- Earth Sciences - 12:01 Chimps use clay to detox and as a mineral supplement
- Business - 11:01 Should Labour really be agonising over the Left Right divide?
- Medicine - 08:01 Novartis partners with Phase 4 Partners and institutional investors to help create Mereo BioPharma Group Ltd
- Business - 06:02 Secretary of State for Business announces investment boost for UK’s largest dynamic test facility
- Microtechnics - Jul 29 Making the new silicon
- Physics - Jul 29 Rogue wave theory to save ships »
- Social Sciences - Jul 28 Bruce Kidd: sprinter Dutee Chand’s historic win for right to compete "affirms women exactly as they are"
- Medicine - Jul 28 How stem cell research and regenerative medicine saved this man's life
- Pedagogy - Jul 28 'Redshirting' kids yields no advantage in higher education
- Physics - Jul 28 Physicists close in on world's most sensitive resonators
- Agronomy - Jul 28 More secondary schools serve healthier lunches
- Medicine - Jul 28 McGill gets $91.5 Mln in CIHR funding
- Life Sciences - Jul 28 Young Animal Welfare Scientist of the Year
- Mechanical Engineering - Jul 28 EPSRC rail consortium shows how to cut costs and reduce delays
- Medicine - Jul 28 UCLA stem cell researchers receive $7.4 million to study immunodeficiency disorder
Squid and zebrafish cells inspire camouflaging smart materials
Researchers from the University of Bristol have created artificial muscles that can be transformed at the flick of a switch to mimic the remarkable camouflaging abilities of organisms such as squid and zebrafish.They demonstrate two individual transforming mechanisms that they believe could be used in ’smart clothing’ to trigger camouflaging tricks similar to those seen in nature.
The study is published today [2 May] in IOP Publishing’s journal Bioinspiration and Biomimetics , and is accompanied by a video ( www.youtube.com/watch’v=W2CgtJU3ckY ) showing the camouflaging in action.
"We have taken inspiration from nature’s designs and exploited the same methods to turn our artificial muscles into striking visual effects," said lead author of the study Jonathan Rossiter , Senior Lecturer in the Department of Engineering Mathematics.
The soft, stretchy, artificial muscles are based on specialist cells called chromatophores that are found in amphibians, fish, reptiles and cephalopods, and contain pigments of colours that are responsible for the animals’ remarkable colour-changing effects.
The colour changes in these organisms can be triggered by changes in mood, temperature, stress or something visible in the environment, and can be used for camouflage, communication or attracting a mate.
Two types of artificial chromatophores were created in the study: the first based on a mechanism adopted by a squid and the second based on a rather different mechanism adopted by zebrafish.
A typical colour-changing cell in a squid has a central sac containing granules of pigment. The sac is surrounded by a series of muscles and when the cell is ready to change colour, the brain sends a signal to the muscles and they contract. The contracting muscles make the central sacs expand, generating the optical effect which makes the squid look like it is changing colour.
The fast expansion of these muscles was mimicked using dielectric elastomers (DEs) - smart materials, usually made of a polymer, which are connected to an electric circuit and expand when a voltage is applied. They return to their original shape when they are short circuited.
In contrast, the cells in the zebrafish contain a small reservoir of black pigmented fluid that, when activated, travels to the skin surface and spreads out, much like the spilling of black ink. The natural dark spots on the surface of the zebrafish therefore appear to get bigger and the desired optical effect is achieved. The changes are usually driven by hormones.
The zebrafish cells were mimicked using two glass microscope slides sandwiching a silicone layer. Two pumps, made from flexible DEs, were positioned on both sides of the slide and were connected to the central system with silicone tubes; one pumping opaque white spirit, the other a mixture of black ink and water.
"Our artificial chromatophores are both scalable and adaptable and can be made into an artificial compliant skin which can stretch and deform, yet still operate effectively. This means they can be used in many environments where conventional ’hard’ technologies would be dangerous, for example at the physical interface with humans, such as smart clothing," continued Rossiter.
Paper: Biomimetic chromatophores for camouflage and soft active surfaces, Jonathan Rossiter, Bryan Yap and Andrew Conn, Bioinspiration & Biomimetics, published online 2 May 2012.
Last job offers
- Physics/Materials Science - 28.7
Faculty Position in Plasma Physics
- Civil Engineering - 28.7
Faculty Positions in Transportation Engineering and Transportation Systems
- Computer Science/Telecom - 24.7
4 Doctoral Student/Post-Doc Positions (Salary Scale 13 TV-L)
- Life Sciences - 22.7
Wissenschaftliche Assistenten und Assistentinnen in angewandter Forschung
- Pedagogy/Education Science - 21.7
Professeur-e ordinaire ou associé-e dans le domaine Intervention en situation scolaire
- Pedagogy/Education Science - 20.7
Projektleiter/in als Wissensch. Mitarbeiter/in (80−100 %) Arbeits- und Organisationspsychologie...
- Environmental Sciences - 28.7
Lecturer / Senior Lecturer / Associate Professor in Environmental Management
- Environmental Sciences - 27.7
Assistant Professor: Global Environmental Change (1, 0 FTE)
- Arts and Design - 15.7
Universitätsprofessorin / Universitätsprofessor für das Fach Musiktheater-Regie (BV gem. § 99 UG )
- Social Sciences - 13.7
Universitätsprofessorin / Universitätsprofessor für das Fach Instrumental- und Gesangspädagogik (BV gem....
- - 28.7
- - 28.7
- Microtechnics - 28.7
Associate Professor in Oceanic Engineering Science
- Mechanical Engineering - 28.7
Assistant Professor in Additive Manufacturing Operations Research
- Medicine/Pharmacology - 29.7
Family Medicine - MEDEX - Assistant or Associate or Full Professor WOT (AA12561)
- Pedagogy/Education Science - 29.7
AGRI Research Chair in Gambling Policy