Jing Zhang

Submicron-thick (≈0.4 µm) zincophilic CrN coatings on Zn substrate are fabricated by a facile and industry-compatible magnetron sputtering approach. The prepared Zn@CrN anode exhibits high performance and prolonged lifespan due to CrN coatings can effectively suppress the formation of Zn dendrites and the occurrence of side reactions.

Abstract

For exploring advanced Zn-ion batteries (ZIBs) with long lifespan and high Coulombic efficiency (CE), the critically important point is to limit the undesired Zn dendrite and parasitic reactions. Among the coating for electrode is a promising strategy, relying on the trade-off between its thickness and stability to achieve the ultra-stable Zn anodes in ZIBs. Herein, a submicron-thick (≈0.4 µm) zincophilic CrN coatings are fabricated by a facile and industry-compatible magnetron sputtering approach. It is exhilarating that the ultrathin and dense CrN coatings with strong adsorption ability for Zn²⁺ exhibit an impressive lifespan up to 3700 h with ≈100% CE at 1 mA cm⁻². Along with the experiments and theoretical calculations, it is verified that the introduced CrN coatings cannot only effectively suppress the dendrite growth and notorious parasitic reactions, but also allow the uniform Zn deposition due to the reduced nucleation energy. Moreover, the as-assembled Zn@CrN‖MnO₂ full cell delivers a high specific capacity of 171.1 mAh g⁻¹ after 1000 cycles at 1 A g⁻¹, much better than that of Zn‖MnO₂ analog (97.8 mAh g⁻¹). This work provides a facile strategy for scalable fabrication of ultrathin zincophilic coating to push forward the practical applications of ZIBs.

Nature Synthesis, Published online: 27 November 2023; doi:10.1038/s44160-023-00442-z

The unexpected phenomenon of rapid, long-distance transport of an ultrathin and uniform metal film on two-dimensional crystals is reported at temperatures well below the melting points of all of the materials involved. The effect is generalizable and may offer possibilities in confined space chemistry, as well as in two-dimensional crystal growth and devices.

Nature Communications, Published online: 27 November 2023; doi:10.1038/s41467-023-43682-5

Lithium carbonate-promoted mixed rare earth oxides can be used as redox catalysts for OCM at 700 °C and achieve a single-pass C2+ yield up to 30.6%. The high activity is assigned to the peroxide and OH radicals induced by Pr4+ in the redox catalyst.

Emerging super-resolution microscopy methods achieve sub-10 nm resolution, necessitating validation on suitable references structures. Here, a protein-based Imaging Calibration Optical Ruler (PicoRuler) created by site-specific labeling of PCNA through Genetic Code Expansion and bioorthogonal click chemistry is introduced. The interaction among three fluorophores separated by 6 nm can be analysed by photoswitching fingerprint analysis and their distance resolved via DNA-PAINT.

Abstract

Super-resolution microscopy has revolutionized biological imaging enabling direct insight into cellular structures and protein arrangements with so far unmatched spatial resolution. Today, refined single-molecule localization microscopy methods achieve spatial resolutions in the one-digit nanometer range. As the race for molecular resolution fluorescence imaging with visible light continues, reliable biologically compatible reference structures will become essential to validate the resolution power. Here, PicoRulers (protein-based imaging calibration optical rulers), multilabeled oligomeric proteins designed as advanced molecular nanorulers for super-resolution fluorescence imaging are introduced. Genetic code expansion (GCE) is used to site-specifically incorporate three noncanonical amino acids (ncAAs) into the homotrimeric proliferating cell nuclear antigen (PCNA) at 6 nm distances. Bioorthogonal click labeling with tetrazine-dyes and tetrazine-functionalized oligonucleotides allows efficient labeling of the PicoRuler with minimal linkage error. Time-resolved photoswitching fingerprint analysis is used to demonstrate the successful synthesis and DNA-based points accumulation for imaging in nanoscale topography (DNA-PAINT) is used to resolve 6 nm PCNA PicoRulers. Since PicoRulers maintain their structural integrity under cellular conditions they represent ideal molecular nanorulers for benchmarking the performance of super-resolution imaging techniques, particularly in complex biological environments.

This work reports on a novel bottom–up approach, using three atom-long tellurium chains, derived from the dynamic non-equilibrium growth of an a-Si:Te alloy, as building blocks for the self-assembly of monolayer α-tellurene on a Sb₂Te₃ substrate. Atomic-resolution scanning tunneling microscopy demonstrates the hexagonal lattice of α-tellurene.

