Transistor-based computing faces a fundamental energy-resolution trade-off: lowering the conductance reduces the programming energy (Eprog) but simultaneously narrows the dynamic range (Gmax/Gmin) required for multilevel state discrimination. A memristor offers analog programmability, but it suffers from the same limitation because reducing the conductance decreases Gmax/Gmin, degrading the learning accuracy. Here, a path-decoupled III-V van der Waals (vdW) memtransistor overcomes this constraint via the spatial separation of the ionic and electronic transport pathways. Using HxK1-xGaSb2, K+ vacancies confined to the vdW gap serve as mobile ionic species, while holes conduct within the covalently bonded [GaSb2] layers. This decoupling yields a high K+ diffusivity and enables memristive switching at markedly reduced voltages. The memristive window Gmax/Gmin-which is set by ionic motion-remains invariant under gate modulation, whereas Eprog decreases via electrostatic control of the channel conductance. Consequently, the synaptic plasticity and neuromorphic inference maintain a high accuracy (>80%), while Eprog is reduced by more than an order of magnitude. The results establish ionic-electronic path decoupling as a general strategy for breaking the accuracy-energy trade-off in emerging neuromorphic hardware and position III-V vdW materials, which are promising candidates for application in low-energy, artificial intelligence accelerators.

Atomically sharp interfaces between dissimilar crystal phases are typically achieved through vacuum-based epitaxial growth, whereas solution-based processes generally produce broadened reaction fronts and compositional gradients. Here, we show that wet etching of cation-eutaxy A-III-V compounds unexpectedly yields atomically sharp heterophase interfaces. Using CaGa2P2 as a model system, we demonstrate a composition-driven structural evolution from a stable cation-eutaxy phase to a metastable Ca-deficient cation-eutaxy phase, followed by the emergence of an atomically sharp interface between cation-eutaxy CaGa2P2 and zinc-blende GaP, and culminating in complete conversion to zinc-blende GaP. This behavior arises from the absence of thermodynamically stable intermediate phases, a large mixing enthalpy imposed by coordination mismatch, and strong curvature-driven interface flattening associated with directional III-V covalent bonding. The same transition pathway and atomic scale interface sharpness are reproduced in CaIn2P2 and CaGa2As2, establishing the generality of this mechanism across cation-eutaxy A-III-V compounds. These findings demonstrate that atomic-scale interface control is achievable in diffusion-limited solution processes and motivate future electrical and optical studies of devices exploiting such sharply defined heterophases.

The pursuit of highly flexible and stretchable electronics has generated significant interest in liquid metal (LM) materials due to their remarkable mechanical and electrical properties. However, fully exploiting LM's potential has been hampered by challenges in patterning them at high-resolution and integrating them on a large-scale, thereby limiting their control and practical applications. By modifying the surface of the LM oxide, we introduced sub-10 nm nanomagnets on the LM surface, creating magnetic LM nanohybrid particles (MagLPs). Applying a patterned external magnetic field, we achieved precise assembly of the MagLPs, enabling the high-resolution patterning of LM electrodes at ultrathin thicknesses (∼1 μm). The patterned MagLPs were subsequently transferred onto a stretchable substrate and demonstrated excellent mechanical and electrical characteristics (∼10 000 S/cm). Utilizing a photolithographically fabricated magnetic template, MagLP networks were patterned in wafer-scale production. This technique offers an unconventional engineering approach to the fabrication of stretchable electronics.

Cooperative emission of photons from an ensemble of quantum dots (QDs) as superradiance can arise from the electronically coupled QDs with a coherent emitting excited state. This contrasts with superfluorescence (Dicke superradiance), where the cooperative photon emission requires a buildup of coherence in an ensemble of incoherently excited QDs via their coupling to a common radiation mode. In perovskite QDs, superradiance has been rarely observed, unlike superfluorescence, due to the challenge in QD electronic coupling. Here, we report superradiance with a very narrow linewidth (<5 meV) and a large redshift (∼200 meV) from the strongly coupled CsPbBr3 QD superlattice achieved through the combination of quantum confinement and ligand engineering. The superradiance is polarized in contrast to the uncoupled exciton emission from the same superlattice, indicating anisotropic electronic coupling in superlattices. This finding suggests the potential of a perovskite QD superlattice with structurally controllable interdot coupling as the polarized cooperative photon emitters.

