Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Space Industry and Business News .




TECH SPACE
Chameleon of the sea reveals its secrets
by Staff Writers
Boston MA (SPX) Feb 03, 2014


The cuttlefish, known as the "chameleon of the sea," can rapidly alter both the color and pattern of its skin. Researchers at Harvard and MBL now understand the biology and physics behind this process. Photo courtesy of Brian Gratwicke/Flickr, Creative Commons BY 2.0.

Scientists at Harvard University and the Marine Biological Laboratory (MBL) hope new understanding of the natural nanoscale photonic device that enables a small marine animal to dynamically change its colors will inspire improved protective camouflage for soldiers on the battlefield.

The cuttlefish, known as the "chameleon of the sea," can rapidly alter both the color and pattern of its skin, helping it blend in with its surroundings and avoid predators. In a paper published January 29 in the Journal of the Royal Society Interface, the Harvard-MBL team reports new details on the sophisticated biomolecular nanophotonic system underlying the cuttlefish's color-changing ways.

"Nature solved the riddle of adaptive camouflage a long time ago," said Kevin Kit Parker, Tarr Family Professor of Bioengineering and Applied Physics at the Harvard School of Engineering and Applied Sciences (SEAS) and core faculty member at the Wyss Institute for Biologically Inspired Engineering at Harvard. "Now the challenge is to reverse-engineer this system in a cost-efficient, synthetic system that is amenable to mass manufacturing."

In addition to textiles for military camouflage, the findings could also have applications in materials for paints, cosmetics, and consumer electronics.

The cuttlefish (Sepia officinalis) is a cephalopod, like squid and octopuses. Neurally controlled, pigmented organs called chromatophores allow it to change its appearance in response to visual clues, but scientists have had an incomplete understanding of the biological, chemical, and optical functions that make this adaptive coloration possible.

To regulate its color, the cuttlefish relies on a vertically arranged assembly of three optical components: the leucophore, a near-perfect light scatterer that reflects light uniformly over the entire visible spectrum; the iridophore, a reflector comprising a stack of thin films; and the chromatophore. This layering enables the skin of the animal to selectively absorb or reflect light of different colors, said coauthor Leila F. Deravi, a research associate in bioengineering at Harvard SEAS.

"Chromatophores were previously considered to be pigmentary organs that acted simply as selective color filters," Deravi said. "But our results suggest that they play a more complex role; they contain luminescent protein nanostructures that enable the cuttlefish to make quick and elaborate changes in its skin pigmentation."

When the cuttlefish actuates its coloration system, each chromatophore expands; the surface area can change as much as 500 percent. The Harvard-MBL team showed that within the chromatophore, tethered pigment granules regulate light through absorbance, reflection, and fluorescence, in effect functioning as nanoscale photonic elements, even as the chromatophore changes in size.

"The cuttlefish uses an ingenious approach to materials composition and structure, one that we have never employed in our engineered displays," said coauthor Evelyn Hu, Tarr-Coyne Professor of Applied Physics and of Electrical Engineering at SEAS. "It is extremely challenging for us to replicate the mechanisms that the cuttlefish uses.

"For example, we cannot yet engineer materials that have the elasticity to expand 500 times in surface area. And were we able to do so, the richness of color of the expanded and unexpanded material would be dramatically different-think of stretching and shrinking a balloon. The cuttlefish may have found a way to compensate for this change in richness of color by being an 'active' light emitter (fluorescent), not simply modulating light through passive reflection."

The team also included Roger Hanlon and his colleagues at the Marine Biological Laboratory in Woods Hole, Mass. Hanlon's lab has examined adaptive coloration in the cuttlefish and other invertebrates for many years.

"Cuttlefish skin is unique for its dynamic patterning and speed of change," Hanlon said. "Deciphering the relative roles of pigments and reflectors in soft, flexible skin is a key step to translating the principles of actuation to materials science and engineering. This collaborative project expanded our breadth of inquiry and uncovered several useful surprises, such as the tether system that connects the individual pigment granules."

For Parker, an Army reservist who completed two tours of duty in Afghanistan, using the cuttlefish to find a biologically inspired design for new types of military camouflage is more than an academic pursuit. He understands first-hand that poor camouflage patterns can cost lives on the battlefield.

"Throughout history, people have dreamed of having an 'invisible suit,'" Parker said. "Nature solved that problem, and now it's up to us to replicate this genius so, like the cuttlefish, we can avoid our predators."

In addition to Parker, Hu, Hanlon, and Deravi, the coauthors of the Interface paper are: Andrew P. Magyar, a former postdoctoral student in Hu's group; Sean P. Sheehy, a graduate student in Parker's group; and George R. R. Bell, Lydia M. Mathger, Stephen L. Senft, Trevor J. Wardill, and Alan M. Kuzirian, who all work with Hanlon in the Program in Sensory Physiology and Behavior at the Marine Biological Laboratory.

.


Related Links
Harvard University
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Microwires as mobile phone sensors
Gipuzkoa, Spain (SPX) Feb 03, 2014
Microwires were created in the former Soviet Union for military purposes. They formed the basis of the camouflage of a model of spy plane used by the Soviet army, but for a long time the scientific community has been studying them for other purposes. A study by the UPV/EHU's Magnetism Group is making progress in furthering understanding of the surface magnetic behaviour of glass-coated mic ... read more


TECH SPACE
Chameleon of the sea reveals its secrets

Quicker method paves the way for atomic-level design

Microwires as mobile phone sensors

Russia, US to join forces against space threats

TECH SPACE
GA-ASI and Northrop Showcase Unmanned Electronic Attack Capabilities

US Navy Accepts General Dynamics-built MUOS Ground Stations

Boeing Transmits Protected Government Signal Through Military Satellite

Boeing Transmits Protected Government Signal Through Military Satellite

TECH SPACE
45th Space Wing Supports NASA Launch

Athena-Fidus receives its "kick" for Arianespace's upcoming Ariane 5 launch

ILS Proton To Launch Yamal 601

Turkish Telecoms Satellite to Launch From Baikonur Feb. 15

TECH SPACE
Lockheed Martin Powers On Second GPS 3 Satellite In Production

India to launch three navigation satellites this year

NGC Wins Contract For GPS-Challenged Navigation and Geo-Registration Solution

20th Anniversary of Initial Operational Capability of the GPS Constellation

TECH SPACE
Launching the Fastest Plane of the Future

Red Arrows pilot killed by 'useless' seat mechanism

Swiss to vote in May on fighter deal

Boeing profits surge but tougher 2014 awaits

TECH SPACE
Dutch hi-tech group ASML profits dip despite record sales

2-proton bit controlled by a single copper atom

New Technique for Probing Subsurface Electronic Structure

Fastest organic transistor heralds new generation of see-through electronics

TECH SPACE
Savanna vegetation predictions best done by continent

Russian EVA re-attempting installation of Earth-observing cameras

NASA Set For A Big Year In Earth Science With Five New Missions

Signed, Sealed and Delivered: New NASA Video Shows GPM's Journey to Japan

TECH SPACE
Cooperative SO2 and NOx aerosol formation in haze pollution

Made in China for us: Air pollution tied to exports

Delhi says air 'not as bad' as Beijing after smog scrutiny

India's Essar sues Greenpeace for $80 mn for defamation




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement