Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Bioinspired fibers change color when stretched

29.01.2013
Color-tunable photonic fibers mimic the fruit of the “bastard hogberry” plant
A team of materials scientists at Harvard University and the University of Exeter, UK, have invented a new fiber that changes color when stretched. Inspired by nature, the researchers identified and replicated the unique structural elements that create the bright iridescent blue color of a tropical plant’s fruit.

The multilayered fiber, described today in the journal Advanced Materials, could lend itself to the creation of smart fabrics that visibly react to heat or pressure.

“Our new fiber is based on a structure we found in nature, and through clever engineering we’ve taken its capabilities a step further,” says lead author Mathias Kolle, a postdoctoral fellow at the Harvard School of Engineering and Applied Sciences (SEAS). “The plant, of course, cannot change color. By combining its structure with an elastic material, however, we’ve created an artificial version that passes through a full rainbow of colors as it’s stretched.”
Since the evolution of the first eye on Earth more than 500 million years ago, the success of many organisms has relied upon the way they interact with light and color, making them useful models for the creation of new materials. For seeds and fruit in particular, bright color is thought to have evolved to attract the agents of seed dispersal, especially birds.

The fruit of the South American tropical plant, Margaritaria nobilis, commonly called “bastard hogberry,” is an intriguing example of this adaptation. The ultra-bright blue fruit, which is low in nutritious content, mimics a more fleshy and nutritious competitor. Deceived birds eat the fruit and ultimately release its seeds over a wide geographic area.

“The fruit of this bastard hogberry plant was scientifically delightful to pick,” says principal investigator Peter Vukusic, Associate Professor in Natural Photonics at the University of Exeter. “The light-manipulating architecture its surface layer presents, which has evolved to serve a specific biological function, has inspired an extremely useful and interesting technological design.”

Vukusic and his collaborators at Harvard studied the structural origin of the seed’s vibrant color. They discovered that the upper cells in the seed’s skin contain a curved, repeating pattern, which creates color through the interference of light waves. (A similar mechanism is responsible for the bright colors of soap bubbles.) The team’s analysis revealed that multiple layers of cells in the seed coat are each made up of a cylindrically layered architecture with high regularity on the nano- scale.

The team replicated the key structural elements of the fruit to create flexible, stretchable and color-changing photonic fibers using an innovative roll-up mechanism perfected in the Harvard laboratories.

“For our artificial structure, we cut down the complexity of the fruit to just its key elements,” explains Kolle. “We use very thin fibers and wrap a polymer bilayer around them. That gives us the refractive index contrast, the right number of layers, and the curved, cylindrical cross-section that we need to produce these vivid colors.”

The researchers say that the process could be scaled up and developed to suit industrial production.
“Our fiber-rolling technique allows the use of a wide range of materials, especially elastic ones, with the color-tuning range exceeding by an order of magnitude anything that has been reported for thermally drawn fibers,” says coauthor Joanna Aizenberg, Amy Smith Berylson Professor of Materials Science at Harvard SEAS, and Kolle’s adviser. Aizenberg is also Director of the Kavli Institute for Bionano Science and Technology at Harvard and a Core Faculty Member at the Wyss Institute for Biologically Inspired Engineering at Harvard.

The fibers’ superior mechanical properties, combined with their demonstrated color brilliance and tunability, make them very versatile. For instance, the fibers can be wound to coat complex shapes. Because the fibers change color under strain, the technology could lend itself to smart sports textiles that change color in areas of muscle tension, or that sense when an object is placed under strain as a result of heat.

Additional coauthors included Alfred Lethbridge at the University of Exeter, Moritz Kreysing at Ludwig Maximilians University (Germany), and Jeremy B. Baumberg, Professor of Nanophotonics at the University of Cambridge (UK).

This research was supported by the U.S. Air Force Office of Scientific Research Multidisciplinary University Research Initiative, by the UK Engineering and Physical Sciences Research Council, and through a postdoctoral research fellowship from the Alexander von Humboldt Foundation. The researchers also benefited from facilities at the Harvard Center for Nanoscale Systems, which is part of the National Nanotechnology Infrastructure Network supported by the U.S. National Science Foundation. The Wyss Institute for Biologically Inspired Engineering at Harvard also contributed to this research.

Caroline Perry | EurekAlert!
Further information:
http://www.seas.harvard.edu
http://www.seas.harvard.edu/news-events/press-releases/bioinspired-fibers-change-color-when-stretched

More articles from Materials Sciences:

nachricht Clay nanotube-biopolymer composite scaffolds for tissue engineering
02.05.2016 | Kazan Federal University

nachricht Personal cooling units on the horizon
29.04.2016 | Penn State

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Erste Filmaufnahmen von Kernporen

Mithilfe eines extrem schnellen und präzisen Rasterkraftmikroskops haben Forscher der Universität Basel erstmals «lebendige» Kernporenkomplexe bei der Arbeit gefilmt. Kernporen sind molekulare Maschinen, die den Verkehr in und aus dem Zellkern kontrollieren. In ihrem kürzlich in «Nature Nanotechnology» publizierten Artikel erklären die Forscher, wie bewegliche «Tentakeln» in der Pore die Passage von unerwünschten Molekülen verhindern.

Das Rasterkraftmikroskop (AFM) ist kein Mikroskop zum Durchschauen. Es tastet wie ein Blinder mit seinen Fingern die Oberflächen mit einer extrem feinen Spitze...

Im Focus: Nuclear Pores Captured on Film

Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore.

Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly...

Im Focus: 2+1 ist nicht immer 3 - In der Mikro-Welt macht Einigkeit nicht immer stark

Wenn jemand ein liegengebliebenes Auto alleine schiebt, gibt es einen bestimmten Effekt. Wenn eine zweite Person hilft, ist das Ergebnis die Summe der Kräfte der beiden. Wenn zwei kleine Teilchen allerdings ein weiteres kleines Teilchen anschieben, ist der daraus resultierende Effekt nicht notwendigerweise die Summe ihrer Kräfte. Eine kürzlich in Nature Communications veröffentlichte Studie hat diesen merkwürdigen Effekt beschrieben, den Wissenschaftler als „Vielteilchen-Effekt“ bezeichnen.

 

Im Focus: 2+1 is Not Always 3 - In the microworld unity is not always strength

If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”

In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...

Im Focus: Winzige Mikroroboter, die Wasser reinigen können

Forscher des Max-Planck-Institutes Stuttgart haben winzige „Mikroroboter“ mit Eigenantrieb entwickelt, die Blei aus kontaminiertem Wasser entfernen oder organische Verschmutzungen abbauen können.

In Zusammenarbeit mit Kollegen in Barcelona und Singapur verwendete die Gruppe von Samuel Sánchez Graphenoxid zur Herstellung ihrer Motoren im Mikromaßstab. D

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

UFW-Fachtagung im Vorzeichen von Big Data und Industrie 4.0

03.05.2016 | Veranstaltungen

analytica conference 2016 in München - Foodomics, mehr als nur ein Modebegriff?

03.05.2016 | Veranstaltungen

Diabetes Kongress 2016: Diabetes schädigt das Herzkreislauf-System

02.05.2016 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Hepatitis C-Virus missbraucht den Fettstoffwechsel der Leber

03.05.2016 | Biowissenschaften Chemie

UFW-Fachtagung im Vorzeichen von Big Data und Industrie 4.0

03.05.2016 | Veranstaltungsnachrichten

Ein starkes Team: B2RUN und moove bringen Firmen in Bewegung

03.05.2016 | Unternehmensmeldung