Perpendicular nanochannel creation of two-dimensional (2D) nanostructures requires highly controlled anisotropic drilling processes of the entire structure via void formation. However, chemical approaches for the creation of porosity and defects of 2D nanostructures have been challenging due to the strong basal plane chemical stability and the use of harsh reactants, tending to give randomly corroded 2D structures. In this study, we introduce Lewis acid-base conjugates (LABCs) as molecular drillers with attenuated chemical reactivity which results in the well-defined perpendicular nanochannel formation of 2D TiS2 nanoplates. With the treatment of LABCs, tris(trimethylsilyl)pnictogens (TMS3P or TMS3As), high resolution perforation of TiS2 nanoplates was achieved while maintaining their initial shape and structures. Such perforated TiS2 nanoplates are tunable in their channel diameter between 4 and 10 nm with 2 nm resolution. With their increased surface area and enhanced adsorption of Li2Sx, perforated TiS2 nanoplates served as a diffusion barrier of lithium-sulfur (Li-S) cells, leading to a 2.5-fold improvement in cell performance compared to pristine TiS2 nanoplates. Our molecular design concept for attenuated reactivity of LABCs is simple and could serve as a new approach for chemical drilling processes of 2D metal chalcogenides.

Bioelectronic systems enable label-free monitoring and modulation of cellular activity, providing essential tools for neuroscience and biomedical applications. Nevertheless, many current interfaces are structurally static and lack active positioning capabilities, limiting their adaptability in spatially complex environments. Here, Mag-N-Probe (Magnetically guided Neural-interfacing Probe), a flexible and magnetically actuated bioelectronic system is introduced that enables remote, real-time motion control with sub-micrometer precision and centimeter-scale navigation. The system incorporates ferromagnetic nanoparticles within a pliable mesh framework and utilizes both torque- and gradient force-driven actuation for controlled navigation in confined spaces. This capability permits the repeated targeting of individual neurons for compartment-specific electrophysiological recordings and conformal integration with brain organoids for reliable, multi-channel signal acquisition. By combining magnetic actuation with flexible bioelectronics, Mag-N-Probe provides a versatile and scalable solution for adaptive neural interfacing, applicable to both single-cell studies and 3D tissue environments, thus supporting a wide range of in vitro studies and promising prospects for minimally invasive in vivo applications.

The dynamic mechanical response of tissues underlies their physiological function, yet direct, quantitative measurement of tissue stress in vivo has remained a major challenge. Here, we introduce the mechanoMR microparticle (M3, "M-cube") sensor, a hybrid soft-matter/nanoparticle probe that integrates directly into tissue mechanical networks while transducing local stress into quantitative magnetic resonance (MR) readouts with single-particle resolution. We demonstrate the utility of this platform across diverse model systems, including tumor spheroids, Xenopus embryos, and mouse xenografts, where the M3 sensor enables noninvasive, spatiotemporally resolved mapping of tissue stress dynamics during cancer development. Using this approach, we reveal that epithelial-mesenchymal transition (EMT) is accompanied by distinctive stress-remodeling patterns observable in vivo. Strikingly, we find that abrupt stress increases, rather than cumulative or peak stress magnitude, are the key determinants of EMT induction in cancer cells within the tumor microenvironment. Transcriptomic profiling under controlled stress-loading dynamics shows that sustained yet gradual stress escalation activates cytoprotective antioxidation pathways (e.g., FOXO/AMPK) that reinforce epithelial stability, whereas acute stress surges overwhelm these defense mechanisms, predisposing cells toward mesenchymal reprogramming. These findings establish the M3 sensor as a broadly applicable technology for linking dynamic mechanical cues to cell-state transitions in development, homeostasis, and disease.

