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 SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

nachricht New survey hints at exotic origin for the Cold Spot
26.04.2017 | Royal Astronomical Society

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>