UC Berkeley researchers borrow principles of resonance to develop a new material that captures a sound waves fine details
Using the same principles that help create a guitars complex tones, researchers at the University of California, Berkeley, have developed a new material that holds promise for revolutionizing the field of ultrasound imaging.
The substance, dubbed an "ultrasonic metamaterial," responds differently to sound waves than any substance found in nature. Within a decade, the researchers report, the technology they developed to create the material could be used to vastly enhance image resolution of ultrasound, while at the same time allowing for the miniaturization of acoustic devices at any given frequency.
"Basically, the resonators work together, supporting a much higher modulation of the acoustic wave," Fang said. "They are reacting as a very precise ruler, allowing us to measure the finer features of the wave."
This ability provides the basis for the materials usefulness in ultrasound imaging. One of the factors limiting resolution quality of sonograms is the ability of the ultrasound lens to capture sound waves. Currently, these lenses are made with elastic materials such as polymers. The elasticity of the materials is what allows them to capture and focus the waves. But there is a limit to the finest resolution that they can capture.
"With this new material with a negative modulus, all the limits can be overcome," Fang said.
The material that Zhangs research group fabricated is 55 centimeters long and houses 60 resonators. In its present form, it can be used only for one frequency and can capture sound from only one direction. The groups plan, said Zhang, is to develop "three-dimensional" materials that will not only be able to capture sound from every direction, but will also be tunable. That is, the size of the resonators will be adjustable so that the material can respond to any frequency. Once they have designed and tested such a material, Zhang expects to be able to use microfabrication techniques to build materials with hundreds of thousands of resonators.
Because its resonators are many times smaller than wavelengths of the sound wave, Zhang said, the material can be used to make compact sonar and ultrasonic devices. Conventional lenses in these devices must be at least as large as the waves they are meant to capture. Sonar devices, which use long-length waves, would particularly benefit from this miniaturization.
The other researchers who contributed to the study are Dongjuan Xi, a former graduate student of Zhangs; Jianyi Xu, a visiting scholar from Nanjing University, who was a member of Zhangs lab when the work was conducted; and Muralidhar Ambati and Werayut Srituravanich, Ph.D. students of Zhangs.
Liese Greensfelder | EurekAlert!
Meter-sized single-crystal graphene growth becomes possible
22.08.2017 | Science China Press
Nagoya physicists resolve long-standing mystery of structure-less transition
21.08.2017 | Nagoya University
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Health and Medicine
22.08.2017 | Materials Sciences
22.08.2017 | Life Sciences