Results 31 to 40 of about 183,094 (279)

Helmholtz-Structured Two-Dimensional Super-Diffraction Meta-Lens

Frontiers in Physics, 2022
Focusing beyond the acoustic diffraction limit has always been expected, especially in acoustic imaging and ultrasonic therapy. Manipulating the acoustic waves beyond the diffraction limit offers an alternative application potential in high-resolution ...
He-He Li, Bo Zheng, Mu-Sen Duan, Feng Han, Yun-Xin Hu, Xiao-You Li, Si-Yu Qian, Xue-Feng Chen, Sheng-Chun Liu   +8 more
doaj   +1 more source

Theoretical analysis of the focusing of acoustic waves by two-dimensional sonic crystals [PDF]

, 2002
Motivated by a recent experiment on acoustic lenses, we perform numerical calculations based on a multiple scattering technique to investigate the focusing of acoustic waves with sonic crystals formed by rigid cylinders in air.
Bikash C. Gupta, C. Rubio, D. Caballero, D. Caballero, E. Yablonovitch, E.R. Brown, E.R. Brown, E.R. Brown, F. Cervera, H. Kosaka, J. Martorell, J.C. Chen, J.P. Dowling, J.V. Sánchez-Pérez, L. Sanchis, M. Sigalas, M.S. Kushwaha, M.S. Kuswahs, P. Halevi, P. Halevi, P. Rigby, P.W. Evans, R. Martínez-Sala, S. Gupta, S.-Y. Lin, S.-Y. Lin, T.F. Krauss, T.F. Krauss, V. Twersky, W.M. Robertson, Y.Y. Chen, Y.Y. Chen, Zhen Ye   +32 more
core   +1 more source

Research Progress and Development Trends of Acoustic Metamaterials

Molecules, 2021
Acoustic metamaterials are materials with artificially designed structures, which have characteristics that surpass the behavior of natural materials, such as negative refraction, anomalous Doppler effect, plane focusing, etc.
Hao Song, Xiaodong Ding, Zixian Cui, Haohao Hu   +3 more
doaj   +1 more source

Sonic crystal lenses that obey Lensmaker's formula [PDF]

, 2003
This paper presents a theoretical study of the phenomenon of acoustic imaging by sonic crystals, which are made of two-dimensional regular arrays of rigid cylinders placed in parallel in air.
Beaver W L, Bloch F, Brillouin L, Brillouin L, Brillouin L, Caballero D, Chao-Hsien Kuo, Chen Y-Y, Dowling J P, Garcia N, Gupta B, Hecht E, Kushwaha M S, Martínez-Sala R, Medwin H, Robertson W M, Twersky V, Yariv A, Ye Z, Zhen Ye   +19 more
core   +1 more source

Broadband acoustic collimation and focusing using reduced aberration acoustic Luneburg lens [PDF]

Journal of Applied Physics, 2021
An acoustic Luneburg lens is a symmetric gradient-index lens with a refractive index decreasing radially from the center to the outer surface. It can be used to manipulate acoustic wave propagation allowing collimation and focusing capabilities. Previously studied acoustic Luneburg lenses based on the conventional Luneburg lens concept work only at ...
Liuxian Zhao, Timothy Horiuchi, Miao Yu
openaire   +2 more sources

Printing High Viscosity Fluids using Ultrasonic Droplet Generation [PDF]

, 2008
A new printing technology based on ultrasonic actuation (~1 MHz) is presented that has the potential to print high viscosity fluids. In this paper, we describe the print-head’s operating principles and construction.
Margolin, Lauren, Rosen, David W., Vohra, Sanjay   +2 more
core   +1 more source

Many-body effects in doped graphene on a piezoelectric substrate [PDF]

, 2017
We investigate the many-body properties of graphene on top of a piezoelectric substrate, focusing on the interaction between the graphene electrons and the piezoelectric acoustic phonons.
González, D. G., Guinea, F., Schiefele, J., Sols, F., Zapata, I.   +4 more
core   +3 more sources

Continuous-phase-transformation acoustic metasurface

Results in Physics, 2021
Acoustic metasurfaces are artificial structures, one of whose functions is to achieve plane wave focusing due to the phase gradient transformation of specific structural units. However, previous periodic acoustic metasurfaces for plane wave focusing have
Junfeng Chen, Jianlan Xie, Jianjun Liu
doaj   +1 more source

M-Bonacci Zone Plates for Ultrasound Focusing

Sensors, 2019
In this work, we present a thorough analysis on M-bonacci zone plates for ultrasound focusing applications. These planar lenses are capable of providing bifocal focusing profiles with equal intensity in both foci and become very appealing for a wide ...
Sergio Pérez-López, José Miguel Fuster, Pilar Candelas   +2 more
doaj   +1 more source

Linearly focused acoustic beams for acoustic microscopy

Electronics Letters, 1981
A linearly focused acoustic beam is investigated to be introduced into acoustic microscopy for characterising materials in the nonscanning version. The new acoustic beam enables us to detect acoustic anisotropies of materials to be measured successfully.
J. Kushibiki, A. Ohkubo, N. Chubachi
openaire   +1 more source