In a discovery that could reshape how engineers design flexible electronics and durable semiconductor devices, researchers in China have shown that deliberately twisting the atomic layers of bulk van der Waals crystals can make them dramatically more stretchable at room temperature. By introducing controlled interlayer moiré twist angles through a simple off-axis compression process, the team boosted the macroscopic tensile ductility of layered semiconductor crystals by up to 360 percent, achieving tensile strains of roughly 30 percent along the a–b plane. The finding, published in Nature Materials, establishes moiré twisting not merely as a tool for tuning exotic quantum phenomena, but as a practical, broadly applicable mechanism for engineering mechanical resilience into materials that would otherwise shatter under load.
Moiré patterns arise whenever two periodic lattices are overlaid with a slight rotational misalignment, producing a long-wavelength interference superlattice that can profoundly alter electronic behavior. The phenomenon became world-famous with magic-angle twisted bilayer graphene, where twisting two graphene sheets by about 1.1 degrees unleashed unconventional superconductivity. Until now, however, moiré engineering has been pursued almost exclusively as a route to emergent quantum states in atomically thin heterostructures, typically assembled layer by layer under demanding laboratory conditions. The new work demonstrates that the same rotational degree of freedom, when distributed throughout the interior of a bulk crystal, can serve an entirely different purpose: dissipating mechanical stress and preventing catastrophic fracture.
The research team, led by scientists at the Shanghai Institute of Ceramics of the Chinese Academy Sciences together with collaborators at Zhejiang University, concentrated on gallium germanium telluride, GaGeTe, a ternary layered van der Waals semiconductor. Like other van der Waals crystals, GaGeTe consists of robust covalently bonded sheets held together by weak interlayer forces, which allows individual layers to slip relative to one another. In a pristine, perfectly aligned crystal, the layers share a common crystallographic orientation, and under tension the material tends to fail through the initiation and rapid propagation of cracks. The researchers reasoned that if adjacent layers were rotated with respect to each other, the mismatch between their lattices would create moiré superlattices that fundamentally change how stress is accommodated during deformation.
Introducing such twists into a bulk crystal might seem to require assembling it layer by layer, but the team found a remarkably simple route. By applying compression along an axis slightly off the crystal’s principal orientation, they controllably generated interlayer moiré twisting spanning a broad range of angles commensurate with the crystal’s translational symmetry. The magnitude of the twist could be tuned through the degree of pre-compression: samples compressed by 5, 10, and 20 percent developed distinct distributions of twist angles, as revealed by transmission electron microscopy and synchrotron-based diffraction techniques. Three-dimensional precession electron diffraction tomography and Rietveld refinement of synchrotron powder diffraction data confirmed the structural integrity and composition of the treated crystals, while in situ TEM tensile experiments captured the moiré patterns evolving in real time as the material was stretched.
The mechanical consequences were striking. When the pre-compressed, twisted crystals were subsequently pulled in tension at room temperature, their stress–strain curves revealed a transformation from brittle to genuinely ductile behavior. Where untreated GaGeTe fractured after limited elastic and plastic elongation, the twisted crystals sustained tensile strains approaching 30 percent, an increase of up to 360 percent in macroscopic ductility. Critically, the enhancement scaled with the twist angles introduced by compression: higher pre-compression levels produced larger interlayer rotations and correspondingly greater stretchability. The team also verified that the effect persisted across variations in sample thickness and strain rate, underscoring that the mechanism is intrinsic to the twisted architecture rather than an artifact of a particular testing configuration.
The origin of this extraordinary plasticity lies in how moiré superlattices facilitate stress relaxation. Under mechanical loading, the twist angles between neighboring layers continue to increase, allowing the crystal to accommodate deformation through widespread interlayer slipping rather than through the nucleation of fatal cracks. In an untwisted crystal, slipping is constrained by the periodic registry between layers, and once a micro-crack forms, the covalent bonds within a layer offer little resistance to its propagation. In the twisted configuration, the moiré modulation effectively homogenizes and redistributes the interlayer potential energy landscape, lowering the barriers to slip along the basal planes. Density functional theory calculations of generalized stacking fault energies and crystal orbital Hamilton populations supported this picture, showing reduced slip energies and modified Te–Te and Te–Ga bonding along slipping pathways in twisted structures.
Direct atomic-scale imaging told a complementary story. High-angle annular dark-field scanning transmission electron microscopy of deformed samples revealed intralayer bending, ripplocations, and micro-cracks that remained arrested rather than propagating through the entire crystal. In situ TEM tensile videos documented moiré patterns with small twist angles of roughly 1.5 degrees at early deformation stages, growing to approximately 6 degrees as tensile strain accumulated, with the progressive twisting acting as a built-in reservoir for plastic accommodation. The researchers also constructed idealized twist-stacked models, denoted θ-GaGeTe, with alternating layers rotated by specific angles ranging from about 1.5 to nearly 22 degrees; simulated moiré patterns for these structures matched the experimentally observed contrast, validating the structural interpretation of the deformation mechanism.
Perhaps the most important practical feature of the approach is its selectivity. Because moiré twisting occurs only between layers while the atomic arrangement within each layer remains intact, the in-plane electronic properties that make these materials attractive for devices are essentially untouched. This stands in contrast to many toughening strategies that rely on defects, grain boundaries, or alloying, all of which can severely degrade charge transport, optical response, or thermoelectric performance. The authors also demonstrated the generality of the concept beyond GaGeTe: off-axis compression produced comparable enhancements in tensile plasticity across a family of bulk van der Waals crystals including GaS, GaSe, InSe, CrSiTe3, InSiTe3, and SnBi2Te4, suggesting the strategy is broadly applicable to the entire class of layered semiconductors.
