scholarly journals An elastic fiber based on phononic crystals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Farzaneh Motaei ◽  
Ali Bahrami
Keyword(s):  
Crystal Structure ◽  
Elastic Waves ◽  
Acoustic Waves ◽  
Elastic Fiber ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Core Region ◽  
Crystal Fiber ◽  
The Core ◽  
First Time

AbstractIn this study, a novel elastic phononic crystal fiber has been presented for the first time. This proposed structure can expand the sonic communications field, significantly. In order to realize the elastic fiber performance, solid–solid phononic crystal has been utilized. The phononic crystal structure operates as cladding in surroundings and central region acts as core of fiber by elimination of rods. Incident acoustic waves with transverse polarization have confined and propagated in the core region of the phononic crystal fiber. Two types of phononic crystal fiber with different core radii have been investigated. Incident elastic waves can confine in the core region with confinement factor higher than 500. Also, longitudinal losses have been achieved low and equal to 0.35 dB/km.

scholarly journals Dual Photonic–Phononic Crystal Slot Nanobeam with Gradient Cavity for Liquid Sensing

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 421 ◽  
Author(s):  
Nan-Nong Huang ◽  
Yi-Cheng Chung ◽  
Hsiao-Ting Chiu ◽  
Jin-Chen Hsu ◽  
Yu-Feng Lin ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Acoustic Waves ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
The Finite Element Method ◽  
Concentrate Energy ◽  
Abrupt Changes ◽  
Analyte Solution ◽  
Liquid Sensing ◽  
Sensing Performance

A dual photonic–phononic crystal slot nanobeam with a gradient cavity for liquid sensing is proposed and analyzed using the finite-element method. Based on the photonic and phononic crystals with mode bandgaps, both optical and acoustic waves can be confined within the slot and holes to enhance interactions between sound/light and analyte solution. The incorporation of a gradient cavity can further concentrate energy in the cavity and reduce energy loss by avoiding abrupt changes in lattices. The newly designed sensor is aimed at determining both the refractive index and sound velocity of the analyte solution by utilizing optical and acoustic waves. The effect of the cavity gradient on the optical sensing performance of the nanobeam is thoroughly examined. By optimizing the design of the gradient cavity, the photonic–phononic sensor has significant sensing performances on the test of glucose solutions. The currently proposed device provides both optical and acoustic detections. The analyte can be cross-examined, which consequently will reduce the sample sensing uncertainty and increase the sensing precision.

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.

Research on the large band gaps in multilayer radial phononic crystal structure

2016 ◽  
Vol 30 (10) ◽  
pp. 1650108 ◽  
Author(s):  
Nansha Gao ◽  
Jiu Hui Wu ◽  
Dong Guan
Keyword(s):  
Crystal Structure ◽  
Finite Element Method ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Transmission Spectra ◽  
Intermediate Mass ◽  
Displacement Fields ◽  
Vibration Coupling ◽  
Single Material

In this paper, we study the band gaps (BGs) of new proposed radial phononic crystal (RPC) structure composed of multilayer sections. The band structure, transmission spectra and eigenmode displacement fields of the multilayer RPC are calculated by using finite element method (FEM). Due to the vibration coupling effects between thin circular plate and intermediate mass, the RPC structure can exhibit large BGs, which can be effectively shifted by changing the different geometry values. This study shows that multilayer RPC can unfold larger and lower BGs than traditional phononic crystals (PCs) and RPC can be composed of single material.

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.

One-way transmission and mode conversion of elastic waves by a hybrid phononic crystal structure

2019 ◽  
Vol 125 (21) ◽  
pp. 215101 ◽  
Author(s):  
Ji-En Wu ◽  
Ruixia Hu ◽  
Bing Tang ◽  
Xiaoyun Wang ◽  
Han Jia ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Elastic Waves ◽  
Mode Conversion ◽  
Phononic Crystal

DETECTION AND DISCRIMINATION BETWEEN ALPHA PARTICLES AND PROTONS BASED ON PHONONIC CRYSTALS MATERIALS

2019 ◽  
Vol 26 (07) ◽  
pp. 1850219 ◽  
Author(s):  
AHMED MEHANEY ◽  
MOSTAFA F. EISSA ◽  
ARAFA H. ALY
Keyword(s):  
Polymethyl Methacrylate ◽  
Alpha Particle ◽  
Elastic Waves ◽  
Incident Energy ◽  
High Probability ◽  
Radiation Detector ◽  
Thin Sheet ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Alpha Particles

Ionizing particles detection based on phonons counting are considered as a growing research point of great interest. Phononic crystal (PnC) detectors have a higher resolution than other detectors. In the present work, we shall prepare a setup of a radiation detector based on a 1D PnC. The PnC detector can be used in detection and discrimination between protons and alpha particles with incident energy 1[Formula: see text]MeV. We have proposed a model capable of filtering the energies of two different ionizing particles (proton and alpha particle) of specific lattice frequencies in steps. Firstly, the high probability of phonons production was found at transmitted energy 5[Formula: see text]KeV from the whole path of protons and alpha particles through a vertical thin sheet made from Mylar and Polymethyl methacrylate (PMMA), respectively. The outgoing elastic waves are subjected to propagate through the proposed PnCs structure (Teflon-Polyethylene)2 that shows the different transmission percentage to each particle. Therefore, the detection and discrimination between ionizing ions were achieved.

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