2010-08-29

Electricity collected from the air

Scheme to 'pull electricity from the air' sparks debate


Tiny charges gathered directly from humid air could be harnessed to generate electricity, researchers say. 

Dr Fernando Galembeck told the American Chemical Society meeting in Boston that the technique exploited a little-known atmospheric effect.

Tests had shown that metals could be used to gather the charges, he said, opening up a potential energy source in humid climates.

However, experts disagree about the mechanism and the scale of the effect.

"The basic idea is that when you have any solid or liquid in a humid environment, you have absorption of water at the surface," Dr Galembeck, from the University of Campinas in Brazil, told BBC News.


Electricity collected from the air could become the newest alternative energy source


Scientists once believed that water droplets in the atmosphere were electrically neutral, and remained so even after coming into contact with the electrical charges on dust particles and droplets of other liquids. But new evidence suggested that water in the atmosphere really does pick up an electrical charge.

Galembeck and colleagues confirmed that idea, using laboratory experiments that simulated water’s contact with dust particles in the air. They used tiny particles of silica and aluminum phosphate, both common airborne substances, showing that silica became more negatively charged in the presence of high humidity and aluminum phosphate became more positively charged. High humidity means high levels of water vapor in the air ― the vapor that condenses and becomes visible as “fog” on windows of air-conditioned cars and buildings on steamy summer days.

“This was clear evidence that water in the atmosphere can accumulate electrical charges and transfer them to other materials it comes into contact with,” Galembeck explained. “We are calling this ‘hygroelectricity’, meaning ‘humidity electricity’.”


Langmuir

Charge Partitioning at Gas−Solid Interfaces: Humidity Causes Electricity Buildup on Metals

Telma R. D. Ducati, Lus H. Simes and Fernando Galembeck*
Institute of Chemistry, University of Campinas, Campinas SP, Brazil 13083-970



Home » Formas de Apoio » Pesquisa para Inovação » PFPMCG

Professor Fernando Galembeck

Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154 – 13084-971 – Campinas – Brazil




Sources
BBC News - Scheme to 'pull electricity from the air' sparks debate
http://www.bbc.co.uk/news/technology-11100528
Electricity collected from the air could become the newest alternative energy source
http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_ARTICLEMAIN&node_id=222&content_id=CNBP_025407&use_sec=true&sec_url_var=region1&__uuid=f899de81-a3fe-49a3-ae8c-f505ad2aab37
Charge Partitioning at Gas−Solid Interfaces: Humidity Causes Electricity Buildup on Metals - Langmuir (ACS Publications)
http://pubs.acs.org/doi/abs/10.1021/la102494k
:: FAPESP :: - PFPMCG - Professor Fernando Galembeck
http://www.fapesp.br/materia/5057/pfpmcg/professor-fernando-galembeck.htm

Related
Can we grab electricity from muggy air? - tech - 26 August 2010 - New Scientist
http://www.newscientist.com/article/dn19367-can-we-grab-electricity-from-muggy-air.html
Electricity collected from the air could become the newest alternative energy source
http://www.physorg.com/news201958072.html
Scientists hope to collect electricity from the air
http://www.gizmag.com/harnessing-electricity-from-the-air/16137/
Pesquisa FAPESP Online
http://revistapesquisa.fapesp.br/?art=2428&bd=1&pg=1&lg=en
Brazil groups sees 'hygroelectricity' as new renewable power source, lightning preventer |
http://ceramics.org/ceramictechtoday/materials-innovations/brazil-groups-sees-hygroelectricity-as-new-renewable-power-source-lightning-preventer/
Energy source of the future: electricity from the air - SmartPlanet
http://www.smartplanet.com/business/blog/smart-takes/energy-source-of-the-future-electricity-from-the-air/10156/

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2010-08-27

Stanford's Gecko-like 'Stickybot Climbs Vertical Surfaces

Scaling buildings like Spiderman could be a reality, scientists claim

Walking up the side of buildings like Spiderman could soon be a reality, scientists have claimed.

Stanford researchers Paul Day (L) and Alan Asbeck with the Stickybot

Technicians have struggled over the last 10 years to create an artificial version strong enough for a vertical climb to be attempted successfully. However, researchers at Stanford University, California, have created a rubber-like material covered with thousands of tiny polymer fibres to imitate the gecko's hairs. These hairs, which are called setae, are ten times thinner than a human hair.

