Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Designing an Acoustic Diode

05.11.2013
Novel Design for a Device that Would Transmit Sound in One-way May Lead To Brighter, Clearer Ultrasound Images and Improve Diagnosis and Therapy

Most people know about ultrasound through its role in prenatal imaging: those grainy, grey outlines of junior constructed from reflected sound waves. A new technology called an "acoustic diode," envisioned by researchers in China's Nanjing University, may dramatically improve future ultrasound images by changing the way sound waves are transmitted.


Urbana/ B. Liang

Schematic illustration of “acoustic diode” made of a zero refractive-index medium (ZIM) prism, which only allows the acoustic waves comes from the left (“positive incidence”) to pass but blocks the waves from right (“negative incidence”).

In the journal Applied Physics Letters, which is produced by AIP Publishing, the scientists describe the theoretical framework for an acoustic diode -- a device that achieves a one-way transmission of sound waves much the same as an electrical diode controls the one-way transmission of electrical impulses.

The one-way flow of sound would provide brighter and clearer ultrasound images by eliminating acoustic disturbances caused by sound waves going in two directions at the same time and interfering with each other, explained researcher Jian-chun Cheng.

"The propagation direction of the output wave would be controlled freely and precisely," Cheng said. "These features are crucial for the medical ultrasound applications of the resulting devices."

How the Acoustic Diode Would Work

Sound waves easily flow in two directions. Yet in nature, total reflection of sound in one direction is known to occur at the air-water interface. This gave investigators the idea that an acoustical diode could be constructed by transmitting acoustic waves using an asymmetric prism to create total unidirectional reflection.

The team developed its theoretical model based on a material not found in nature called a near-Zero Index Metamaterial (ZIM) and a prism to create high transmission efficacy acoustic waves that strike a reflective boundary from two opposite sides.

In theory, explained Dr. Cheng, "This would produce a unique tunneling effect and an unprecedented property that the output waveform is kept consistent with those of the waves traveling toward a boundary. "

The article, "Unidirectional acoustic transmission through a prism with near-zero refractive index" by Yong Li, Bin Liang, Zhong-ming Gu, Xin-ye Zou and Jian-chun Cheng appears in the journal Applied Physics Letters. See: http://dx.doi.org/10.1063/1.4817249

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
Further information:
http://www.aip.org

More articles from Physics and Astronomy:

nachricht A better way to weigh millions of solitary stars
15.12.2017 | Vanderbilt University

nachricht A chip for environmental and health monitoring
15.12.2017 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>