The use of the van der Waals (vdW) gap as an ion migration path, similar to cathode materials in lithium-ion batteries, enables improved ion migration. If these materials also possess semiconductor properties, they can simultaneously control electron or hole transport. Such materials can be used in memtransistors, which combine memory and semiconductor characteristics. However, the existing materials rely on defects such as grain boundaries as migration paths, resulting in high ion migration energy barriers and switching voltages. Herein, memtransistors are demonstrated using HxNa2-xIn2As3, which utilizes the vdW gap for ion migration, resulting in lower ion migration energy barriers. It is confirmed that ion migration occurs more readily in the [010] direction in a low-symmetry crystal structure owing to a lower migration energy barrier, whereas migration does not occur in the [100] direction, demonstrating directional dependence. This finding provides crucial guidelines for identifying ion migration in semiconductor materials, which can otherwise be overlooked. The use of the vdW gap as the migration path, variation in migration energy barriers with the ion movement direction, and their impact on low power consumption are critical factors that will guide the future development of memtransistor materials.

Gadolinium (Gd)-based MRI contrast agents are commonly used for T1 imaging but raise safety concerns, including nephrogenic systemic fibrosis and tissue buildup. Conventional iron oxide nanoparticles (IONPs), seen as safer options, often have residual magnetization, causing T2 effects and negative contrast, complicating interpretation. These limitations highlight the need for safer, positive-contrast agents with optimized relaxivity profiles. Here, we report the development of corrugated-surface iron oxide (COSIO) nanoparticles via a two-step seed-conversion strategy involving Fe3S4 intermediates and subsequent oxidative transformation into goethite (α-FeO(OH)). Unlike traditional ultrasmall IONPs, COSIO exhibits substantially reduced magnetization and a corrugated morphology that enhances water-accessible surface area, helping proton exchange. These two effects lower transverse relaxivity (r2) and increase longitudinal relaxivity (r1), respectively, leading to favorable T1 imaging performance. In vivo studies demonstrate that COSIO outperforms a clinical Gd-based contrast agent, Magnevist, in both tumor and cerebral vascular imaging, providing prolonged contrast retention and sharp vascular delineation without nonspecific enhancement. These findings highlight the significance of nanoscale morphological control in developing effective iron-based T1 MRI contrast agents.

Electron beams evolved as important tools for modern technologies that construct and analyze nanoscale architectures. While electron-matter interactions at atomic and macro scales are well-studied, a knowledge gap persists at the molecular to nano level─the scale most relevant to the latest technologies. Here, we employ operando liquid-phase transmission electron microscopy supported by density functional theory calculations and a mathematical random search algorithm to rationalize and quantify electron beam-induced processes at the molecular level. By examining a series of small organic molecules, we identify critical physical and chemical parameters that dictate polymerization rates under continuous electron beam irradiation. Our findings offer a deeper understanding of electron beam-induced reactions, enabling the prediction of molecular reactivities from a classical chemistry perspective. These insights apply equally to other soft matter systems and, thus, are of fundamental interest to scientists and engineers who use electron beams to analyze or to manipulate nanoscale matter.

An encodable DNA clutch with the ability to recognize microenvironmental molecular inputs intelligently complements the remote control of a 200-nm sized magnetic nanomachine. This nanomachine interacts with biological machinery in vitro when the encoded clutch selectively engages the engine with the rotor while external magnetic fields power the rotation.