The material is said to be strong and reusable, and leaves no residue or damage. It has been tested on a "robotic gecko" called Stickybot which can walk up panes of glass.





Stanford University

Secrets of the gecko foot help robot climb

The science behind gecko toes holds the answer to a dry adhesive that provides an ideal grip for robot feet. Stanford mechanical engineer Mark Cutkosky is using the new material, based on the structure of a gecko foot, to keep his robots climbing.

Wonders of the gecko toe

The toe of a gecko's foot contains hundreds of flap-like ridges called lamellae. On each ridge are millions of hairs called setae, which are 10 times thinner than a human's. Under a microscope, you can see that each hair divides into smaller strands called spatulae, making it look like a bundle of split ends. These split ends are so tiny (a few hundred nanometers) that they interact with the molecules of the climbing surface.
The interaction between the molecules of gecko toe hair and the wall is a molecular attraction called van der Waals force. A gecko can hang and support its whole weight on one toe by placing it on the glass and then pulling it back. It only sticks when you pull in one direction – their toes are a kind of one-way adhesive, Cutkosky said.

"It's very different from Scotch tape or duct tape, where, if you press it on, you then have to peel it off. You can lightly brush a directional adhesive against the surface and then pull in a certain direction, and it sticks itself. But if you pull in a different direction, it comes right off without any effort," he said.




StickyBot


stalks_bent.jpg Microscope video of version 1 stalks attaching to a thin strip without normal preload.

For the latest hierarchical directional materials see ClimbingAdhesion .

Key Ideas:

Stickybot is an embodiment of our hypotheses about the requirements for mobility on vertical surfaces using dry adhesion. The main point is that we need controllable adhesion. The essential ingredients are:
  • hierarchical compliance for conforming at centimeter, millimeter and micrometer scales,
  • anisotropic dry adhesive materials and structures so that we can control adhesion by controlling shear,
  • distributed active force control that works with compliance and anisotropy to achieve stability.
Collected from: StickyBot < Rise < TWiki


Sources
Scaling buildings like Spiderman could be a reality, scientists claim - Telegraph
http://www.telegraph.co.uk/science/science-news/7963830/Scaling-buildings-like-Spiderman-could-be-a-reality-scientists-claim.html
Video - Breaking News Videos from CNN.com - Geckos inspire 'Stickybots'
http://edition.cnn.com/video/data/2.0/video/tech/2010/07/28/eod.tuchman.sticky.bot.cnn.html
Secrets of the gecko foot help robot climb
http://news.stanford.edu/news/2010/august/gecko-082410.html
YouTube - Stanford's 'Stickybot,' a Gecko-like robot, climbs vertical services
http://www.youtube.com/watch?v=o5lMJtQOKSY&feature=player_embedded#!
StickyBot < Rise < TWiki
http://bdml.stanford.edu/twiki/bin/view/Rise/StickyBot?redirectedfrom=Main.StickyBot
YouTube - Stanford StickyBot
http://www.youtube.com/watch?v=odAifbpDbhs

Related
StickyBotIII < Rise < TWiki
http://bdml.stanford.edu/twiki/bin/view/Rise/StickyBotIII
Gecko's hairy toes inspire climbing robot
http://www.wired.co.uk/news/archive/2010-08/26/gecko-robot
Stanford Robotics @ NRW: Stickybot III | BotJunkie
http://www.botjunkie.com/2010/04/15/stanford-robotics-nrw-stickybot-iii/

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2010-08-26

American Science and Engineering Z Backscatter Van™ (ZBV) Mobile Screening System


American Science and Engineering’s Z Backscatter Van (ZBV) is a low-cost, extremely maneuverable screening system built into a commercially available delivery van. The ZBV employs AS&E’s patented Z Backscatter technology, which offers photo-like images that reveal contraband that transmission X-rays miss – such as explosives (including car bombs), people and plastic weapons – and provides photo-like imaging for rapid analysis.

 ZBV in action


Z Backscatter: power, effectiveness and safety

The ABCs of Z

Proprietary Z Backscatter technology provides the highest clarity, photo-like images available, allowing accurate and rapid interpretation — unachievable with traditional transmission X-ray images alone.
Z Backscatter is AS&E's signature X-ray technology. Made possible by AS&E's patented Flying Spot, this technology is protected by more than 20 patents and is the proven approach for the discrimination of organic or "low Z" (i.e., low atomic number) materials such as explosives, drugs, cigarettes, and people, especially when hidden within a complex environment. [...]

The Compton Scattering Effect

AS&E's Z Backscatter inspection systems use electronically generated X-rays to examine an object. When X-rays interact with matter, they generally do one of three things:
  1. They pass through the object.
  2. They are absorbed by the object.
  3. They are scattered from the object.
Objects with greater density block or absorb more X-rays than objects with lesser density. These dense objects produce the characteristic shadow-like images similar to medical X-rays. These shadowgrams are produced by transmitted X-rays and are referred to as transmission X-ray images.

By comparison, a Z Backscatter image captures data from X-ray photons that are scattered from the object undergoing inspection. This primary scattering effect is known as "Compton Scattering." X-ray photons scatter differently when they encounter different types of materials. Compton scattering is material-dependent, with the lower atomic number materials scattering more strongly than the higher numbered ones. (Higher atomic number elements are more likely to absorb X-rays, either before or after being scattered.)



Sources
YouTube - Backscatter Van
http://www.youtube.com/watch?v=DGCd0KPJcMs&feature=player_embedded
$9.5M for Special Z-Backscatter Scan-Vans to Afghanistan & Iraq
http://www.defenseindustrydaily.com/95m-for-special-zbackscatter-scanvans-to-afghanistan-iraq-0967/
Z Backscatter: power, effectiveness and safety
http://www.as-e.com/products_solutions/z_backscatter.asp

Related
AS&E: Advanced X-ray Inspection Systems
http://www.as-e.com/index.asp
AS&E Introduces Z Backscatter Van X-ray Screening System, Ideal for Port and Border Security, and Force Protection. - Free Online Library
http://www.thefreelibrary.com/AS&E+Introduces+Z+Backscatter+Van+X-ray+Screening+System,+Ideal+for...-a0102467950
Full-Body Scan Technology Deployed In Street-Roving Vans - Andy Greenberg - The Firewall - Forbes
http://blogs.forbes.com/andygreenberg/2010/08/24/full-body-scan-technology-deployed-in-street-roving-vans/

Labels:

2010-08-25

Lose Weight by Drinking Water

Trying to lose weight? Drink more water


Researchers found that drinking two glasses of water before each meal may help dieters lose weight and keep it off.


Drinking Water Before Meals Helps Weight Loss

(CBS)  Drinking two glasses of water before each meal may help you lose weight, according to a new study presented Monday at the annual meeting of the American Chemical Society in Boston, Health.com reports.

Obese dieters who drank two 8-ounce glasses of water before breakfast, lunch and dinner lost five pounds more than dieters who didn't increase their water intake. Those who drank more water also kept more of the weight off after a year, said Brenda Davy, an associate professor at Virginia Tech in Blacksburg.


Clinical trial confirms effectiveness of simple appetite control method


“We are presenting results of the first randomized controlled intervention trial demonstrating that increased water consumption is an effective weight loss strategy,” said Brenda Davy, Ph.D., senior author on the study. “We found in earlier studies that middle aged and older people who drank two cups of water right before eating a meal ate between 75 and 90 fewer calories during that meal. In this recent study, we found that over the course of 12 weeks, dieters who drank water before meals, three times per day, lost about 5 pounds more than dieters who did not increase their water intake.”


Drinking more water before meals can help
promote weight loss.

“People should drink more water and less sugary, high-calorie drinks. It’s a simple way to facilitate weight management.”

Davy pointed out that folklore and everyday experience long have suggested that water can help promote weight loss. But there has been surprisingly little scientific information on the topic. Previous studies hinted that drinking water before meals reduces intake of calories. Lacking until now, however, has been the “gold-standard” evidence from a randomized, controlled clinical trial that compares weight loss among dieters who drink water before meals with those who do not.

The study included 48 adults aged 55-75 years, divided into two groups. One group drank 2 cups of water prior to their meals and the other did not. All of the subjects ate a low-calorie diet during the study. Over the course of 12 weeks, water drinkers lost about 15.5 pounds, while the non-water drinkers lost about 11 pounds.

Davy said water may be so effective simply because it fills up the stomach with a substance that has zero calories. People feel fuller as a result, and eat less calorie-containing food during the meal. Increased water consumption may also help people lose weight if they drink it in place of sweetened calorie-containing beverages, said Davy, who is with Virginia Tech in Blacksburg, Va.



