively. For the square lattice, two complete band gaps exist, and a narrow pass band between the complete band gaps separates them apart. For the triangular lattice, a wide complete band gap existing with the ratio of gap width to midgap frequency Δω/ωm equal to 72% is found. Furthermore, the influence of the plate thickness is crucial for band structures of Lamb waves. Tuning plate thickness can shift the pass bands effectively, and band shifting causes the variation of the width of complete band gap and its opening and closure.

The Study of Characteristics of Sphere-Radial Phononic Crystals

2011 ◽  
Vol 211-212 ◽  
pp. 609-614 ◽  
Author(s):  
Qi Hua Wen
Keyword(s):  
Phononic Crystal ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Practical Application ◽  
Elastic Wave Equation ◽  
Application Performance ◽  
One Dimensional ◽  
Simulation Results ◽  
The One ◽  
Attenuation Characteristics

By deducing the spherical elastic wave equation in theory, the concept of sphere-radial phononic crystal is proposed, and then the equations to determine the acoustic band structures is deduced. A numerical example is given for steel/nitrile rubber phononic crystal. The numerical simulation results suggest that the band gaps of sphere-radial phononic crystals do exist, which have better attenuation characteristics and practical application performance than the one-dimensional phononic crystals.

Attenuation Coefficients Prediction for Reflection Layers of Solidly Mounted Resonators via Phononic Band Structures

2008 ◽  
Author(s):  
Chien-Hou Liu ◽  
Yuan-Fang Chou
Keyword(s):  
Band Gap ◽  
Attenuation Coefficient ◽  
Periodic Structures ◽  
Characteristic Impedance ◽  
Phononic Crystal ◽  
Stop Band ◽  
Density Ratio ◽  
Phononic Crystals ◽  
Band Structures ◽  
Attenuation Coefficients

The solidly mounted resonator (SMR) is one of the major focuses in filter research because it can be used in the frequency above GHz range. The reflection structure composed of periodic layers is vital to the performance of this type of resonator due to its capability in confining acoustic energy in the piezoelectric layer. Therefore the design of reflection layers is a key issue in the development of SMRs. The performance of reflection layers is revealed by the attenuation coefficient that governs the energy distribution in the periodic structures. The behavior of waves propagate in the finite periodic structures are solved by transfer matrix method while the Hill’s method is employed to find the exact solutions in the corresponding phononic crystal. By comparing their displacement fields, it is observed that the attenuation coefficients of infinite and finite periodic structures are almost identical provided the number of layers is adequate. Therefore referring the design of reflection layers to the band structures of the corresponding phononic crystals is reasonable although the attenuation coefficient of a finite periodic structure can not be calculated directly. For one dimensional phononic crystals, the attenuation coefficient becomes larger as the first band gap gets wider. Moreover, the characteristic impedance ratio and density ratio between two interlaced materials increase simultaneously; the first band gap width also increases. This character can be adopted as a guideline in the design of solidly mounted resonators. Based on this guideline, Al and W are chosen as materials for the reflection structure. By calculating its electric impedance, the resonant frequency is found to be the same as the center frequency of first band gap of the corresponding phononic crystal. It shows that employing this stop band character to design the reflection structure of SMR is adequate and efficient.

TUNABLE BAND STRUCTURES OF 2D MULTI-ATOM ARCHIMEDEAN-LIKE PHONONIC CRYSTALS

2012 ◽  
Vol 01 (02) ◽  
pp. 1250016 ◽  
Author(s):  
Y. L. XU ◽  
C. Q. CHEN ◽  
X. G. TIAN
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Two Dimensional ◽  
Primitive Cell ◽  
The Finite Element Method ◽  
Band Structures ◽  
Solid System

Two dimensional multi-atom Archimedean-like phononic crystals (MAPCs) can be obtained by adding "atoms" at suitable positions in primitive cells of traditional simple lattices. Band structures of solid-solid and solid-air MAPCs are computed by the finite element method in conjunction with the Bloch theory. For the solid-solid system, our results show that the MAPCs can be suitably designed to split and shift band gaps of the corresponding traditional simple phononic crystal (i.e., with only one scatterer inside a primitive cell). For the solid-air system, the MAPCs have more and wider band gaps than the corresponding traditional simple phononic crystal. Numerical calculations for both solid-solid and solid-air MAPCs show that the band gap of traditional simple phononic crystal can be tuned by appropriately adding "atoms" into its primitive cell.

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