Scientific Frontline® On-Site Search Engine by Google Co-op

Current UTC Time
News Home, where you will find the "Current Top Stories"The Communication Center contains current news briefs from major Universities, NASA, ESA, and the top three Aviation Mfg.Science section contains all the latest knowledge in Medical Research, Archeology, Biology, and other General Science NewsCurrent Earth Science and Environmental discoveries.The E.A.R., Environmental Awareness Report. E.A.R. will keep you advised of Environmental Alerts, Government, University, and public projects. All the current space discoveries from Hubble, Spitzer, Chandra X-Ray, ESO, Gemini, Subaru, ESA, NASA, and many more. The latest in space theories from leading astronomers and scientist from around the world.The Space Weather Forecast Center by Scientific Frontline, Current up-to-date space weather, forecasts, alerts and warnings. Images from SOHO, GOES, and STEREO. Plus solar observations from Erika RixCurrent space missions newsThe Cassini Main Page. Containing all the latest news from the Cassini Spacecraft around Saturn. Leading into Cassini status reports, The Cassini Gallery of all the latest images from Cassini. Seeing Saturn and all her moons like never before.Daily Sky maps, Celestial Events Calendar.Observatories Gallery, images from The Great Observatories and other leaders in astronomy.The Stellar Nights  Gallery, An amateur astronomical collection from John Crilly, Richard Handy, Erika Rix, and Paul RixCloudy Nights Telescope Reviews / An Atronomical Community.The latest in Computer, Nanotechnology, and General Technological advancements.The latest in Aviation achievements in civil, military, and space aviationThe World News Report,  news from the Voxant Viral Syndication, known as the Newsroom. Contains the latest videos from major news sources.The news archive from Scientific Frontline's past articles. A world of knowledge at your fingertips.Abstracts, Journals, and Technical papers maintained by Scientific Frontline. The Gateway to all the galleries in the Scientific Frontline collectionThe Scientific Frontline IYA 2009 CoverageResearch Department | Staff and Researchers OnlySite Related links from major universities, government and private research labs.Assorted Downloads related to space, science, aviation, including screensavers and ASTROMONY SOFTWARE, and other endorsed programs.Words from Heidi-Ann Kennedy, Director Scientific FrontlineThe foundation of an online publication by SFL ORG. News Network called Scientific FrontlineContact page to Scientific Frontline / SFL ORG. News NetworkDisclaimer / Legal Notice for use of the SFL ORG. News Network's publication Scientific Frontline
an online publication of the SFL ORG. Educational News Network

Sandia research points way toward chameleon-like camouflage

Tuesday, April 7, 2009

Certain fish species blend with their environment by changing color.

Real-life video of rings forming and disbanding
Image Caption
Low-Res Image | Hi-Res Image
Sandia researcher George Bachand examines an enlargement of actual images of light-emitting quantum dots. These ride microtubules that have spontaneously formed stable circles of about 5 microns diameter. The picture superimposes two separate images – one of green rings and one of red – for visual effect. The images were processed to remove noise and maximize contrast.

Video Credit: Sandia National Laboratories
Image Credit: Randy Montoya / Sandia National Laboratories
Sandia National Laboratories researchers have demonstrated that, in theory, they could cause synthetic materials to change color like fish do.

Camouflage outfits that blend with a variety of environments without need of an outside power source — say, blue when at sea and then brown in a desert environment — is where this work could eventually lead,” says principal investigator George Bachand. “Or the same effect could be used in fabricating chic civilian clothing that automatically changes color to fit different visual settings.”

Such clothing could be a reality in five to ten years, he says.

The power source for both the biological and the lab method relies on the basic cellular fuel called ATP, which releases energy as it breaks down. Fifty percent (roughly) is absorbed by the motor proteins — tiny molecular motors able to move along surfaces.

When fish change colors, motor proteins aggregate and disperse skin pigment crystals carried in their “tails” as they walk with their “feet” along the microtubule skeleton of the cell. By this means, they rearrange the color display.

Introducing an on/off switch

To put motor proteins in motion or switch them off, nature uses complex signaling networks. The Bachand group’s method is simpler. It involves the simple genetic insertion of a kind of docking port in the motor protein’s structure. What docks are zinc ions. Bound zinc ions turn the protein’s action to “off.” Stripping zinc ions out with chemical agents allows the motor protein to work again. The effect is controllable, and even reversible.