Brenda Davy

Associate Professor

Research

Improving health behaviors: diet, physical activity, and weight management; Appetite control and food intake regulation; Beverage consumption and weight management; Dietary intake assessment.



Sources
Trying to lose weight? Drink more water - CNN.com
http://edition.cnn.com/2010/HEALTH/08/23/drink.water.lose.weight/?hpt=Sbin#fbid=75_9at2LgRX&wom=false
Drinking Water Before Meals Helps Weight Loss - CBS News
http://www.cbsnews.com/stories/2010/08/23/health/main6798331.shtml
Clinical trial confirms effectiveness of simple appetite control method
http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_ARTICLEMAIN&node_id=222&content_id=CNBP_025391&use_sec=true&sec_url_var=region1&__uuid=a733bd09-2fc8-403a-86ee-14ba49cf353d
Brenda Davy | Virginia Tech
http://www.hnfe.vt.edu/about_US/Bios_faculty/bio_davy_brenda.html

Related
Drink Water Before Meals, Lose Weight - CBS News Video
http://www.cbsnews.com/video/watch/?id=6800561n&tag=related;photovideo
Department of Human Nutrition, Foods and Exercise | Virginia Tech
http://www.hnfe.vt.edu/
Clinical trial confirms effectiveness of simple appetite control method | Virginia Tech News | Virginia Tech
http://www.vtnews.vt.edu/articles/2010/08/082310-cals-davy.html
Study Finds Water Helps Weight Loss | keyc.tv
http://www.keyc.com/node/41019
Six glasses of water a day makes you slim - mirror.co.uk
http://www.mirror.co.uk/news/top-stories/2010/08/24/six-glasses-of-water-a-day-makes-you-slim-115875-22509617/

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2010-08-23

Biofuel from Whisky Byproducts

Scottish Scientists Turn Whisky Into Biofuel 



[...] Researchers at Edinburgh Napier University have figured out how to turn the leftovers from one of Scotland’s biggest exports into biofuel. Made from byproducts of the whisky-making process, the scotch-derived biofuel is ready to run in ordinary automobile engines without requiring any modifications.


#

Super 'whisky' biofuel to power cars


Professor Martin Tangney


Professor Martin Tangney, Director of the Biofuel Research Centre at Edinburgh Napier University, is leading the ground-breaking research.

He said: “The EU has declared that biofuels should account for 10% of total fuel sales by 2020. We’re committed to finding new, innovative renewable energy sources.

“While some energy companies are growing crops specifically to generate biofuel, we are investigating excess materials such as whisky by-products to develop them.

"This is a more environmentally sustainable option and potentially offers new revenue on the back of one Scotland’s biggest industries. We’ve worked with some of the country’s leading whisky producers to develop the process.”

Collected from: News Details









What are biofuels?

Biofuels are any liquid, solid or gaseous fuels produced from organic matter. The extensive range of organic materials used for biofuel production includes starch and sugary plants such as corn, wheat or sugar cane; oily plants such as rape seed, soya beans or jatropha; vegetable oils and animal fats; wood and straw; algae and organic waste and others. Biofuels are commonly referred to as first generation, mainly bioethanol and biodiesel, or second generation, which cover a variety of technologies currently in the pipeline.

Collected from: What are biofuels?



Biobutanol - the superior biofuel

Butanol is a 4-carbon alcohol originally central to a number of industrial chemical processes. It is now recognised as an important transport fuel - with superior characteristics to ethanol.
 
Butanol is produced by solventogenic clostridia via the Acetone-Butanol-Ethanol fermentation. The history of the ABE fermentation stretches back to the early 1900s and it was once only second to ethanol as the largest industrial fermentation. Its demise was ultimately triggered by the availability of cheaper alternatives from the petrochemical industry. The search for a sustainable biofuel has now established biobutanol as a important transportation fuel.
Collected from: Butanol


