By Cameron Chai
A Los Alamos National Lab (LANL) team of researchers has developed a bench-top method using acoustical wave force in order to develop multiple three-dimensional designs that will enable metamaterials and their uses in applications such as invisibility cloaks.
Metamaterials are synthetic materials designed for specific purposes. They imbibe properties including negative refraction to help subwavelength-focusing, negative bulk modulus and band gaps, from their design. The research paper has been published in the Review of Scientific Instruments released by the American Institute of Physics.
The team harnessed the force of an acoustical wave that makes nano-particles group in sporadic motifs within a host liquid that is later turned into solid. The process has been described by Farid Mitri, a Director's Fellow, and member of the Sensors & Electrochemical Devices, Acoustics & Sensors Technology Team, at LANL. The pattern periodicity is convertible and allows for any nanoparticle material to be utilized. Prototypes include metal, insulator, semiconductor, piezoelectric, empty or gas-filled sphere, nanotubes and nanowires.
The structure is created rapidly in 10 seconds to 5 minutes. The team says the method can be utilized for mass production and could create materials exhibiting flexibility in periodicity (mm to nm) and materials used.
The technology will be applicable in invisibility cloaks that will screen objects from radar and sonar sensors, nano- focusing to create high-resolution microscopic lenses and medical ultrasound or optical photo probes, nanoscale directional antennae, anisotropic semiconductors, biological scaffolding, and sensors.