Researchers design metamaterial that buckles selectively

June 10, 2015, Leiden University
Researchers design metamaterial that buckles selectively

Researchers from Leiden University, the Netherlands, have designed a novel metamaterial that buckles on demand. Small structural variations in the material single out regions that buckle selectively under external stress, whereas other regions remain unchanged. The research is published in this week's early edition of the Proceedings of the National Academy of Sciences.

Unconventional properties

The promise of metamaterials is to realize artificial structures with unusual properties that would be hard to come by in nature. Their unconventional properties can be programmed by suitable design of their geometry or topology. The Leiden researchers created a 3D-printed working prototype of a novel metamaterial that displays selective and tunable buckling.

Topological insulators as inspiration for new mechanical materials

The research was done in the Topological Mechanics Lab (Leiden), led by Vincenzo Vitelli. The lab is fully dedicated to studying the mechanical analogues of so-called "," a recently discovered exotic quantum state of matter. When applied to macroscopic structures, the topological ideas underlying these exotic states give rise to materials with unusual mechanical properties.

Physical 'hunch'

'The design begins with a general idea, a physical 'hunch', based on this analogy,' explains co-author Jayson Paulose. 'The major strength of using these topological ideas in design is that a topological material is guaranteed to have interesting behaviour at the boundaries.'

The next step is to predict the response of the mechanical analogue with the imposed topological design. The ultimate test is to build it and investigate what happens under various kinds of . That resulted in a flexible plastic prototype that displayed the localized buckling response the researchers were looking for. Jayson Paulose: 'We were expecting some trial and error before getting the design to work. But the first batch that we got back from the 3D printing firm worked right out of the box.'

The animation shows successive images of a structure of flexible beams, as it is being compressed into the imaging plane. A subset of the beams in the structure buckle in a coordinated manner. The region of selective buckling is picked out due to a topological characterization of the pattern of beams.

Shape-memory metals

Selective buckling materials have a wide range of potential applications in engineering and medicine. The buckling behaviour can be tuned without changing other physical properties such as electromagnetism or heat conduction. A typical application would be in shape-memory materials, in which shape transitions take place when the temperature is changed. Selective buckling regions in such materials would show dramatically different shape transitions from the rest of the structure, without affecting the heat flow, giving engineers an new possibility to tune such devices.

Researchers design metamaterial that buckles selectively

This research was funded by FOM and the Delta Institute for Theoretical Physics (Delta ITP).

Explore further: Topological protection in mechanical metamaterials

More information: "Selective buckling via states of self-stress in topological metamaterials," Jayson Paulose, Anne Meeussen and Vincenzo Vitelli, PNAS Early Edition, DOI: 10.1073/pnas.1502939112

Related Stories

Topological protection in mechanical metamaterials

January 19, 2015

Researchers at Leiden University, the Netherlands, showed that certain crystal defects in mechanical metamaterials can harbour topologically protected motions. These mechanical states are analogues of protected electronic ...

Topological insulators become a little less 'elusive'

May 12, 2015

They are 'strange' materials, insulators on the inside and conductors on the surface. They also have properties that make them excellent candidates for the development of spintronics ('spin-based electronics') and more in ...

Recommended for you

Pond dwellers called Euglena swim in polygons to avoid light

September 25, 2018

In any seemingly quiet pond the still waters actually teem with tiny pond dwellers called Euglena gracilis. Unseen to the naked eye, the single-celled organism spirals through the water, pulled along a relatively straight ...

Explainer: The US push to boost 'quantum computing'

September 24, 2018

A race by U.S. tech companies to build a new generation of powerful "quantum computers" could get a $1.3 billion boost from Congress, fueled in part by lawmakers' fear of growing competition from China.

A new way to count qubits

September 24, 2018

Researchers at Syracuse University, working with collaborators at the University of Wisconsin (UW)-Madison, have developed a new technique for measuring the state of quantum bits, or qubits, in a quantum computer.

0 comments

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.