Exciting New Material Grows When Stretched
Inspired by the intricate geometries and repetitive patterns found in Islamic art, researchers at Canada’s McGill university have engineered a new kind of stretchable ‘metamaterial’ that when pulled in one direction, expands also in a lateral direction. In other words, when stretched, the material becomes wider, rather than just longer and thinner. Metamaterials then remain stable in their expanded state until they are squeezed back again.
Metamaterials, also referred to as bistable auxetic materials, have their origins in two 1,000 year old tomb towers located in Iran. McGill’s Dr. Ahmad Rafsanjani, also of the Pasini Group, told journalists at the American Physical Society’s March meeting that he used two of the towers’ 70 different architectures — one triangular, the other square — to design this particular auxetic material that expands in all directions.
Making these reversible changes possible within the material are small sections that rotate as the rubber is stretched. These rotating units (seen in colour both above and in this movie) have been used in many similar types of metamaterials. But what is unique about this metamaterial is the way it snaps between different configurations. “These designs are easier to fabricate; all you need is a laser cutter,” explains Dr. Rafsanjani.
These materials have potentially very interesting application in the medical field, expandable stents in particular, as well as in the space industry.
You can see these incredible metamaterials in full action here.
Source: BBC News