A brand new software package developed by researchers at Macquarie University can accurately model the way in which waves — sound, water or light — are scattered after they meet complex configurations of particles.
It will vastly improve the flexibility to rapidly design metamaterials — exciting artificial materials used to amplify, block or deflect waves.
The findings, published within the journal Proceedings of the Royal Society A on 19 June 2024, demonstrated using TMATSOLVER — a multipole-based tool that models interactions between waves and particles of varied shapes and properties.
The TMATSOLVER software makes it very easy to simulate arrangements of as much as several hundred scatterers, even after they have complex shapes.
Lead writer Dr Stuart Hawkins from Macquarie University’s Department of Mathematics and Statistics says the software uses the transition matrix (T-matrix) — a grid of numbers that fully describes how a certain object scatters waves.
“The T-matrix has been used because the Nineteen Sixties, but we have made an enormous step forward in accurately computing the T-matrix for particles much larger than the wavelength, and with complex shapes,” says Dr Hawkins.
“Using TMATSOLVER, we’ve been capable of model configurations of particles that might previously not be addressed.”
Dr Hawkins worked with other mathematicians from the University of Adelaide, in addition to the University of Manchester and Imperial College London, each within the UK, and from the University of Augsburg and University of Bonn, each in Germany.
“It was unbelievable to work on this project and incorporate the TMATSOLVER software into my research on metamaterials,” says Dr Luke Bennetts, a researcher on the University of Adelaide and co-author of the article.
“It meant I could avoid the bottleneck of manufacturing numerical computations to check metamaterial theories and allowed me to simply generalise my test cases to much more complicated geometries.”
Applications in metamaterials
The researchers demonstrated the software’s capabilities through 4 example problems in metamaterial design. These problems included arrays of anisotropic particles, high-contrast square particles, and tuneable [JvE1] periodic structures that decelerate waves.
Metamaterials are designed to have unique properties not present in nature, letting them interact with electromagnetic, sound or other waves by controlling the scale, shape and arrangement of their nanoscale structures.
Examples include super-lenses to view objects on the molecular scale; invisibility cloaks, which refract all visible light; and excellent wave absorption for energy harvesting or noise reduction.
The findings from this research and development of the TMATSOLVER tool may have wide application in accelerating research and development within the growing global marketplace for metamaterials which may be designed for precise wave control.
“We now have shown that our software can compute the T-matrix for a really wide selection of particles, using the techniques most appropriate for the style of particle,” Dr Hawkins says.
“It will enable rapid prototyping and validation of latest metamaterial designs.”
Professor Lucy Marshall, Executive Dean, Faculty of Science and Engineering at Macquarie University, says the software could speed up latest breakthroughs.
“This research represents an enormous step forward in our ability to design and simulate complex metamaterials, and is a primary example of how modern computational methods can drive advancements in materials science and engineering,” says Professor.