Sources
Scottish Scientists Turn Whisky Into Biofuel | Popular Science
http://www.popsci.com/science/article/2010-08/scots-make-biofuel-byproducts-scotch-production
News Details
http://www.napier.ac.uk/media/Pages/NewsDetails.aspx?NewsID=151
YouTube - Whisky-fueled cars could add interesting twist when filling up at the petrol pump
http://www.youtube.com/watch?v=P7twbdxWfCo
YouTube - Scientists Raise A Glass To Whisky Biofuel
http://www.youtube.com/watch?v=wCjADYbJkiE
What are biofuels?
http://www.napier.ac.uk/randkt/rktcentres/bfrc/Pages/Whatarebiofuels.aspx
Butanol
http://www.napier.ac.uk/randkt/rktcentres/bfrc/Pages/Butanol.aspx

Related
Scots scientists create car biofuel from whisky by-products
http://www.physorg.com/news201327681.html
Scottish whisky to power cars | About WWF Scotland | WWF Scotland
http://scotland.wwf.org.uk/what_we_do/about_wwf_scotland/?4167/Scottish-whisky-to-power-cars
Scottish scientists develop whisky biofuel | Environment | guardian.co.uk
http://www.guardian.co.uk/environment/2010/aug/17/whisky-biobuel-scotland
BBC News - Whisky 'petrol' for cars developed by university
http://www.bbc.co.uk/news/uk-scotland-edinburgh-east-fife-10998281
Whisky Biofuel Available in a Few Years: 30% More Power than Ethanol : TreeHugger
http://www.treehugger.com/files/2010/08/whisky-biofuel.php
Scottish Researchers Turn Whiskey into Fuel | Inhabitat - Green Design Will Save the World
http://inhabitat.com/2010/08/18/scottish-researchers-transform-whiskey-into-fuel/
Biofuel Research Centre
http://www.napier.ac.uk/randkt/rktcentres/bfrc/Pages/default.aspx

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2010-08-20

The Breaking Spaghetti Mystery

The spaghetti mystery that baffled a Manhattan Project scientist



Why do strands of spaghetti so rarely snap into only two pieces? Take a look at the solution to a mystery that, no fooling, baffled famed physicist Richard Feynman.



Feynman's Interest in Spaghetti

In a 1993 Nova program (by film-maker Sykes) and the 1994 book "No Ordinary Genuis" (edited by Sykes) Daniel W. Hillis fondly recalls an evening with Feynman breaking spaghetti, unsuccessfully trying to discover why it breaks in three pieces.
Here is a video snippet of the interview:
Spaghetti Stumps The Chief. 150KB, 60 secs

The seemingly simple problem was succinctly posed by Hillis as "Why does spaghetti break in 3 pieces?" ...

Collected from: Feynman Videos

How bent spaghetti break


Bent dry spaghetti do not break in half but instead in three or more pieces. With the aim to explain this surprising phenomenon, we studied a related problem, namely the dynamics of an elastic rod that is bent quasi-statically and then suddenly set free. Counter-intuitively, we find that the mere release of the rod induces a stress increase. The multiple breaking of bent rods, like dry spaghetti pasta, can then be understood as a cascade of releases (loss of cohesion upon breakings) followed by stress increases leading to new cracks.

Collected from: Breaking spaghetti







Breaking spaghetti - short story

B. Audoly, S. Neukirch

[...]


Experiment. To study the dynamics of the rod following the first breaking event, we introduce a catapult experiment: a rod is bent quasi-statically and then suddenly released at one end. [...]

Elastic model. We used the Kirchhoff equations for elastic rods to study the dynamics of the rod in this catapult geometry. When released, the rod follows three regimes successively: (1) the released end quickly straightens up at short times, giving birth to a burst of flexural waves that (2) travel along the rod to the clamped end and (3) are amplified by reflexions on the opposite (clamped) edge.


[...]

 Conclusion We have shown that releasing an elastic brittle rod from a bent configuration is sufficient to make it break. This counter-intuitive result explains why brittle rods break in several pieces when bent beyond their limit curvature: a first breaking occurs when the curvature exceeds its limit value in some place, after which, as described above, flexural waves travel along the two newly formed halves of the rod, where they locally increase the curvature further. This increase leads to new breakings that give rise to new travelling waves, and a cascade mechanism can take place.


