The authors of the study, Jayson Paulose, Bryan Gin-ge Chen and Vincenzo Vitelli, built a prototype of a so-called kagome lattice, named after a well-known Japanese pattern on woven bamboo baskets. In the pattern, hexagons are alternated with triangles. The prototype was made in the lab, and consists of triangles connected by hinges on all three corners. By rearranging the connections in the lattice, the researchers created defects that subtly disrupted the ordered pattern, but did not change the number of connections at any triangle. Two types of defects were realized – one that gave rise to a localized free motion, and one that locally enhanced the rigidity of the lattice.

The underlying mathematical theory was tested with computer simulations, both on a deformed kagome lattice and on a distorted square lattice with comparable defects. By controlling the location and the behaviour of these of topologically protected mechanical motions, the researchers see possibilities for the development of mechanical nano-structures that can be used for molecular robots. The research could also be used for robust information storage. Bits could then be represented by the presence (+) or absence (-) of a protected topological motion at a defect.

The research was done in the Topological Mechanics Lab (Leiden), founded by Vincenzo Vitelli. The lab is part of a new research program that aims to study both theoretically and experimentally the mechanical analogues of topological quantum materials.

Journal reference:

More information: Topological modes bound to dislocations in mechanical metamaterials, Jayson Paulose, Bryan Gin-ge Chen and Vincenzo Vitelli, Nature Physics, 19 Januari 2015 DOI: 10.1038/nphys3185

More about the authors can be found on their websites:

Jayson Paulose

Vincenzo Vitelli

Bryan Gin-ge Chen

Supporting movies can be found at Jayson Paulose's website.