Bending and branching of acoustic waves in two-dimensional phononic crystals with linear defects

2005 ◽  
Vol 338 (3-5) ◽  
pp. 413-419 ◽  
Author(s):  
Xiaochun Li ◽  
Zhengyou Liu
Keyword(s):  
Acoustic Waves ◽  
Phononic Crystals ◽  
Two Dimensional ◽  
Linear Defects

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.

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.

Design and Fabrication of 2D Phononic Crystals in Surface Acoustic Wave Micro Devices

2005 ◽  
Author(s):  
Kebin Gu ◽  
Chien-Liu Chang ◽  
Jyh-Cherng Shieh
Keyword(s):  
Silicon Substrate ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Phononic Crystals ◽  
Two Dimensional ◽  
Central Frequency ◽  
Potential Applications ◽  
Specific Incident ◽  
Lift Off ◽  
Propagation Of Elastic Waves

In this paper, we present the design and fabrication of innovative phononic crystals integrated with two sets of interdigital (IDT) electrodes for frequency band selection of surface acoustic waves (SAW). The potential applications of this device include performance improvement of SAW micro-sensors, front-end components in RF circuitries, and directional receptions of high frequency acoustic waves. Analogous to the band-gap generated by photonic crystals, the phononic crystals, two dimensional repetitive structures composed of two different elastic materials, can prohibit the propagation of elastic waves with either specific incident angles or certain bandwidth. In this paper, the prohibited bandwidth has been verified by fabricating the phononic crystals between a micromachined SAW resonator and a receiver. Both the resonator and receiver are composed of IDT electrodes deposited and patterned on a thin piezoelectric layer. To confine the prohibited bandwidth on the order of hundred MHz, the diameter of the circular pores in phononic crystals is designed to be 6 micron and the aspect ratio of each pore is 3:1. To maximize the power transduction from IDT electrodes to SAW, the spacing between two inter-digits is one-fourth the wavelength of SAW. Specifically, the spacing ranges from 3.4 microns to 9.0 microns, depending on the central frequency. Both surface and bulk micromachining are employed and integrated to fabricate the crystals as well as SAW resonator and receiver altogether. Firstly, a 1.5-micron zinc oxide, which provides well-defined central frequency, is sputtered and patterned onto silicon substrate. Second, the IDT electrodes are evaporated and patterned by lift-off technique. Then the exposed silicon substrate is etched using DRIE to generate two dimensional phononic crystals. To tune the prohibited SAW bandwidth, the crystal pores are filled with copper or nickel by electroless plating. The insertion loss of the fabricated devices is characterized and is found to agree with simulation results.

Two-dimensional phononic crystals: surface acoustic waves

1999 ◽  
Vol 263-264 ◽  
pp. 77-80 ◽  
Author(s):  
Yukihiro Tanaka ◽  
Shin-ichiro Tamura
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Phononic Crystals ◽  
Two Dimensional

Multi-resonance tunneling of acoustic waves in two-dimensional locally-resonant phononic crystals

2017 ◽  
Vol 77 (2) ◽  
pp. 21101 ◽  
Author(s):  
Aichao Yang ◽  
Wei He ◽  
Jitao Zhang ◽  
Liang Zhu ◽  
Lingang Yu ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Phononic Crystals ◽  
Two Dimensional ◽  
Resonance Tunneling

Tuning the acoustic directional radiation by rotating square rods in two-dimensional phononic crystals

2014 ◽  
Vol 28 (23) ◽  
pp. 1450187 ◽  
Author(s):  
Jing Li ◽  
Fugen Wu ◽  
Huilin Zhong ◽  
Xin Zhang ◽  
Yuanwei Yao
Keyword(s):  
Cross Section ◽  
Acoustic Waves ◽  
Acoustic Propagation ◽  
Phononic Crystals ◽  
Contour Line ◽  
Two Dimensional ◽  
Radiation Frequency ◽  
Line Method ◽  
Directional Radiation ◽  
Wide Range

Analysis is given to acoustic directional radiation tuned by rotating square rods in two-dimensional (2D) solid–fluid phononic crystals (PC). The contour line method is introduced which predicts how the acoustic waves propagate at different frequency. As a specific example, for the systems of steel rods with square cross-section in a water host, we employ this approach to the analysis of the directivity successfully. The directional radiation frequency of two lowest bands are studied in this paper. The results show that the directional radiation frequency can be turned in a wide range by rotating the square rods. While the directivity of acoustic propagation keeps unchanged when the acoustic directional radiation frequency is located in the same band. Moreover, PCs exhibit excellent characteristic of single radiation branch as a corner cut off in a finite structure. Our approach may supply a new way to tune the directional radiation frequency.

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