Sources
The mystery of spaghetti that baffled a Manhattan Project scientist
http://io9.com/5613155/when-spaghetti-snaps
Feynman Videos
http://heelspurs.com/feynman.html
Breaking spaghetti
http://www.lmm.jussieu.fr/spaghetti/
YouTube - Breaking Spaghetti
http://www.youtube.com/watch?v=I7qPrSeIHKM
YouTube - Breaking dry spaghetti
http://www.youtube.com/watch?v=8GutricnMNc
Breaking spaghetti - short story
http://www.lmm.jussieu.fr/spaghetti/short_story.html

Related
Movies - Breaking spaghetti
http://www.lmm.jussieu.fr/spaghetti/movies-6-more.html
Why spaghetti does not break in half | ZDNet
http://www.zdnet.com/blog/emergingtech/why-spaghetti-does-not-break-in-half/17
Buckling Spaghetti - Faster Than Euler
http://www.math.psu.edu/belmonte/spaghetti.html


Labels: ,

2010-08-17

ELI - Extreme Light Infrastructure - Ultra High Power Lasers

Physics Buzz: Lasers reaching their limit


Somebody is going to have to break the news to Darth Vader. His Death Star's planet destroying potential is going to be way behind schedule. Research scheduled to be published in an upcoming issue of the journal Physical Review Letters shows that lasers are already close to reaching their maximum intensity and that the next generation of lasers currently being developed might be able to reach that limit.

Coming Generation of Lasers May Be the Most Powerful Lasers That Will Ever Lase

The theoretical energy ceiling for lasers is approaching


Construction Worker in Laser Target Chamber at National Ignition Facility Lawrence Livermore National Laboratory

The most powerful lasers now being built, such as the forthcoming Extreme Light Infrastructure (ELI) project underway in Europe, may approach the physical ceiling of laser intensity -- they may turn out to be the most powerful lasers that ever can be built, says a new article on the PhysicsBuzz blog.

That finite limit on how intense a laser can get is hypothesized to exist because, at sufficiently high energies, matter can be created out of light.


Extreme Light Infrastructure in a few words

A european facility opening new avenues to reveal the secrets of matter on ultra-short timescales

The first infrastructure worldwide dedicated to :

  • Investigation of laser-matter interactions in the unexplored ultra-relativistic regime.
  • Development of unprecedented intense ultra-short particle and radiation sources for fundamental and applied sciences.
“Physicists are planning lasers powerful enough to rip apart the fabric of space and time”
Nature, 446 (2007)


Exotic Physics and Theory


Ultra-high fields of high-power, short-pulse lasers pose very important possibilities for fundamental physics. The main goal of this Research Activity is to explore both theoretically and experimentally the ultra-relativistic (above 1023 W/cm2) regime of laser-matter interaction, called Exotic physics.

[...] In essence, ultra-relativistic intensities could unify nuclear physics, high-energy physics, astrophysics and cosmology.

Apart from these truly exotic research fields, other nonlinear quantum electrodynamics effects could be accessed at slightly modest fields. The ELI community is eager to study such phenomena which consist in converting photon energy directly into creation of electrons and positrons. [...]



Some of the particular QED phenomena that will be studied at ELI are:

  1. Electron-positron plasmas
  2. Vacuum four-wave mixing
  3. Vacuum polarisation
  4. Vacuum birefringence
  5. Unruh radiation
  6. QED cascades: Inverse Compton Scattering
  7. Quark-gluon plasmas





Sources
Physics Buzz: Lasers reaching their limit
http://physicsbuzz.physicscentral.com/2010/08/lasers-reaching-their-limit.html
Coming Generation of Lasers May Be the Most Powerful Lasers That Will Ever Lase | Popular Science
http://www.popsci.com/technology/article/2010-08/next-generation-lasers-may-be-most-powerful-lasers-will-ever-lase
ELI : European Project > Extreme Light Infrastructure
http://www.extreme-light-infrastructure.eu/
Exotic Physics and Theory
http://www.eli-beams.eu/en/vedecke-aktivity-eli/sekundarni-zdroje-pro-mezioborove-aplikace/exoticka-fyzika-a-teorie-vyzkumna-aktivita-6/

Related
LASERLAB Europe Transnational Access Programme
http://www.eli-beams.eu/laserlab-europe-transnational-access-programme/
ELI project > Extreme Light Infrastructure
http://www.extreme-light-infrastructure.eu/what-is-eli.php?PHPSESSID=51933186a5217e2e1a6205ef8ee661ae
ELISAC report
http://docs.google.com/viewer?url=http://www.extreme-light-infrastructure.eu/docs/Brochure-and-Communication/ELI-SAC-report-id357.pdf
LASERLAB EUROPE — LASERLAB-EUROPE
http://www.laserlab-europe.net/
The Astronomist: Limits on Lasers
http://theastronomist.fieldofscience.com/2010/08/limits-on-lasers.html


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2010-08-15

Invisibility Cloak of Silk and Gold

Scientists Finally Make 'Invisibility Cloak' With Silk

A scientist at Tufts University alongwith some colleagues from the Boston University has finally created an "Invisibilty Cloak" and that too from silk and coated in gold.