Machines found in nature and human-made machines share common components, such as an engine, and an output element, such as a rotor, linked by a clutch. This clutch, as seen in biological structures such as dynein, myosin or bacterial flagellar motors, allows for temporary disengagement of the moving parts from the running engine. However, such sophistication is still challenging to achieve in artificial nanomachines. Here we present a spherical rotary nanomotor with a reversible clutch system based on precise molecular recognition of built-in DNA strands. The clutch couples and decouples the engine from the machine's rotor in response to encoded inputs such as DNA or RNA. The nanomotor comprises a porous nanocage as a spherical rotor to confine the magnetic engine particle within the nanospace (∼0.004 μm3) of the cage. Thus, the entropically driven irreversible disintegration of the magnetic engine and the spherical rotor during the disengagement process is eliminated, and an exchange of microenvironmental inputs is possible through the nanopores. Our motor is only 200 nm in size and the clutch-mediated force transmission powered by an embedded ferromagnetic nanocrystal is high enough (∼15.5 pN at 50 mT) for the in vitro mechanical activation of Notch and integrin receptors, demonstrating its potential as nano-bio machinery.

Nanoparticles exhibit distinctive physical and chemical properties that make them effective mediators for optical, magnetic or electric signal transduction. Consequently, nanoparticles are increasingly used in the development of biosensing systems that can detect diseases rapidly and accurately, with potential applications extending to point-of-care settings. In this Review, we discuss key aspects of translating nanoparticles into clinical diagnostics, including particle optimization, device construction and biosensing applications. We focus on two representative particle types; gold nanoparticles and magnetic ferrite nanoparticles, which are widely used in biosensing. We explain the characteristics of these particles and illustrate how they can be tailored to detect various analytical targets such as nucleic acids, proteins and small molecules. Finally, we discuss emerging research directions to advance the clinical integration of nanoparticle assays. Nanoparticles, such as gold nanoparticles and magnetic ferrite nanoparticles, can be applied in biosensors for disease detection. This Review discusses the design of nanoparticles for clinical diagnostics, focusing on their optimization and device construction for the detection of nucleic acids, proteins and small molecules.

Flexible intracortical neural probes have drawn attention for their enhanced longevity in high-resolution neural recordings due to reduced tissue reaction. However, the conventional monolithic fabrication approach has met significant challenges in: (i) scaling the number of recording sites for electrophysiology; (ii) integrating of other physiological sensing and modulation; and (iii) configuring into three-dimensional (3D) shapes for multi-sided electrode arrays. We report an innovative self-assembly technology that allows for implementing flexible origami neural probes as an effective alternative to overcome these challenges. By using magnetic-field-assisted hybrid self-assembly, multiple probes with various modalities can be stacked on top of each other with precise alignment. Using this approach, we demonstrated a multifunctional device with scalable high-density recording sites, dopamine sensors and a temperature sensor integrated on a single flexible probe. Simultaneous large-scale, high-spatial-resolution electrophysiology was demonstrated along with local temperature sensing and dopamine concentration monitoring. A high-density 3D origami probe was assembled by wrapping planar probes around a thin fiber in a diameter of 80∼105 μm using optimal foldable design and capillary force. Directional optogenetic modulation could be achieved with illumination from the neuron-sized micro-LEDs (μLEDs) integrated on the surface of 3D origami probes. We could identify angular heterogeneous single-unit signals and neural connectivity 360° surrounding the probe. The probe longevity was validated by chronic recordings of 64-channel stacked probes in behaving mice for up to 140 days. With the modular, customizable assembly technologies presented, we demonstrated a novel and highly flexible solution to accommodate multifunctional integration, channel scaling, and 3D array configuration.

Novel two-dimensional semiconductor crystals can exhibit diverse physical properties beyond their inherent semiconducting attributes, making their pursuit paramount. Memristive properties, as exemplars of these attributes, are predominantly manifested in wide-bandgap materials. However, simultaneously harnessing semiconductor properties alongside memristive characteristics to produce memtransistors is challenging. Herein we prepared a class of semiconducting III-V-derived van der Waals crystals, specifically the HxA1-xBX form, exhibiting memristive characteristics. To identify candidates for the material synthesis, we conducted a systematic high-throughput screening, leading us to 44 prospective III-V candidates; of these, we successfully synthesized ten, including nitrides, phosphides, arsenides and antimonides. These materials exhibited intriguing characteristics such as electrochemical polarization and memristive phenomena while retaining their semiconductive attributes. We demonstrated the gate-tunable synaptic and logic functions within single-gate memtransistors, capitalizing on the synergistic interplay between the semiconducting and memristive properties of our two-dimensional crystals. Our approach guides the discovery of van der Waals materials with unique properties from unconventional crystal symmetries.

Current soft neural probes are still operated by bulky, rigid electronics mounted to a body, which deteriorate the integrity of the device to biological systems and restrict the free behavior of a subject. We report a soft, conformable neural interface system that can monitor the single-unit activities of neurons with long-term stability. The system implements soft neural probes in the brain, and their subsidiary electronics which are directly printed on the cranial surface. The high-resolution printing of liquid metals forms soft neural probes with a cellular-scale diameter and adaptable lengths. Also, the printing of liquid metal-based circuits and interconnections along the curvature of the cranium enables the conformal integration of electronics to the body, and the cranial circuit delivers neural signals to a smartphone wirelessly. In the in-vivo studies using mice, the system demonstrates long-term recording (33 weeks) of neural activities in arbitrary brain regions. In T-maze behavioral tests, the system shows the behavior-induced activation of neurons in multiple brain regions.

By operando high-resolution transmission electron microscopy, we show that slow secondary electrons from the specimen can demetallate metalloporphyrins. This general approach allows study of the dynamics of various single metal atoms and metal clusters.

Two-dimensional (2D) elemental metals, often overlooked owing to their lack of switching or dielectric properties, have the potential to exhibit unique properties unachievable by their bulk counterparts if their microstructure can be controlled. Here we propose an electrodeposition method that utilizes a confined 2D template to prepare elemental metal nanosheets with an aligned grain orientation, resulting in an exceptionally high in-plane electrical anisotropy of >103. Heterogeneous nucleation is initiated and the directed growth of the metal at the cathode is controlled within a channel whose size is smaller than the critical size of the nuclei. This leads to the formation of anisotropic microstructures, and consequently, the nanosheets exhibit anisotropic electrical properties. Unlike conventional field-effect transistors, devices employing a channel with two orthogonally separated conduction paths yield an exceptional on–off switching ratio exceeding 104. Our approach offers a promising route to produce various 2D elemental metals with properties different from those observed in their bulk counterparts and highlights the potential of anisotropic metallic nanosheets as switching elements. An electrodeposition method is proposed for the growth of elemental metal nanosheets with aligned grain orientation using a confined 2D template. Nucleation and growth are controlled within a confined 2D channel, resulting in nanosheets with high in-plane electrical anisotropy (>103), highlighting their potential as switching elements.

Neuromodulation technologies are crucial for investigating neuronal connectivity and brain function. Magnetic neuromodulation offers wireless and remote deep brain stimulations that are lacking in optogenetic- and wired-electrode-based tools. However, due to the limited understanding of working principles and poorly designed magnetic operating systems, earlier magnetic approaches have yet to be utilized. Furthermore, despite its importance in neuroscience research, cell-type-specific magnetic neuromodulation has remained elusive. Here we present a nanomaterials-based magnetogenetic toolbox, in conjunction with Cre-loxP technology, to selectively activate genetically encoded Piezo1 ion channels in targeted neuronal populations via torque generated by the nanomagnetic actuators in vitro and in vivo. We demonstrate this cell-type-targeting magnetic approach for remote and spatiotemporal precise control of deep brain neural activity in multiple behavioural models, such as bidirectional feeding control, long-term neuromodulation for weight control in obese mice and wireless modulation of social behaviours in multiple mice in the same physical space. Our study demonstrates the potential of cell-type-specific magnetogenetics as an effective and reliable research tool for life sciences, especially in wireless, long-term and freely behaving animals. Minimally invasive cellular-level target-specific neuromodulation is needed to decipher brain function and neural circuitry. Here nano-magnetogenetics using magnetic force actuating nanoparticles has been reported, enabling wireless and remote stimulation of targeted deep brain neurons in freely behaving animals.