We essentially reengineered the protein structure to introduce a switch into the motor,” says Bachand. “So we can now turn our nanofluidic devices on and off.”

Previous efforts at regulating motor activity have used fuel intake as a control mechanism: the less the fuel, the slower the process. The Bachand group’s switch, operated independently of fuel changes, resembles the improvement in early automobile technologies when a simple ignition switch took over for more complicated rheostats. The paper describing this work was a spotlighted article in the journal Biotechnology and Bioengineering.

But what is it that the switch operates?

Like crowd surfers at a rock concert

In a cover article in the high-profile journal Advanced Materials (Dec. 2, 2008), the Sandia team describes a kind of inverted cellular world, where motor proteins do not run about but instead are upended so that their tails are embedded in a protein-modified layer on a glass slide. Free-ranging microtubules — cylindrical protein filaments — instead of forming the cellular skeleton of cells, are passed along by the waving feet of the motor proteins like crowd surfers at a rock concert, or like buckets passed hand-to-hand along a line of firefighters.

The traveling microtubules are coated with quantum dots — nanoscopic groups of atoms that emit light, their frequency dependent on dot size.

The dots emit different frequency of light than they adsorb, while the biological system merely reflects incoming wavelengths. But they perform similar coloring functions.

The telephone cord twist

When motor-transported microtubules collide, the microtubules stick together and twist until they resemble a desk phone cord. The twisting process ultimately forces the formation of stable rings approximately five micrometers in diameter. Their docked quantum dots (cadmium selenide) produce a range of light frequencies.

When mechanical strain in the rings causes them to rupture, the cracked segments are tugged out by the nearby motors until the ring is completely disassembled. The formation and destruction of the two states — free microtubules and rings — can be reversibly controlled.

Thus the dots can be tightly packed or dispersed — optically, an essential ingredient in the perception of color change.

Mimicking fish

The process resembles the action of fish color changes, which require one group of motor proteins carrying pigments to be “on” all the time while a second group of motor proteins is turned on by complex biological processes at the right time. This produces a tug-of-war between motor groups that results in pigment dispersion and ultimately a color change. When the second motor is switched off, the color returns to the ground aggregate state.

Our overall process mimics the fish,” says Bachand. “We essentially go from a dispersed particle state to a concentrated one and then back again to dispersed, similar to the fish. Thus, in principle, the mechanism could produce a color change. The underlying science provides a new basis for materials scientists to begin working toward real-world applications.”

The work was supported by DOE Basic Energy Sciences and Sandia’s Laboratory Directed Research & Development office.

Key contributors to the Biotechnology & Bioengineering paper were Adrienne Greene and Amanda Trent (now a graduate student at University of California, Santa Barbara). Advanced Materials paper contributors were Haiqing Liu (now at Los Alamos National Laboratory), Erik Spoerke, Marlene Bachand, Steve Koch (former Sandia employee, now an assistant professor at the University of New Mexico), and Bruce Bunker.

Source: Sandia National Laboratories

AddThis Social Bookmark Button

Scientific Frontline®
RSS Feeds

Scientific Frontline®
The Comm Center
The E.A.R.®
World News Report
Stellar Nights®
Cassini Gallery
Mars Gallery
Missions Gallery
Observatories Gallery
Observatories Gallery
Space Weather Alerts
Directors Chair

Scientific Frontline®
Is supported in part by
Readers Like You”
Sandia’s diamond-like films on board NASA satellite Scientists Detect 'Fingerprint' of High-Temp Superconductivity Above Transition Temperature Quantum Dots Pose Minimal Impact to Cells Navigate Back or Forward Through Technology News, Related Page or Pick an Article From The News Ticker.

Scientific Frontline®, Stellar Nights®, E.A.R.®, and Environmental Awareness Report®”
Are Registered Trademarks of the
Online Publication of the SFL ORG. Educational News Network
Oklahoma City, Oklahoma USA
A Not-for-Profit Educational News Service
© 2005 - 2009 All Rights Reserved

Home | Comm. Center | Science | Earth Science | Space | Space Weather Center | Aviation | Technology | Galleries | About Us | Contact Us | Site Map | FAQ