Abstract

2D materials emerge as a versatile platform for developing next-generation devices. The experimental realization of novel artificial 2D atomic crystals, which does not have bulk counterparts in nature, is still challenging and always requires new physical or chemical processes. Monolayer α-tellurene is predicted to be a stable 2D allotrope of tellurium (Te), which has great potential for applications in high-performance field-effect transistors. However, the synthesis of monolayer α-tellurene remains elusive because of its complex lattice configuration, in which the Te atoms are stacked in tri-layers in an octahedral fashion. Here, a self-assemble approach, using three atom-long Te chains derived from the dynamic non-equilibrium growth of an a-Si:Te alloy as building blocks, is reported for the epitaxial growth of monolayer α-tellurene on a Sb₂Te₃ substrate. By combining scanning tunneling microscopy/spectroscopy with density functional theory calculations, the surface morphology and electronic structure of monolayer α-tellurene are revealed and the underlying growth mechanism is determined. The successful synthesis of monolayer α-tellurene opens up the possibility for the application of this new single-element 2D material in advanced electronic devices.

Nanosegregated fluorescent barcodes offer versatile microsized barcoding with precise spatial control. Crystallization-driven self-assembly enables a 2D polymeric platform for robust barcoding. Rapid assembly kinetics and high compatibility solve encoding complexity, enhancing information storage. Density, scalability, and decoding strategy, expanding fluorescence storage and enabling high-throughput analysis are explored here.

Abstract

The design of nanosegregated fluorescent tags/barcodes by geometrical patterning with precise dimensions and hierarchies could integrate multilevel optical information within one carrier and enhance microsized barcoding techniques for ultrahigh-density optical data storage and encryption. However, precise control of the spatial distribution in micro/nanosized matrices intrinsically limits the accessible barcoding applications in terms of material design and construction. Here, crystallization forces are leveraged to enable a rapid, programmable molecular packing and rapid epitaxial growth of fluorescent units in 2D via crystallization-driven self-assembly. The fluorescence encoding density, scalability, information storage capacity, and decoding techniques of the robust 2D polymeric barcoding platform are explored systematically. These results provide both a theoretical and an experimental foundation for expanding the fluorescence storage capacity, which is a longstanding challenge in state-of-the-art microbarcoding techniques and establish a generalized and adaptable coding platform for high-throughput analysis and optical multiplexing.

Fe₃O₄/La₂O₃ heterostructures in N,O-doped carbon nanospheres are developed via a feasible rare-earth metal oxide engineering tactic. The incorporated La₂O₃ effectively optimize the electronic structure of the Fe d-band center relative to the Fermi level, which results in a significant reduction of the reaction barriers of rate-limiting steps during the ORR in the anion exchange membrane fuel cells.

Abstract

Engineering the electronic configuration and intermediates adsorption behaviors of high-performance non-noble-metal-based catalysts for the sluggish oxygen reduction reaction (ORR) kinetics at the cathode is highly imperative for the development of anion exchange membrane fuel cells (AEMFCs), yet remains an enormous challenge. Herein, a rare-earth metal oxide engineering tactic through the formation of Fe₃O₄/La₂O₃ heterostructures in N,O-doped carbon nanospheres (Fe₃O₄/La₂O₃@N,O-CNSs) for efficient oxygen reduction electrocatalysis is reported. The theoretical calculations reveal that the interfacial bonds formed by the La─O─Fe heterogeneous interface effectively optimize the electronic structure of the Fe d-band center relative to the Fermi level, which results in a significant reduction of the reaction barriers of rate-limiting steps during the ORR. The modulation in intermediates chemisorption enables Fe₃O₄/La₂O₃@N,O-CNSs an outstanding ORR performance and improved stability, with a significantly higher half-wave potential value (0.88 V). More impressively, this integrated catalyst delivers a remarkable power density of 148.7 mW cm⁻² in practical AEMFC operating conditions, along with negligible performance degradation over 100 h using an H₂-air atmosphere, which is higher than commercial Pt/C-coupled electrodes. The results presented here are believed to provide guidelines for fabricating high-performance AEMFCs electrocatalysts in terms of heterointerface engineering and strong electronic coupling effect induced by rare-earth oxides.

Here, high-yield, high-performance, and uniform Ti/MnPS₃/Au memristors are demonstrated to possess the desired characteristics for neuromorphic computing. Microscopic investigation on structural and chemical characteristics of the few-layer MnPS₃ reveals that introduced structural defects and residual Ti can guide the formation of conductive filaments at a low set voltage with minimal variability.

Abstract

While transition-metal thiophosphate (MPX₃) materials have been a subject of extensive research in recent years, experimental studies on MPX₃-based memristors are still in their early stages, with device performance being less than ideal. Here, the successful fabrication of high-yield, high-performance, and uniform memristors are demonstrated to possess desired characteristics for neuromorphic computing using a single-crystalline few-layered manganese phosphorus trisulfide (MnPS₃) as a resistive switching medium. The Ti/MnPS₃/Au memristor exhibits small switching voltage (<1 V), long memory retention (10⁴ s), fast switching speed (≈20 ns), high On/Off ratio (nearly two orders of magnitude), and simultaneously achieves emulation of synaptic weight plasticity. The microscopic investigation of the structural and chemical characteristics of the few-layer MnPS₃ reveals the presence of structural defects and residual Ti throughout the stacked layer following the application of voltage, which contributes to the uniformity of switching with a low set voltage. With highly linear and symmetric analog weight updates coupled with the capability of accurate decimal arithmetic operations, a high accuracy of 95.15% in supervised learning using the MNIST handwritten recognition dataset is achieved in the artificial neural network. Furthermore, convolutional image processing can be implemented using hardware multiply-and-accumulate operation in an experimental memristor crossbar array.

