Researchers are creating new moiré materials at the nanometer scale using advanced DNA nanotechnology: DNA moiré superlattices form when two periodic DNA lattices are overlaid with a slight rotational twist or positional offset. This creates a new, larger interference pattern with completely different physical properties. A new approach developed by researchers at the University of Stuttgart and the Max Planck Institute for Solid State Research not only facilitates the complex construction of these superlattices; it also unlocks entirely new design possibilities at the nanoscale. The study has been published in the journal Nature Nanotechnology.
Moiré superlattices have become central to modern condensed matter and photonic research. However, realizing such structures typically involves delicate and laborious fabrication steps, including precise alignment and transfer of pre-fabricated layers under highly controlled conditions. “Our approach bypasses traditional constraints of creating moiré superlattices,” says Prof. Laura Na Liu, director of the 2nd Physics Institute at the University of Stuttgart.
New paradigm for the construction of moiré superlattices
“Unlike conventional methods that rely on mechanical stacking and twisting of two-dimensional materials, our platform leverages a bottom-up assembly process,” explains Laura Na Liu. The assembly process refers to the linking of individual DNA strands to form larger, ordered structures. It is based on self-organization: The DNA strands join together without external intervention, solely through molecular interactions. The Stuttgart research team is taking advantage of this special feature. “We encode the geometric parameters of the superlattice — such as rotation angle, sublattice spacing, and lattice symmetry — directly into the molecular design of the initial structure, known as the nucleation seed. We then allow the entire architecture to self-assemble with nanometer precision.” The seed acts as a structural blueprint, directing the hierarchical growth of 2D DNA lattices into precisely twisted bilayers or trilayers, all achieved within a single solution-phase assembly step.
Exploring Uncharted Territory: Moiré Structures on the Intermediate Nanometer Scale
While moiré superlattices have been widely explored at the atomic (angstrom) and photonic (submicron) scales, the intermediate nanometer regime, where both molecular programmability and material functionality converge, has remained largely inaccessible. The Stuttgart researchers have closed this gap with their current study. The team combines two powerful DNA nanotechniques: DNA origami and single-stranded tile (SST) assembly.
Using this hybrid strategy, the researchers constructed micrometer-scale superlattices with unit cell dimensions as small as 2.2 nanometers, featuring tunable twist angles and various lattice symmetries, including square, kagome, and honeycomb. They also demonstrated gradient moiré superlattices, in which the twist angle and hence moiré periodicity varies continuously across the structure. “These superlattices reveal well-defined moiré patterns under transmission electron microscopy, with observed twist angles closely matching those encoded in the DNA origami seed,” notes co-author Prof. Peter A. van Aken from the Max Planck Institute for Solid State Research.
The study also introduces a new growth process for moiré superlattices. The process is initiated by spatially defined capture strands on the DNA seed that act as molecular ‘hooks’ to precisely bind SSTs and direct their interlayer alignment. This enables the controlled formation of twisted bilayers or trilayers with accurately aligned SST sublattices.
Broad implications across molecular engineering, nanophotonics, spintronics, and materials science
Their high spatial resolution, precise addressability, and programmable symmetry endow the new moiré superlattices with significant potential for diverse applications in research and technology. For example, they are ideal scaffolds for nanoscale components — such as fluorescent molecules, metallic nanoparticles or semiconductors in customized 2D and 3D architectures.
When chemically transformed into rigid frameworks, these lattices could be repurposed as phononic crystals or mechanical metamaterials with tunable vibrational responses. Their spatial gradient design also opens avenues for transformation optics and gradient-index photonic devices, where moiré periodicity could steer light or sound along controlled trajectories.
One particularly promising application lies in spin-selective electron transport. DNA has been shown to act as a spin filter, and these well-ordered superlattices with defined moiré symmetries could serve as a platform to explore topological spin transport phenomena in a highly programmable setting.
“This is not about mimicking quantum materials,” says Laura Na Liu. “It’s about expanding the design space and making it possible to build new types of structured matter from the bottom up, with geometric control embedded directly into the molecules.”