Aug 2026· Small Methods· pp.
e70993
· 0 citations· 34 references
Medicine
Abstract
Physically unclonable functions (PUFs) provide hardware-rooted security by converting intrinsic material randomness into unique cryptographic fingerprints. However, most existing PUF systems rely on a single entropy source, limiting key capacity and adaptability for hierarchical authentication. Here, we report a hierarchical PUF architecture based on two-dimensional high-entropy spinel oxide (CoCrFeMnNi)3O4 nanoflakes synthesized by molecular sieve-assisted chemical vapor deposition. The triangular nanoflakes exhibit two energetically degenerate in-plane orientations that can be used for rapid, low-cost key extraction. This kind of PUF demonstrates excellent cryptographic characteristics with near-ideal bit uniformity, high inter-device uniqueness, and strong resistance to environmental perturbations including illumination variation, thermal treatment, and chemical exposure. Meanwhile, the stochastic occupation of lattice sites by multiple metal cations within the high-entropy structure produces atomic-scale compositional fluctuations, which provides a second, high-density entropy source. The elemental intensity fluctuations are further processed through permutation and multi-element encoding to generate cryptographic keys with extremely large capacity. By integrating independent entropy channels at different structural scales within a single material system, this work establishes a materials-centric strategy for hierarchical and intrinsically unclonable hardware security, offering a scalable platform for next-generation Internet-of-Things and edge-computing authentication technologies.
In an era marked by increasing demand for advanced anticounterfeiting measures, we introduce a four-dimensional (4D) dynamic physical unclonable function that uses defect-engineered photoluminescence blinking in all-inorganic CsPbBr3 perovskite quantum dots (QDs) embedded within a polymethylmethacrylate matrix. Even within a single z-axis layer, this system achieves an unprecedented theoretical encoding capacity of more than 10216,742, while each device can generate up to 25 billion distinct codes. The QDs exhibit stochastic transitions between emissive and nonemissive states, enabling binary encoding across both spatial and temporal dimensions. The mechanism reveals that surface lead interstitials predominantly mediate nonradiative Auger recombination, whereas cesium vacancies act as effective Shockley-Read-Hall recombination centers, jointly governing the blinking of CsPbBr3. Alkali metal doping modulates this blinking behavior, providing precise control over the emission dynamics. Practical utility is demonstrated through a dual-mode authentication strategy that enables rapid field verification via standard smartphones while retaining high-security 4D verification via microscopy. We further establish a spatial-temporal dual-model authentication framework that integrates convolutional neural network (CNN)–based spatial matching with a temporal-branch dynamic check and decision-fusion assessment. The framework resists 14 adversarial attacks spanning replay, impersonation, temporal and local manipulation, Z-stack modification, projection forgery, and synthetic forgery attack, showing robust sequence-level security beyond frame-level CNN recognition. This work transforms what was once considered a detrimental phenomenon—QD blinking—into a valuable asset for dynamic, high-capacity encryption, opening new avenues for ultrasecure cryptographic systems.
Counterfeiting remains a persistent global challenge, necessitating security technologies that combine robust unclonability with rapid, field-verifiable accessibility. Conventional optical labels with uniform designs are easily replicated, while most physical unclonable functions (PUFs) rely on complex fabrication processes or specialized readout systems, limiting their practical deployment, especially considering the broad accessibility of smartphone-based authentication. Here, we report a materials-driven strategy that unifies luminescence and physical unclonability through fracture-engineered polymer PUFs. Porous polymer skeletons bearing customized patterns are printed via maskless photolithography and subsequently functionalized by surface-initiated ATRP with Ir-based complexes and fluorescent dyes. This design yields Förster resonance energy transfer (FRET)-enabled, intensity-amplified, and spectrally multiplexed emissions under single-wavelength excitation, enabling optical information encryption and straightforward decoding. Crucially, the porous architecture supports fracture-engineered tape transfer that preserves macroscopic luminescent patterns while spontaneously generating stochastic microscale features at each pixel, producing intrinsically unclonable fingerprints. The resulting mechanically durable tags integrate bright, stable luminescence with reliable PUF characteristics and enable field-readable authentication using only a handheld flashlight and smartphone imaging, without the need for specialized instrumentation. By coupling luminescence with luminescence-enhanced intrinsic PUF security on easily readable tags, this work establishes a versatile and scalable platform for on-site customization and on-demand anti-counterfeiting authentication. Counterfeiting remains a persistent global challenge but most physical unclonable functions (PUFs) rely on complex fabrication processes or specialized readout systems, limiting their practical deployment. Here, the authors report a materials driven strategy that unifies luminescence and physical unclonability through fracture-engineered polymer PUFs.
