Moiré patterns, familiar as optical illusions when overlapping grids create rippling interference effects, take on a profound significance at the atomic scale. When two lattices of atoms are offset—by rotation or stretching—the resulting moiré geometry can radically alter a material’s physical and electronic behavior. Researchers at the University of Utah have demonstrated that such patterns can be harnessed to design composite materials with properties that shift dramatically depending on the arrangement.
The team’s work, published in *Communications Physics*, extends concepts from both aperiodic geometry and the emerging field of twistronics. Aperiodic geometry describes patterns that never repeat, such as Penrose tiling, which defies translational symmetry. Historical examples include Girih tilings in Islamic architecture, while in materials science, Dan Shechtman’s 1980s discovery of quasicrystals—aperiodic atomic arrangements—earned the 2011 Nobel Prize in Chemistry and reshaped crystallography.
Twistronics, meanwhile, stems from the physics of graphene. Andre Geim and Konstantin Novoselov’s Nobel-winning isolation of graphene in 2010 revealed a single-atom-thick carbon lattice with remarkable strength and conductivity. Subsequent research found that stacking two graphene layers and rotating one slightly could yield superconductivity and other exotic electronic states. This manipulation of twist angle to control properties defines twistronics.
In the Utah study, mathematicians Kenneth Golden, Ben Murphy, David Morison, and Elena Cherkaev applied a similar principle to composites rather than pure atomic layers. They envisioned “twisted bilayer composites” in which two distinct material components—such as a conductor and an insulator—are arranged according to moiré patterns formed by interfering lattices. By twisting or stretching one lattice relative to the other, they could generate ordered, periodic microstructures or aperiodic, seemingly disordered ones.
“As the twist angle and scale parameters vary, these patterns yield myriad microgeometries, with very small changes in the parameters causing very large changes in the material properties,” says Murphy. A mere two-degree twist could transform a periodic, highly conductive arrangement into an aperiodic structure that blocks current entirely. In periodic configurations, the composite behaves like a semiconductor, switching between conductive and non-conductive states. In aperiodic forms, it becomes a robust insulator, akin to tool-handle rubber that prevents electrical shock.
Morison notes that this abrupt conductor-to-insulator transition recalls the Anderson localization phenomenon, which describes how electrons in certain disordered quantum systems can become trapped, halting conduction. That discovery, honored with the 1977 Nobel Prize in Physics, relies on wave scattering and interference. Golden emphasizes that the Utah composites operate on a different principle: “We observe a geometry-driven localization transition that has nothing to do with wave scattering or interference effects, which is a surprising and unexpected discovery.”
The implications for engineering are significant. Because electromagnetic properties vary so sharply with tiny changes in twist angle, designers could precisely tune a composite’s optical response—selecting which wavelengths of light pass through and which are blocked. Cherkaev points out that the mathematical framework extends beyond electrical and optical properties to magnetic, diffusive, and thermal behaviors, and may even apply to acoustic or mechanical analogues.
Such tunability could influence fields from aerospace materials to robotics components, where weight, strength, and conductivity must be balanced with precision. The ability to engineer composites whose performance changes predictably with microstructural geometry opens pathways to adaptive systems, responsive surfaces, and multifunctional parts. The Utah team’s findings reveal that the interplay between geometry and material composition, when guided by moiré interference, offers a versatile toolkit for next-generation material design.