The World's First Acoustic Field Rotator, Described in Applied Physics Letters, May Help to Improve the Imaging Capabilities of Medical Ultrasound Devices
A Chinese-U.S. research team is exploring the use of metamaterials -- artificial materials engineered to have exotic properties not found in nature -- to create devices that manipulate sound in versatile and unprecedented ways.
In the journal Applied Physics Letters, the team reports a simple design for a device, called an acoustic field rotator, which can twist wave fronts inside it so that they appear to be propagating from another direction.
"Numerous research efforts have centered on metamaterial-based devices with fascinating wave-control capabilities such as invisibility or illusion cloaks," said Jian-chun Cheng, a professor at the Institute of Acoustics, in the Department of Physics at Nanjing University. "An acoustic field rotator, however, which can be [considered] a special kind of illusion cloak with the capability of making an object acoustically appear like a rotated one, doesn't exist yet."
Field rotators for electromagnetic waves and liquid waves have already been demonstrated and show promise in their respective areas, but "another important type of classical wave, an acoustic wave, is a much more familiar part of our daily lives and could find applications in a variety of situations," Cheng noted.
Cheng and colleagues designed what they believe to be the first feasible acoustic rotator model and also fabricated a prototype to validate it.
"We were surprised to discover that by using metamaterials, acoustic waves can be rotated in a manner similar to their electromagnetic or liquid wave counterparts -- so sound has finally joined the club," Cheng said.
Another surprise the team discovered was that acoustic and electromagnetic rotators can be designed based on the same principles. In this case, the researchers used anisotropic metamaterials, which possess physical properties that differ along different directions.
"It's much easier to implement highly anisotropic acoustic metamaterials than electromagnetic ones, and an acoustic rotator may provide even better performance than its [electromagnetic] counterparts," said Cheng.
The team hopes their acoustic rotator, with its ability to freely manipulate acoustic wavefronts, will improve the operation of devices like medical ultrasound machines, which require the precise control of acoustic waves. The ability to rotate the sound waves could improve the contrast of ultrasound devices and allow them to image damaged tissue or diagnose diseases in ways they currently cannot. This is significant because ultrasound devices may be cheaper than other imaging modalities and do not use X-rays.
What's ahead for the team now that they've shown the possibility of building an acoustic rotator by exploiting acoustic metamaterials? "We've fabricated the simplest proof-of-concept device, which at this point can't serve as a mature and practical device, so it's worth further improvement and optimization," said Cheng.
In the future, acoustic rotators could "serve as useful building blocks for constructing more complex structures with richer acoustic manipulation functionalities, if properly combined with other kinds of components," he added.
The article, "Broadband field rotator based on acoustic metamaterials" by Xue Jiang, Bin Liang, Xin-ye Zou, Lei-lei Yin, and Jian-chun Cheng appears in the journal Applied Physics Letters (DOI: 10.1063/1.4866333). The article will be published online on February 25, 2014. After that date, it can be accessed at: http://tinyurl.com/pv78pok
The authors of this paper are affiliated with Nanjing University, the Chinese Academy of Sciences and the University of Illinois at Urbana-Champaign.
ABOUT THE JOURNAL
Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology. See: http://apl.aip.org
Jason Socrates Bardi | newswise
Introducing the disposable laser
04.05.2016 | American Institute of Physics
New fabrication and thermo-optical tuning of whispering gallery microlasers
04.05.2016 | Okinawa Institute of Science and Technology (OIST) Graduate University
Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore.
Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly...
If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”
In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...
Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.
Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...
Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.
In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...
Honeycomb structures as the basic building block for industrial applications presented using holo pyramid
Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...
27.04.2016 | Event News
15.04.2016 | Event News
12.04.2016 | Event News
04.05.2016 | Physics and Astronomy
04.05.2016 | Physics and Astronomy
04.05.2016 | Materials Sciences