This new material only works on long terahertz waves but some scientists who took part in the development of the metamaterial think that the cloak will also work in much smaller wavelengths.


Discovery News 

Invisibility Cloak Made From Silk

Is a silk invisibility cloak in our future? For now a silk invisibility cloak works only on relatively long terahertz waves.

Invisibility cloaks, along with their optically exotic cousins, perfect absorbers and perfect reflectors and others, belong to a special class of materials known as metamaterials. Unlike most materials, which derive optical properties like color from their chemical make up, metamaterials derive their properties from the physical structure.

A curly cue, or short spiral, is a common  metamaterial structure. Scientists call them split ring resonators, or SSRs. Usually scrawled into metals, SSR can give ordinary materials extraordinary abilities, like absorbing or reflecting all the specific wavelengths of light, or bending a wavelength around an object.

To create their silk-based metamaterial, the Tufts and Boston University scientists, including Richard Averitt, started with a one-centimeter-square piece of silkworm silk. (In another recent paper, Omenetto's colleague and another co-author of the Advanced Material's paper, David Kaplan of Tufts, created silk-producing bacteria.) Onto that tiny piece of dielectric silk they stenciled 10,000 gold resonators.

The potential applications of silk-based invisibility are huge. Omenetto and his colleagues at Tufts aren't even focused on Harry Potter or Star Trek-style invisibility materials, although he says that is one potential application.

Their main focus is in biomedical applications. [...]


Silk-based invisibility would also allow doctors and radiologists to cloak various organs or tissues and see through them, said Omenetto, getting a better image of the organs or tissues usually hidden behind.


 

Implantable silk metamaterials could advance biomedicine, biosensing

In Situ Bio-Sensing

To demonstrate the concept, the researchers conducted a series of in vitro experiments that examined the electromagnetic response of the silk metamaterials when implanted under thin slices of muscle tissue. They found that the metamaterials retained their novel resonance properties while implanted. The same process could be readily adapted to fabricate silk metamaterials at other frequencies, according to Tao.

"Our approach offers great promise for applications such as in situ bio-sensing with implanted medical devices and the transmission of medical information from within the human body," says Omenetto. "Imagine the benefits of monitoring the rate of drug delivery from a drug-eluting cardiac stent, making a perfect absorber that can be implanted to attack diseased tissue by heat, or wrapping an 'invisibility cloak' around an organ to examine the tissue behind it."



Tufts University

Implantable Silk Metamaterials Could Advance Biomedicine, Biosensing


Below, silk-based metamaterial photographed on a background of silk fibers. The tiny, flexible devices can be rolled into capsule-like shapes (above). (Credit: Hu Tao, Tufts University)




Sources
Scientists Finally Make 'Invisibility Cloak' With Silk
http://www.allvoices.com/contributed-news/6516985-scientists-finally-make-invisibility-cloak-with-silk
Invisibility Cloak Made From Silk : Discovery News
http://news.discovery.com/tech/silk-invisibility-cloak.html
Implantable silk metamaterials could advance biomedicine, biosensing
http://www.sciencedaily.com/releases/2010/08/100812135938.htm
Implantable Silk Metamaterials Could - Tufts University
http://news.tufts.edu/releases/release.php?id=198

Related
home
http://ase.tufts.edu/biomedical/unolab/home.html
silk optics
http://ase.tufts.edu/biomedical/unolab/silk_optics.html
Behind the Secrets of - Tufts University
http://news.tufts.edu/releases/release.php?id=191
Implantable Silk Metamaterials Could Advance Biomedicine, Biosensing | Before It's News
http://beforeitsnews.com/story/136/463/Implantable_Silk_Metamaterials_Could_Advance_Biomedicine,_Biosensing.html
Richard Averitt (Boston University, Physics Department)
http://physics.bu.edu/people/show/raveritt


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