Macroscopic C₅₄₀ mannequin affords new approach to examine sound wave propagation in topological metamaterials

Researchers have taken a novel method to learning the interplay between sure topological metamaterials and sound wave propagation.

The approach, described by IMDEA Supplies’ Dr. Johan Christensen as “cut-and-glue,” was one of many strategies employed within the latest publication “Visualizing the topological pentagon states of a large C₅₄₀ metamaterial” in Nature Communications.

The examine focuses on Buckminsterfullerene, or “buckyballs,” and makes use of 3D printing to scale up the molecular construction of a C₅₄₀ fullerene, which usually has an approximate diameter of round 1.1 nanometer (nm). To place that dimension into perspective, it’s roughly 70,000 occasions smaller than the width of a human hair.

The macroscopic C₅₄₀ mannequin, which contains a community of interwoven hexagons and pentagons, allowed scientists to discover sound wave habits and power confinement in a construction impressed by carbon allotropes, however on a scale giant sufficient to watch immediately.

Fullerenes, or C₆₀, are spherical carbon molecules with 12 pentagonal and 20 hexagonal faces. These molecules have been synthesized by way of laser evaporation and located in uncommon pure supplies corresponding to shungite rocks and carbon-rich stars.

“Whereas fullerenes exhibit distinctive digital properties, observing these properties on the nanoscale is difficult,” defined Dr. Christensen, one of many paper’s authors. “By creating a bigger, 3D-printed C₅₄₀ mannequin, we have been in a position to overcome this limitation, gaining insights into how sound waves work together with the structural defects, often called topological states, inside the carbon lattice.”

The 3D-printed C₅₄₀ construction was made up of hole tubes organized in a community of pentagons and hexagons. This building allows the examine of how sound waves propagate by way of it, with a concentrate on how the pentagonal defects have an effect on wave habits.

“By visualizing these resonant modes, we’re in a position to see how waves work together with topological defects, which is in any other case troublesome to watch in smaller, synthesized molecules,” added Dr. Christensen.

With a view to create the C₅₄₀ mannequin, researchers created after which scaled up a homogenous sheet of graphene, a 2D materials with the thickness of a single atom. They then took benefit of their cut-and-glue approach to chop the sheet into wedges earlier than reattaching them in a soccer ball-like kind to create areas of pressure and curvature inside the construction.

This method mimics the topological defects present in carbon supplies corresponding to graphene and nanotubes. These defects have been identified to affect the habits of digital waves as they journey by way of the fabric, resulting in areas the place waves are confined and behave in distinctive methods.

By manipulating these topological options, researchers demonstrated that they might management wave propagation, which may have important functions in waveguiding, sound insulation, and different acoustic applied sciences.

The following step for researchers will contain analysis into extra complicated fullerene symmetries by way of collaboration with former IMDEA Supplies Visiting Researcher, Prof. Humberto Terrones from Rensselaer Polytechnic Institute.

Researchers included members from IMDEA Supplies and IMDEA Nanoscience, in collaboration with the Supplies Science Institute of Madrid (ICMM-CSIC) and Nanjing College. This partnership will see researchers concentrate on onion multilayer buildings, with a selected curiosity in unlocking new symmetry guidelines by contemplating flexural vibrations as an alternative of sound waves. These outcomes could show related for ultrasonic functions.