Acoustic, Underwater Cloak Makes Objects Invisible to Sonar
January 6, 2011 2:43 AM
comment(s) - last by
(Source: L. Brian Stauffer)
The cloak is used to control sound waves underwater
University of Illinois
researchers have developed a cloak that can be used underwater to hide objects from sonar and other ultrasound waves.
Nicholas Fang, study leader and mechanical science and engineering professor at the University of Illinois, along with fellow researchers at the university, have created an acoustic,
as a way of controlling sound waves.
Up until this point, scientists have been trying to push the use of materials that wrap sound around objects instead of absorbing or reflecting it. But turning the concept into a reality has been difficult.
Now, Fang and his team have made a prototype of a cloak that can make an object seem invisible to a variety of different sound waves.
"We are not talking about science fiction," said Fang. "We are talking about controlling sound waves by bending and twisting them in a designer space. This is certainly not some trick Harry Potter is playing with."
To make this cloak, researchers used metamaterial, which is a class of artificial materials that are engineered to have altered properties. The cloak is two-dimensional and cylindrical, and has 16 concentric rings of acoustic circuits, where each ring has a different index of refraction. This allows the cloak to help guide
and other ultrasound waves.
"Basically what you are looking at is an array of cavities that are connected by channels," said Fang. "The sound is going to propagate inside those channels, and the cavities are designed to slow the waves down. As you go further inside the rings, sound waves gain faster and faster speed."
tested the cloak on a steel cylinder
, among other objects with different shapes and sizes. The cloaked object was submerged underwater, and when sound wavelengths were transmitted, the sound waves would propagate around the cloak's outer rings and the acoustic circuits actually bent the waves so that they'd wrap around the outside of the cloak. Tests showed that cloak provided "acoustic invisibility" to sound waves from 40 to 80 KHz.
"This is not just a single wavelength effect," said Fang. "You don't have an invisible cloak that's showing up just by switching the frequencies slightly. The geometry is not theoretically scaled with wavelengths. The nice thing about the circuit element approach is that you can scale the channels down while maintaining the same wave propagation technology."
Fang and his group would like to see this cloak used as an aid for
, health care and soundproofing, but more research is needed to iron out a few kinks in the technology, such as formation and implosion of bubbles, called cavitation, in fast-moving underwater objects.
The paper can be found
This article is over a month old, voting and posting comments is disabled
If it doesn't reflect sound...
1/15/2011 11:35:20 AM
...won't the enemy sonar just have to look for the blank spot in the image, where no sound was returned? (To give a visual analogy, it'd be like being wrapped in a perfectly black material, that reflects no light. You'd see the big black spot easily.)
"I'm an Internet expert too. It's all right to wire the industrial zone only, but there are many problems if other regions of the North are wired." -- North Korean Supreme Commander Kim Jong-il
New Dolphin-Inspired Sonar Concept "Sees" Through Bubble Clouds
November 18, 2010, 10:36 AM
Improved Sonar and Stealth With The Same Nanotube?
June 14, 2010, 7:28 PM
Researcher Discovers New Cloaking Method
August 17, 2009, 10:11 AM
Latest By Tiffany Kaiser
Apple Racked Up 4 Million iPhone 6, iPhone 6 Plus Pre-orders Within 24 Hours
September 15, 2014, 9:54 AM
China to Require Real Names for Chat Apps
August 8, 2014, 8:28 PM
Quick Note: Windows Phone Store Surpasses 300,000 Apps
August 8, 2014, 12:30 PM
Google, Yahoo Working Together on Encrypted Email Tool
August 8, 2014, 7:23 AM
Edward Snowden's New Residence Permit Allows Another 3 Years in Russia
August 7, 2014, 2:41 PM
T-Mobile Beats Sprint in Prepaid Subscriber Numbers, John Legere Ribs New Sprint CEO
August 7, 2014, 11:55 AM
Microsoft Surface Losses Total $676M USD for FY2014; Will Launch in 25 Additional Markets
August 6, 2014, 1:07 PM
Quick Note: Microsoft Giving Nokia 630s to Employees Laid Off in China
August 6, 2014, 1:03 PM
Ten Apple Products Cut From China's Procurement List
August 6, 2014, 11:45 AM
Xiaomi Passes Samsung, Lenovo in China's Q2 Smartphone Shipments
August 5, 2014, 1:50 PM
Creationists are Mad About Google Doodle Depicting Evolution
November 24, 2015, 8:48 PM
DHS and TSA: Whoops, We Missed That 73 Airport Employees May be Terrorists
November 19, 2015, 2:16 PM
Star Wars Spinoff Film "Rogue One", Theme Park Attractions Announced
August 17, 2015, 12:20 PM
SpaceX Falcon 9's Seventh Supply Mission to ISS Ends w/ Fiery Stage 1 Explosion
June 28, 2015, 1:10 PM
Cool Science Video: Glowing Millipede Prowls the Nevada Desert
May 18, 2015, 12:00 PM
Newly Discovered Costa Rican Glass Frog is Kermit's Doppelgänger
April 22, 2015, 11:26 AM
Most Popular Articles
Free Windows 10 offer ends July 29th, 2016: 10 Reasons to Upgrade Immediately
July 22, 2016, 9:19 PM
Smart Security Cameras: 5 Good Choices For Any Budget
July 25, 2016, 7:13 PM
2017 Porsche Panamera: I’ll Take Three of These.
July 24, 2016, 6:44 PM
Top 5 Smart Watches
July 21, 2016, 11:48 PM
Latest Blog Posts
Sceptre Airs 27", 120 Hz. 1080p Monitor/HDTV w/ 5 ms Response Time for $220
Dec 3, 2014, 10:32 PM
Costco Gives Employees Thanksgiving Off; Wal-Mart Leads "Black Thursday" Charge
Oct 29, 2014, 9:57 PM
"Bear Selfies" Fad Could Turn Deadly, Warn Nevada Wildlife Officials
Oct 28, 2014, 12:00 PM
The Surface Mini That Was Never Released Gets "Hands On" Treatment
Sep 26, 2014, 8:22 AM
ISIS Imposes Ban on Teaching Evolution in Iraq
Sep 17, 2014, 5:22 PM
More Blog Posts
Copyright 2016 DailyTech LLC. -
Terms, Conditions & Privacy Information