Nav: Home

Chinese researchers achieve 3D underwater acoustic carpet cloak first with 'Black Panther'-like features

June 04, 2018

Cloaking is one of the most eye-catching technologies in sci-fi movies. In two 2018 Marvel films, Black Panther and Avengers: Infinity War, Black Panther conceals his country Wakanda, a technologically advanced African nation, from the outside world using the metal vibranium.

However, in the real world, if you want to hide something, you need to deceive not only the eyes, but also the ears, especially in the underwater environment.

Recently, a research team led by Prof. YANG Jun from the Institute of Acoustics (IOA) of the Chinese Academy of Sciences designed and fabricated a 3D underwater acoustic carpet cloak (UACC) using transformation acoustics.

The research was published online in Applied Physics Letters on June 1.

Like a shield, the carpet cloak is a material shell that can reflect waves as if the waves were reflecting off a planar surface. Hence, the cloaked target becomes undetectable to underwater detection instruments like sonar.

Using transformation acoustics, the research team first finished the 2D underwater acoustic carpet cloak with metamaterial last year (Scientific Reports, April 6, 2017). However, this structure works only in two dimensions, and becomes immediately detectable when a third dimension is introduced.

To solve this problem, YANG Jun and his IOA team combined transformation acoustics with a reasonable scaling factor, worked out the parameters, and redesigned the unit cell of the 2D cloak. They designed the 3D underwater acoustic carpet cloak and then proposed a fabrication and assembly method to manufacture it. The 3D cloak can hide an object from top to bottom and deal with complex situations, such as acoustic detection in all directions.

The 3D underwater acoustic carpet cloak is a pyramid comprising eight triangular pyramids; each triangular pyramid is composed of 92 steel strips using a rectangle lattice, similar to a wafer biscuit. More vividly, if we remove the core from a big solid pyramid, we can hide something safely in the hollow space left.

"To make a 3D underwater acoustic carpet cloak, researchers needed to construct the structure with 2D period, survey the influence of the unit cell's resonance, examine the camouflage effect at the ridge of the sample, and other problems. In addition, the fabrication and assembly of the 3D device required more elaborate design. The extension of the UACC from 2D to 3D represents important progress in applied physics,†said YANG.

In experimental tests, a short Gaussian pulse propagated towards the target covered with the carpet cloak, and the waves backscattered toward their origin. The cloaked object successfully mimicked the reflecting surface and was undetectable by sound detection. Meanwhile, the measured acoustic pressure fields from the vertical view demonstrated the effectiveness of the designed 3D structure in every direction.

"As the next step, we will try to make the 3D underwater acoustic carpet cloak smaller and lighter,†said YANG.

Funding for this research came from the National Natural Science Foundation of China (Grant No.11304351, 1177021304), the Youth Innovation Promotion Association of CAS (Grant No. 2017029), and the IACAS Young Elite Researcher Project (Grant No. QNYC201719).

Prof. YANG Jun and Dr. JIA Han led the research team from the Institute of Acoustics (IOA) of the Chinese Academy of Sciences. Prof. YANG Jun engages in research on sound, vibration and signal processing, and especially sound field control and array signal processing. They also work on other devices based on metamaterial in order to manipulate the propagation of sound waves.
-end-


Chinese Academy of Sciences Headquarters

Related Acoustics Articles:

Two-face god in sound: Directionality beyond spin-directed acoustics
Understanding unidirectional and topological wave phenomena requires the unveiling of intrinsic geometry and symmetry for wave dynamics.
Fish scattering sound waves has impact on aquaculture
Fisheries acoustics have been studied for over 40 years to assess biomass and optimize aquaculture applications, and researchers in France have examined the phenomenon of how fish scatter acoustic waves in a dense school of fish contained in an open-sea cage.
Can 3D-printing musical instruments produce better sound than traditional instruments?
Music is an art, but it is also a science involving vibrating reeds and strings, sound waves and resonances.
Finding meaning in 'Rick and Morty,' one burp at a time
One of the first things viewers of 'Rick and Morty' might notice about Rick is his penchant for punctuating his speech with burps.
Atom music lets listeners experience atomic world through sound
Atoms absorb and release energy in the form of photons that we perceive as different colors, which can be passed through a prism that reveals the atom's spectrum as colored lines.
Ultrasound techniques give warning signs of preterm births
Ultrasound can be used to examine cervix tissue and improve diagnostics, which is essential for predicting preterm births, and ultrasound data is used to compare two techniques for evaluating changes in cervical tissue throughout pregnancy.
Characterizing whale vocalization can help map migration
Killer whale pods each have their own set of calls they use to communicate, sometimes referred to as the pod's 'dialect.' By characterizing a pod's calls, researchers can track its seasonal movements, gaining a better understanding of the whales' lives.
Restaurant acoustics that schmeckt
Acoustics consultant Klaus Genuit says that new ISO guidelines for defining, measuring and evaluating soundscapes are a big step forward in guiding the creation of audibly fine restaurants.
How Nigerian music can help you choose a ripe watermelon
The quickest way to decide if a watermelon is ripe or not is by tapping on it.
How acoustics detected artillery in WWI
During WWI, William Lawrence Bragg led the development of an acoustic method to locate enemy artillery, work that was so successful that it was soon used widely throughout the British army.
More Acoustics News and Acoustics Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Making Amends
What makes a true apology? What does it mean to make amends for past mistakes? This hour, TED speakers explore how repairing the wrongs of the past is the first step toward healing for the future. Guests include historian and preservationist Brent Leggs, law professor Martha Minow, librarian Dawn Wacek, and playwright V (formerly Eve Ensler).
Now Playing: Science for the People

#566 Is Your Gut Leaking?
This week we're busting the human gut wide open with Dr. Alessio Fasano from the Center for Celiac Research and Treatment at Massachusetts General Hospital. Join host Anika Hazra for our discussion separating fact from fiction on the controversial topic of leaky gut syndrome. We cover everything from what causes a leaky gut to interpreting the results of a gut microbiome test! Related links: Center for Celiac Research and Treatment website and their YouTube channel
Now Playing: Radiolab

The Flag and the Fury
How do you actually make change in the world? For 126 years, Mississippi has had the Confederate battle flag on their state flag, and they were the last state in the nation where that emblem remained "officially" flying.  A few days ago, that flag came down. A few days before that, it coming down would have seemed impossible. We dive into the story behind this de-flagging: a journey involving a clash of histories, designs, families, and even cheerleading. This show is a collaboration with OSM Audio. Kiese Laymon's memoir Heavy is here. And the Hospitality Flag webpage is here.