The implications reach into several technology areas where mechanical fragility has long limited deployment. Flexible thermoelectrics, which convert waste heat into electricity in conformable formats, depend on semiconductors that can bend and stretch without failing; earlier work by some of the same groups established ductile inorganic semiconductors and exceptional plasticity in materials such as InSe and Bi2Te3-based crystals. The moiré-twisting strategy adds a new, geometrically driven lever to that toolkit, one that is compatible with the demanding electronic requirements of thermoelectric and optoelectronic devices. It may likewise inform the design of two-dimensional-material-based transistors, photodetectors, and silicon photonics components, where GaGeTe itself has recently been integrated into electro-optic devices, by improving the mechanical robustness of bulk crystals used as feedstock or substrates.
From a fundamental standpoint, the study expands the conceptual scope of moiré physics from quantum emergent phenomena to classical mechanics of deformation. It shows that a structural parameter long treated as an electronic tuning knob can double as a mechanical design variable, decoupled from in-plane transport. The work was supported by the National Natural Science Foundation of China, the Chinese Academy of Sciences, and Shanghai municipal programs, with synchrotron experiments performed at the RIKEN BL44B2 beamline of SPring-8 in Japan. As research groups worldwide continue to explore twistronics for superconductivity, magnetism, and correlated electron physics, this result suggests a parallel track: twisting crystals to make them tough. If the strategy can be scaled from laboratory single crystals to manufactured components, the humble rotational misalignment between atomic layers may become one of the most versatile tools in the materials engineer’s repertoire, turning inherently brittle semiconductors into materials that bend, stretch, and survive the demands of real-world flexible technology.
The result also reframes a long-standing dichotomy in materials science. Metals derive their ductility from dislocations, dense arrays of line defects that glide through the crystal lattice and dissipate strain; conventional semiconductors, with their stiff covalent bonding and scarcity of mobile defects, have almost always been relegated to the brittle side of that divide. The moiré-twisting mechanism offers a third route: rather than relying on point or line defects introduced during growth or processing, it exploits a rotational degree of freedom that is deliberately programmed into the stacking sequence itself, effectively designing the deformation pathway in advance.
The approach resonates with recent independent demonstrations that twist can strengthen otherwise fragile solids. Twisted-layer boron nitride ceramics have shown high deformability and strength, and twist-assisted toughening has been reported in two-dimensional transition metal dichalcogenides, indicating that rotational misalignment is emerging as a general design principle spanning scales from atomically thin films to bulk ceramics. The present study extends this principle to ternary van der Waals semiconductors and, crucially, shows that the twist can be introduced after synthesis by a scalable mechanical step rather than during crystal growth.
For practical adoption, the compatibility with existing characterization and processing workflows matters. Off-axis compression requires no epitaxial assembly, no layer-by-layer transfer, and no exotic chemistry, which means the treatment could in principle be applied to crystals grown by conventional bulk methods. Because the twist angles are commensurate with the crystal’s translational symmetry, the resulting superlattices are periodic and well defined, making the deformed crystals amenable to standard diffraction-based quality control before device fabrication.
Open questions remain, including how the twist distributions evolve under cyclic loading, elevated temperature, and long-term operation, and whether the ductility gains persist when crystals are integrated into multilayer device stacks. Answering these will determine whether moiré-twisted semiconductors move from laboratory demonstrations into flexible thermoelectric modules, wearable sensors, and compliant photonic platforms.
Subject of Research: Enhancing tensile plasticity of bulk van der Waals crystals through tunable interlayer moiré twist angles
Article Title: Tuning moiré twist angles enhances tensile plasticity in bulk van der Waals crystals
Article References: Zhou, J., Zou, J., Gao, Z., Zhang, J., Zhang, L., Li, Z., Zhou, Z., Qiu, P., Yang, Y., Yu, Q., Chen, L., & Shi, X. (2026). Tuning moiré twist angles enhances tensile plasticity in bulk van der Waals crystals. Nature Materials. https://doi.org/10.1038/s41563-026-02731-2
Image Credits: AI Generated
DOI: 10.1038/s41563-026-02731-2
Keywords: moiré twisting, van der Waals crystals, tensile ductility, GaGeTe, off-axis compression, plastic deformation, two-dimensional materials, twistronics, semiconductors, flexible electronics, interlayer slipping, Nature Materials
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Denise Maddox. (September 12, 2026). Twisting Crystal Layers Makes Brittle Semiconductors Stretch Like Metals. Scienmag. https://scienmag.com/twisting-crystal-layers-makes-brittle-semiconductors-stretch-like-metals/
Denise Maddox. “Twisting Crystal Layers Makes Brittle Semiconductors Stretch Like Metals.” Scienmag, 12 September 2026, https://scienmag.com/twisting-crystal-layers-makes-brittle-semiconductors-stretch-like-metals/. Accessed 12 September 2026.
Denise Maddox. “Twisting Crystal Layers Makes Brittle Semiconductors Stretch Like Metals.” Scienmag. September 12, 2026. https://scienmag.com/twisting-crystal-layers-makes-brittle-semiconductors-stretch-like-metals/
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Tags: application of moiré superlattices in electronicsdurability of layered semiconductorsflexible electronicsflexible semiconductor devicesGaGeTeimpact of moiré patterns on electronic and mechanical propertiesinterlayer slippinginterlayer twist angles in 2D materialsmechanical resilience in layered materialsmoiré pattern engineering in semiconductorsmoiré twistingNature Materialsoff-axis compressionoff-axis compression techniques in material engineeringplastic deformationquantum phenomena in twisted bilayer materialsroom temperature stretchability of brittle materialssemiconductorstensile ductilitytensile ductility enhancement through twistingtwisted van der Waals crystalstwistronicstwo-dimensional materialsvan der Waals crystals
