Colloidal quasicrystals at optical length scales: assembly, dynamics, and thin-film fabrication

The National Science Foundation Division of Chemical, Bioengineering, Environmental, and Transport Systems awarded $450,000 to the Trustees of The Colorado School of Mines on September 1, 2026, under the Engineering program (CFDA 47.041) to investigate the assembly, dynamics, and thin-film fabrication of colloidal quasicrystals at optical length scales.

The project uses colloids—microscopic particles that model atomic behavior—to observe quasicrystal formation in real time. Quasicrystalline materials are highly ordered but entirely non-repeating, producing unusual optical properties with potential applications in light transmission and laser technologies. Current methods for producing large, high-quality quasicrystals remain unreliable, and most prior research has focused on final atomic structures rather than formation pathways. The work couples electric and magnetic fields to dynamically and reversibly tune interparticle interactions in colloidal suspensions, providing a practical route to quasicrystal assembly. This platform-based approach addresses gaps in understanding quasicrystal nucleation and growth mechanisms while generating training opportunities for early-career scientists.

Performance occurs in Golden, Colorado, with a period of performance running through August 31, 2029. The assistance type is a Project Grant.

Abstract

Materials like metals and salts are formed from repeating atomic patterns that give them a crystalline structure. Quasicrystalline materials are different: they are highly ordered but entirely non-repeating. This unique arrangement gives rise to unusual optical properties with potential applications in light transmission and laser technologies. Realizing these applications, however, requires reliable methods for producing large, high-quality quasicrystals. A deeper understanding of how they form is needed. Most studies have focused on the final structures of atomic materials, providing little insight into the pathways they follow as they form. This project uses colloids to observe quasicrystal formation directly. Colloids are microscopic particles that behave as large-scale models of atoms. Their interactions can be precisely controlled and their assembly monitored with an optical microscope. Therefore, colloids provide an ideal platform for studying the fundamental mechanisms of quasicrystal growth in real time. By uncovering these mechanisms, this project develops strategies for fabricating large quasicrystal domains suitable for optical technologies. The research provides an exceptional platform for training young scientists by allowing them to observe the formation of novel materials as IT happens. This research introduces a field-programmable experimental platform that addresses key gaps in our understanding of quasicrystal formation. While simulations have long shown that quasicrystals can be formed with carefully designed interaction potentials, their experimental realization has remained challenging. This project couples electric and magnetic fields to dynamically and reversibly tune interparticle interactions in standard colloidal suspensions, providing a practical, broadly accessible route to quasicrystal assembly. By constructing quasicrystals from microparticles, this project uniquely enables real-time, particle-resolved visualization of quasiperiodic order using optical microscopy, allowing direct measurement of nucleation pathways, growth kinetics, and stabilization mechanisms across a wide range of effective temperatures and quench rates controlled by the applied fields. A single-component strategy uses orthogonal fields simultaneously to stabilize equilateral square and triangular motifs, thereby enabling quasicrystal formation without engineered multicomponent interactions. The mathematical equivalence of electric and magnetic dipolar interactions implies that the additional electrohydrodynamic effects are a critical, underexplored mechanism in quasicrystal assembly. Identifying and quantifying these contributions advances fundamental understanding of quasiperiodic self-organization and inform broader technologies that leverage electrokinetic flows, including microrobotics and active-matter systems. Finally, the project develops a scalable fabrication process for making thin-film quasicrystals and characterize their optical properties. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are not planned for this award.