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 Sequencing the DNA of Things with the Materials Genomics Initiative
30.03.2015 | West Virginia University - Eberly College of Arts and Sciences

nachricht Electrifying Research: Piezoelectric Effects for the Suppression of Material Stresses
30.03.2015 | Austrian Science Fund FWF

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Rostocker Forscher entwickeln Mess-System für Schiffbau-Versuchsanstalten

Durch wissenschaftlich fundierte Daten der Forscher um Professor Nils Damaschke vom Institut für Allgemeine Elektrotechnik der Universität Rostock wird es künftig möglich, die Propellerform für Schiffe so zu optimieren, dass weniger Kraftstoff verbraucht und der Propellerverschleiß auf Grund von Kavitation reduziert werden kann. Die Wissenschaftler arbeiten inzwischen an der weiteren Verfeinerung eines kommerziellen Mess-Systems für die weltweit agierenden Schiffbau-Versuchsanstalten.

Kleinste Partikel spielen im täglichen Leben eine immer größere Rolle. Ob es sich um Schadstoffe in der Luft (Feinstaubbelastung) oder Zerstäubungsprozesse...

Im Focus: Den Synapsen bei der Arbeit zusehen

Göttinger Forscher beobachten Synapsenaktivität im Gehirn lebender Fruchtfliegen

Wissenschaftler der Universität Göttingen haben mit einer neuen Methode die Aktivität von Nervenzellen im Gehirn lebender Fruchtfliegen beobachtet. Bislang...

Im Focus: FiberLab-Roboter begeistert auf Photonics West in San Francisco

Mit ihrem „humanisierten“ Roboter zeigten Anna Lena Baumann und Wolfgang Schade erstmalig die erfolgreiche Umsetzung der 3D-Navigation über eine neuartige Lasermethode, der Standard Single-Mode-Glasfaser. Mehr als 17.000 Teilnehmer konnten den Roboter und FiberLab, das erste Projekt des Photonik Inkubators in Göttingen, auf der Photonics West in San Francisco kennen lernen.

Mit Hilfe eines in die Kleidung eingenähten Fasersensors wurden Armbewegungen eines Probanden dokumentiert und nach entsprechender Auswertung an den Roboter...

Im Focus: Femto Photonic Production: Neue Verfahren mit Ultrakurzpulslasern für die Fertigung von morgen

Für die deutsche Wirtschaft spielt die Lasertechnik eine herausragende Rolle: Etwa 40 Prozent der weltweit verkauften Strahlquellen und 20 Prozent der Lasersysteme für die Materialbearbeitung stammen aus Deutschland.

Beim Einsatz von Lasern in der Produktion sind deutsche Unternehmen führend. Diese Stärken gilt es zu erhalten und auszubauen. Deswegen hat das...

Im Focus: Theorie der starken Wechselwirkung bestätigt: Supercomputer bestimmt Neutron-Proton-Massendifferenz

Nur weil das Neutron ein klein wenig schwerer ist als das Proton, haben Atomkerne genau die Eigenschaften, die unsere Welt und letztlich unsere Existenz ermöglichen.

80 Jahre nach der Entdeckung des Neutrons ist es einem Team aus Frankreich, Deutschland und Ungarn unter Führung des Wuppertaler Forschers Zoltán Fodor nun...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

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

Premiere für die "innteract conference"

30.03.2015 | Veranstaltungen

Startup Weekend: In 54 Stunden von der Gründungsidee zur Firmengründung

30.03.2015 | Veranstaltungen

Große Bühne für Wissenschaft in drei Minuten

30.03.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

BLS Cargo bestellt 15 Mehrsystem-Loks

30.03.2015 | Unternehmensmeldung

Elastografie verbessert Therapie bei Morbus Crohn

30.03.2015 | Medizintechnik

Premiere für die "innteract conference"

30.03.2015 | Veranstaltungsnachrichten