The material that's like an octopus

Jan 24, 2013 by Pete Wilton

(Phys.org)—The atomic structure of a zinc-based material has a surprising amount in common with the tentacles of an octopus, Oxford University researchers have found.

When pressure is applied all around them most materials shrink. But materials exhibiting a rare property known as negative linear (NLC) are different.

'When pressure is applied all around NLC materials, instead of their dimensions getting shorter, they reduce their volume by getting longer,' Andrew Goodwin of Oxford University's Department of Chemistry tells me, 'think of it a bit like one of those collapsible wine racks.'

Andrew and his Oxford colleagues led an international team studying the unusual thermal properties of the material zinc dicyanoaurate. What they did not expect to find was that its -like structure gave it uniquely powerful NLC behaviour, far beyond the kind of contraction and expansion exhibited by ordinary engineering materials.

A report of their research is published in .

There's widespread interest in NLC because of how materials with these properties could be used in or new types of sensors.

'It was quite surprising to discover that zinc dicyanoaurate is made up of structures that act rather like sets of supramolecular springs that cause it to behave in this way,' says Andrew. 'What's particularly exciting is that these properties scale up from the atomic scale to that of manmade objects and structures, suggesting all sorts of possible applications.'

Often scientists take inspiration from , or even try to copy them, but in this case the discovery of atomic structures could make them look afresh at biology.

'It seems that the has found a way of harnessing the same intrinsic properties we've found in zinc dicyanoaurate,' Andrew explains. 'When it wants to contract a particular limb an octopus squirts liquid into the centre of a helical chamber inside the tentacle. This creates the equivalent of negative pressure on the tentacle, causing it to get fatter in cross section and, through the muscle architecture, contract in length.

'These same geometrical motifs found in materials at the can also be found around us in the Animal Kingdom.'

The first to benefit from zinc dicyanoaurate's NLC properties could be the construction industry: including an ingredient like it in cement, that 'pushes back' when other components swell due to the presence of water, could help to prevent cracking in structures.

Other likely applications include the optical world where it could be used to create adjustable lenses or sensors that respond to pressure in a different way from those made of conventional materials.

Could it one day be used to make the sort of artificial tentacles sported by Spider-Man's nemesis Doc Ock? That's one application that may have to wait.

A report of the research, entitled 'Giant negative linear compressibility in zinc dicyanoaurate', is published in this week's Nature Materials.

Explore further: Aromatic couple makes new chemical bonds

More information: www.nature.com/nmat/journal/vaop/ncurrent/full/nmat3551.html

Related Stories

Magnetic spin on non-magnetic materials

Feb 14, 2012

(PhysOrg.com) -- Nanotechnologists from the University of Twente's MESA+ and MIRA research institutes have developed a method for incorporating magnetic elements into non-magnetic materials in a highly controlled ...

Shells, silicon & neighbourly atoms

Mar 24, 2010

What do shells, solar panels and DVDs have in common? At the atomic scale they are 'amorphous', that is -- unlike crystals -- they are built from irregular arrangements of atoms.

Silkworm structures drive push for new materials

May 03, 2012

(Phys.org) -- Research published in the peer-review Journal of the Royal Society Interface on Wednesday presents a close look at the structure and physical properties of silkworm cocoons. The paper’s resear ...

Recommended for you

Chemists characterize 3-D macroporous hydrogels

1 hour ago

Carnegie Mellon University chemists have developed two novel methods to characterize 3-dimensional macroporous hydrogels—materials that hold great promise for developing "smart" responsive materials that ...

Substrates change nanoparticle reactivity

6 hours ago

(Phys.org)—Nanoscale materials tend to behave differently than their bulk counterparts. While there are many theories as to why this happens, technological advances in scanning tunneling microscopy (STM) ...

Reviving cottonseed meals adhesives potential

9 hours ago

Cottonseed meal—the leftovers after lint and oil are extracted from cottonseed—is typically fed to ruminant livestock, such as cows, or used as fertilizer. But Agricultural Research Service scientists ...

New concrete composite can heal itself

9 hours ago

In the human body, small wounds are easily treated by the body itself, requiring no further care. For bigger wounds to be healed, the body may need outside assistance. Concrete is like a living body, in that ...

Actuators that mimic ice plants

10 hours ago

Engineers developing moveable robot components may soon take advantage of a trick plants use. Researchers at the Max Planck Institute of Colloids and Interfaces in Potsdam and Harvard University in Cambridge ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.