(NanoRealm) - Banknotes could become as beautiful as butterfly wings one day using technology borrowed from nature.

British scientists have found a way to mimic the iridescent colours of tropical butterflies, created by light bouncing off microscopic wing structures.

The research could be used to make banknotes and credit cards that are visually striking and harder to forge.

“These artificial structures could be used to encrypt information in optical signatures on banknotes to protect them against forgery,” said Mathias Kolle, a PhD student at the University of Cambridge.

“In future we could see structures based on butterflies’ wings shining from a £10 note or even our passports.”

The Cambridge team studied the Indonesian peacock, or swallowtail, butterfly — Papilio blumei — whose vivid green-and-blue wings have an intricate surface pattern.

They made identical copies of the structures using nanotechnology.

Recreating the colours of beetles, butterflies and moths has previously proved elusive because of the technical challenge of precisely shaping materials on such a small scale.


“We have unlocked one of nature’s secrets and combined this knowledge with state-of-the-art nanofabrication to mimic the intricate optical designs found in nature,” Mr Kolle said.

“Although nature is better at self-assembly than we are, we have the advantage that we can use a wider variety of artificial, custom-made materials to optimise our optical structures.”

The research is published in the journal Nature Nanotechnology.

The Indonesian peacock may use the security potential of its wing structure to encrypt itself, the scientists believe.

“The shiny green patches on this tropical butterfly’s wing scales are a stunning example of nature’s ingenuity in optical design,” Mr Kolle said.

“Seen with the right optical equipment these patches appear bright blue but with the naked eye they appear green.

“This could explain why the butterfly has evolved this way of producing colour. If its eyes see fellow butterflies as bright blue, while predators only see green patches in a green tropical environment, then it can hide from predators at the same time as remaining visible to members of its own species.”

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TimesOnline UK: (http://www.timesonline.co.uk/tol/news/uk/article7140807.ece)

(NanoRealm) - A team at Cornell University has developed a technique to permanently coat cotton fibers with electrically conductive nanoparticles. The result makes cotton electronically conductive, while continuing to be lightweight, flexible, and comfortable.

The innovation came from the work of Juan Hinestroza and his colleagues at universities in Bologna and Cagliari, Italy. Dr. Hinestroza, currently an assistant professor of Fiber Science and Apparel Design, earned degrees in chemical and biomolecular engineering from his native country, Columbia, and Tulane University. His research specializes in creating multifunctional fibers by manipulation of nanoscale phenomena.

Focus: Modify, Create and Develop

His work has three focus points: modification of existing textile materials, creation of fibers from polymers, and "development of mathematical models and metrology tools based on scanning probe microscopy to assess nanoscale phenomena on low energy surfaces and high radius of curvature". Nanofibers could be used in, antibacterial, anti-odor, active camouflage and anti-counterfeiting applications. Dr. Hinestroza has worked with magnetic nanoparticles that can create invisible signatures that mints can inscribe on dollar bills.

As to his efforts with textiles, Dr. Hinestroza said. "Previous technologies have achieved conductivity but the resulting fiber becomes rigid and heavy. Our new techniques make our yarns friendly to further processing such as weaving, sewing and knitting."
The science underlying the new cloth is more familiar to readers in the form of conductive inks or pastes of metals such as silver or copper which can be coated onto glass to form an electrically conductive surface. These metal coated glass substrates are used in chips for electronic components. This science is the subject of many patents, included a patent application related to "conductive nanoparticle substrate and method of manufacture" purporting to have "specific qualities that permit the reflow of solder across the surface for the attachment of electrical components, namely high electrical conductivity, good adhesion, scratch resistance."

Combination of Technology and Fashion Became Reality

Combining the technology with cloth will change the future of fabric. Cotton is the vehicle presently. A theme extolling this fiber, The Fabric Of Our Lives, appeared in 1989. Cotton Incorporated, the research and marketing company representing upland cotton even sings its praises in commercials in a song first performed by Richie Havens and later by Aaron Neville.

Cotton Incorporated began a recycling program in 2006 called Cotton - From Blue to Green. They have recycled enough denim to create natural cotton fiber insulation for over 540 homes. Gap stores are participating in a two week drive giving customers who donate denim a 30 percent discount on new denim purchases through March 14. The donated denims will be converted into UltraTouch Natural Cotton Fiber Insulationand donated to needy communities.

Gap brands include Banana Republic and Old Navy. Other retailers who participate in the Cotton - From Blue to Green program include Guess, Vanity and Warner Bros.

Getting back onto the subject of Cornell's University nano-cotton, It will be interesting to tune in to Cornell’s annual Design League Fashion Show, was held on March 13, 2010.

The theme of this year's show is Once Upon A Runway, and show attendants will see the unveiling of a solar-powered dress designed by Hinestroza's student, Abbey Liebman.

Powering your smartphone or MP3 player while on the move couldn’t be easier. The new design uses flexible solar cells which power small electronics from a USB charger in the waist of the dress. The event gives Liebman and other students involved in design, graphics, photography, and theater production an opportunity to showcase their creativity.

Could wearning nano-cotton be the new fashion of the future? We'll leave that for your consideration.

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Source: Bright Side Of News (http://www.brightsideofnews.com/news/2010/3/11/fashion-the-land-of-cotton-is-going-nanotech.aspx)