Making metamaterials with sound waves

September 8, 2011—Los Alamos National Laboratory researchers Dipen Sinha, Farid Mitri, and Fernando Garzon of Sensors and Electrochemical Devices have achieved an important step in metamaterials development: they've developed fast and inexpensive tools for engineering these materials.

Metamaterials are engineered materials that gain their unusual properties from structure rather than composition. Metamaterials exhibit exotic properties: they can manipulate electromagnetic and acoustic (sound) waves to create invisibility cloaks, subwavelength focusing, and shielding. The combination of these intriguing properties positions metamaterials to make a significant impact on the technological world.

Until now, metamaterial synthesis was cost-prohibitive and required expensive equipment.

Simple, inexpensive process

The newly developed process uses high-frequency acoustic waves in a resonator cavity to produce a three-dimensional periodic structure. The acoustic waves direct nanoparticles toward the nodes of the standing wave field to form parallel periodic planes within a 3D matrix of epoxy. The particles may consist of any material—metal, insulator, semiconductor, superconductor, piezoelectric, nanowires, nanotubes, or biological materials. A wide variety of patterns and shapes can be created by applying the appropriate ultrasound field.

The journal Review of Scientific Instruments published the research, and numerous scientific websites featured the work. This work supports the Laboratory’s Global Security and Energy Security mission areas and the Materials for the Future science pillar.