Shengwei Feng, Li-Peng Qin, Lei Guo et al.· Nature Communications· 0 citations
The precise engineering of nanoscale gaps between discrete building blocks offers a direct pathway to govern charge transport physics in functional materials. Here, we demonstrate a fundamental transition from stochastic bulk conduction to reliable interface-mediated volatile switching by deliberately introducing structural discontinuity in spinel-type Co
3
O
4
nanocube (NC) arrays. While continuous oxide thin films suffer from irreversible breakdown and featureless transport, and disordered NC assemblies exhibit only leakage-like conduction, our self-assembled NC architecture enables a stable and low-power functional response. Utilizing an automated metrology framework based on the Segment Anything Model (SAM), we confirm the formation of a highly ordered, non-percolated square lattice with a narrowly distributed interparticle gap of 2.84 ± 0.64 nm across thousands of junctions. This statistically defined NC-gap-NC junction network confines the active conduction volume to nanoscale junctions, achieving an ultralow operating current of ~ 10 nA and exceptional statistical uniformity (coefficient of variation < 9%); the operating voltage is likewise set by the interparticle junction and can be brought to the ~ 1 V regime by contracting the gap through ligand exchange. Quantitative analysis identifies junction-limited, multi-regime transport across the NC-gap-NC interfaces as the dominant conduction picture, with Schottky-emission-like injection at intermediate fields and Fowler–Nordheim-type field-assisted tunneling at high fields. Furthermore, time-resolved measurements reveal dual-mode relaxation dynamics characterized by microsecond electronic detrapping and slow recovery consistent with ionic back-diffusion, which facilitate complex temporal dynamics for biomimetic signal processing. Our findings suggest that a preformed, statistically quantified nanogap network, rather than bulk percolation, can serve as a useful design principle for energy-efficient electronic primitives beyond conventional continuous media.
Inhyeok Oh, Jun Beom Hwang, Min Seo Kang et al.· Advanced Composites and Hybr...· 0 citations
Conventional ovonic threshold switching (OTS) chalcogenides face a fundamental scaling limit for selector-only memory (SOM), because aggressive thickness scaling increases leakage current and hinders reliable low voltage operation. Here, this trade-off can be overcome by exploiting the unique materials characteristics of the Mg─Te chalcogenide system. Guided by the bonding ionicity map and supported by density functional theory calculations, Mg─Te is identified as an optimal telluride material whose highly ionic bonding is associated with deeper trap levels, a large memory window of 1.75 V, and suppressed leakage in 20 nm devices. Structural analyses and multiscale simulations suggest that the spontaneous phase separation in Mg1Te3 forms MgTe-like ordered nanodomains and Te-rich amorphous regions, providing structural partitioning that may constrain the effective amorphous switching network and reduce stochastic switching variability. With a thin Hf interlayer, the 5 nm Mg1Te3 device achieves narrow SET/RESET switching uniformity of σ = 15/28 mV at ± 2.5 V operating voltage, representative 10 ns programming speed, and write endurance exceeding 1010 cycles in the best-performing device. These results highlight Mg─Te as a promising basis for highly scaled ultralow voltage SOM through the combined roles of ionic bonding, structural partitioning, and interfacial engineering.
Yoori Seo, Dongmin Kim, Y. Park et al.· Advances in Materials· 0 citations
Two-dimensional transition metal dichalcogenides (TMDs) are promising candidates for next-generation neuromorphic electronics owing to their tunable electronic structure and defect-mediated charge dynamics. Here, we demonstrate alloying engineering of Mo1-xWxS2 (0 ≤ x ≤ 1) via chemical vapor deposition to precisely tailor the lattice strain, defect density, and optoelectronic properties. Structural and spectroscopic analyses confirm the homogeneous distribution of Mo and W atoms within the alloy lattice, accompanied by strain fields that enhance trap-mediated charge processes. Optical measurements reveal composition-dependent bandgap tuning and exciton lifetimes, with near-equiatomic MoWS2 exhibiting the strongest non-radiative recombination pathways. Synaptic field-effect transistors based on these alloys display pronounced hysteresis windows of up to 22 V, high interface trap densities, and robust low-frequency noise characteristics, effectively linking alloy disorder to defect-driven memory functions. Remarkably, near-equiatomic MoWS2 synaptic devices emulate key biological features, including a paired-pulse facilitation index of up to 188%, dynamic learning-forgetting-relearning cycles, stable long-term potentiation/depression, and an 87.95% recognition accuracy in CNN simulation. These findings establish alloy-engineered Mo1-xWxS2 as a powerful platform for defect-strain coupling and neuromorphic functionality in two-dimensional materials.
Po-Yu Wei, Chen-Yo Tsai, Chong-Chi Chi et al.· ACS Applied Materials and In...· 0 citations
Physical unclonable functions (PUFs) based on the stochastic optical responses of nanomaterials have emerged as promising hardware security primitives. Their enormous encoding space and inherent randomness produce high-entropy challenge-response characteristics that resist model-based attacks. However, the readout reliability of optical PUFs is susceptible to imaging inconsistencies, including mechanical vibrations and illumination variations. Here, we present a plasmonic PUF system based on spatially disordered gold nanoislands formed by polymer-mediated dewetting. A ConvNeXt-based encoder is trained with combined supervised contrastive, circle, and uniformity losses to achieve an identification accuracy of 99.9%. The resulting embeddings maintain robust discrimination under color perturbations and region-of-interest shifts up to 20%, outperforming traditional direct binarization methods. We further demonstrate the on-chip integration of plasmonic PUFs with both one-time and reusable authentication, highlighting a scalable route toward practical hardware security systems.
