Featured Research

from universities, journals, and other organizations

Genetic approach helps design broadband metamaterial

Date:
May 5, 2014
Source:
Penn State
Summary:
A specially formed material that can provide custom broadband absorption in the infrared can be identified and manufactured using 'genetic algorithms,' according to engineers who say these metamaterials can shield objects from view by infrared sensors, protect instruments and be manufactured to cover a variety of wavelengths.

(L) Drawing of the metamaterial absorber pattern. (R) Actual metamaterial absorber pattern
Credit: Bossard/Penn State

A specially formed material that can provide custom broadband absorption in the infrared can be identified and manufactured using "genetic algorithms," according to Penn State engineers, who say these metamaterials can shield objects from view by infrared sensors, protect instruments and be manufactured to cover a variety of wavelengths.

Related Articles


"The metamaterial has a high absorption overbroad bandwidth," said Jeremy A. Bossard, postdoctoral fellow in electrical engineering. "Other screens have been developed for a narrow bandwidth, but this is the first that can cover a super-octave bandwidth in the infrared spectrum."

Having a broader bandwidth means that one material can protect against electromagnetic radiation over a wide range of wavelengths, making the material more useful. The researchers looked at silver, gold and palladium, but found that palladium provided better bandwidth coverage. This new metamaterial is actually made of layers on a silicon substrate or base. The first layer is palladium, followed by a polyimide layer. On top of this plastic layer is a palladium screen layer. The screen has elaborate, complicated cutouts -- sub-wavelength geometry -- that serve to block the various wavelengths. A polyimide layer caps the whole absorber.

"As long as the properly designed pattern in the screen is much smaller than the wavelength, the material can work effectively as an absorber," said Lan Lin,graduate student in electrical engineering. "It can also absorb 90 percent of the infrared radiation that comes in at up to a 55 degree angle to the screen."

To design the necessary screen for this metamaterial, the researchers used a genetic algorithm. They described the screen pattern by a series of zeros and ones -- a chromosome -- and let the algorithm randomly select patterns to create an initial population of candidate designs. The algorithm then tested the patterns and eliminated all but the best. The best patterns were then randomly tweaked for the second generation. Again the algorithm discarded the worst and kept the best. After a number of generations the good patterns met and even exceeded the design goals. Along the way the best pattern from each generation was retained. They report their results in a recent issue of ACSNano.

"We wouldn't be able to get an octave bandwidth coverage without the genetic algorithm," said Bossard. "In the past, researchers have tried to cover the bandwidth using multiple layers, but multiple layers were difficult to manufacture and register properly."

This evolved metamaterial can be easily manufactured because it is simply layers of metal or plastic that do not need complex alignment. The clear cap of polyimide serves to protect the screen, but also helps reduce any impedance mismatch that might occur when the wave moves from the air into the device.

"Genetic algorithms are used in electromagnetics, but we are at the forefront of using this method to design metamaterials," said Bossard.

Other researchers on this project included Seokho Yun, former postdoctoral fellow in electrical engineering, Liu Liu,graduate student in electrical engineering, Douglas H. Werner, McCain Chair Professor of Electrical Engineering, and Theresa Meyer, Distinguished Professor of Electrical Engineering and Materials Science and Engineering, all at Penn State.


Story Source:

The above story is based on materials provided by Penn State. The original article was written by A'ndrea Elyse Messer. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jeremy A. Bossard, Lan Lin, Seokho Yun, Liu Liu, Douglas H. Werner, Theresa S. Mayer. Near-Ideal Optical Metamaterial Absorbers with Super-Octave Bandwidth. ACS Nano, 2014; 8 (2): 1517 DOI: 10.1021/nn4057148

Cite This Page:

Penn State. "Genetic approach helps design broadband metamaterial." ScienceDaily. ScienceDaily, 5 May 2014. <www.sciencedaily.com/releases/2014/05/140505112538.htm>.
Penn State. (2014, May 5). Genetic approach helps design broadband metamaterial. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2014/05/140505112538.htm
Penn State. "Genetic approach helps design broadband metamaterial." ScienceDaily. www.sciencedaily.com/releases/2014/05/140505112538.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Who Will Failed Nuclear Talks Hurt Most?

Who Will Failed Nuclear Talks Hurt Most?

Reuters - Business Video Online (Nov. 25, 2014) With no immediate prospect of sanctions relief for Iran, and no solid progress in negotiations with the West over the country's nuclear programme, Ciara Lee asks why talks have still not produced results and what a resolution would mean for both parties. Video provided by Reuters
Powered by NewsLook.com
Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Reuters - Innovations Video Online (Nov. 25, 2014) A virtual flying enthusiast converts parts of a written-off Airbus aircraft into a working flight simulator in his northern Slovenian home. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Newsy (Nov. 23, 2014) Microsoft has robotic security guards working at its Silicon Valley Campus. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins