First Metafluid MadeCategory: Science & Technology
Posted: May 11, 2012 03:16PM
A useful consequence of so many of the laws of Nature being mathematical is that there are often ways to manipulate systems to create unusual properties. Metamaterials are an example of this, with their precise electromagnetic properties allowing for optical effects that are not possible with natural materials. As reported by the Helmholtz Association of German Research Centers, researchers at the DFG Center for Functional Nanostructures and the Institute of Applied Physics in Karlsruhe have created the first metafluid, a special kind of metamaterial.
A metafluid is like the metamaterials that create invisibility cloaks, in that they both have precise structures to create special properties; however the special properties of the metafluid are acoustic in nature, not optical. The mechanical behavior of a material is determined by a series of parameters dealing with compression and shear. For example, water's shear parameters are all zero, which is why it flows so well and can be stirred, but its compression parameter is not, hence why we cannot compress water. Creating a material with tailored parameters is like building "a scaffold from pins that must not touch but at their tips."
This first successful acoustic metamaterial is a major accomplishment as it will lead to other metamaterials with very interesting properties. Inaudibility cloaks, acoustic prisms, and new loudspeaker concepts are all examples, but there will likely be more as other researchers get to work.