The combination of the low thickness of a 2D material and the magnetic properties of a ferromagnetic element holds great promise for the formation of materials with diverse characteristics applicable in spintronics and multiple other fields. Furthermore, a ferromagnetic element, through the proximity effect, can convert 2D materials into 2D magnets by providing long-lasting magnetic properties.

Abstract

Ferromagnetism in 2D materials has attracted tremendous interest from the scientific community thanks to its potential for the design of magnetic materials with unique properties. The presence of a ferromagnetic element in a 2D material can improve the existing properties and offer new ones, giving rise to the development of manifold applications. This review focuses on recent advances and perspectives of 2D materials that bear at least one ferromagnetic element (iron, cobalt, nickel) as i) structural constituent, ii) dopant atom, or iii) adjacent atom through proximity effect. By describing in detail the magnetic properties that have emerged so far, their potential to form next-generation 2D magnets is discussed. Moreover, the contribution of such 2D materials is analyzed in various applications (electrochemical, photochemical, optical, and electronic), aiming to explore further functionalities and capabilities of ferromagnetic elements, apart from their magnetic nature. Special attention is given to gadolinium and other rare earth elements that display a ferromagnetic order even at ultra-low temperatures and form part of 2D structured materials, with particularly appealing properties deriving from their 4f electrons.

Nature Communications, Published online: 23 November 2023; doi:10.1038/s41467-023-43576-6

Underwater soft robots made of stimuli-responsive shape-changing hydrogels generally present low actuation speed which is limited by the water diffusion between hydrogels and their surrounding environment. Here, the authors develop dynamic hydrogel robots with a fast and switchable actuation based on a thermally driven chain conformation change after mechanical programming.

Nature Communications, Published online: 25 November 2023; doi:10.1038/s41467-023-43483-w

3D social movement capture of large-size mammals is essential for agriculture and life science yet challenging. Here, the authors introduce MAMMAL, an algorithm to enable surface motion captures of multiple freely moving animals and quantitative behaviour measurement in a non-invasive manner.

Nature, Published online: 22 November 2023; doi:10.1038/d41586-023-03502-8

A curious topological structure known as a hopfion ring has been induced in a magnetic material. The first of its kind in 3D, the ring is a tantalizing prospect for several branches of computing development.

Nature, Published online: 22 November 2023; doi:10.1038/s41586-023-06763-5

Imaging of quantum oscillations in Bernal-stacked trilayer graphene with dual gates enables high-precision reconstruction of the highly tunable bands and reveals naturally occurring pseudomagnetic fields as low as 1 mT corresponding to graphene twisting by 1 millidegree.

Nature Electronics, Published online: 23 November 2023; doi:10.1038/s41928-023-01071-2

Memristors based on electric-field-induced phase transitions between a semiconducting and conductive phase of molybdenum ditelluride can be improved by using stressed metal contacts to strain the material closer to the phase switching point.

A plasmon-free SERS probe by a tapered optical fiber coated with monolayer-MoS₂ is demonstrated, where the TOF-supported whispering-gallery modes (WGMs) simultaneously regulate excitonic, molecular and charge-transfer resonance as well as fluorescence resonance energy transfer processes for Raman enhancement with 1.8 × 10⁹-fold for 10^-14 M. The SERS probe demonstrates outstanding feasibility and stability facilitating to trace detection in microdroplets for practical applications.

Abstract

Plasmon-free surface-enhanced Raman spectroscopy (SERS) assisted by charge-transfer (CT) resonance in semiconductors has drawn considerable attention in the past decades due to the extraordinary advantages in chemical stability and homogeneity. Unfortunately, the weak confinement of excitation light in semiconductor nanostructures and 2D materials, due to either their limited refractive indexes or atomic thickness, results in the Raman enhancement by nonmetallic SERS substrates significantly lower than the noble ones. Here a novel plasmon-free SERS probe is reported by a tapered optical fiber (TOF) coated with monolayer-MoS₂ (ML-MoS₂), where the TOF-supported whispering-gallery modes (WGMs) simultaneously regulate multiple-resonance processes, i.e., excitonic resonance, molecular resonance, charge-transfer resonance and fluorescence resonance energy transfer processes, in the ML-MoS₂ and analytes. The contribution of the four processes promoted by WGM to enhancement factor of Raman intensity (EFRI) is quantitatively determined by four dye molecules with different energy levels. The Raman enhancement mechanism of WGM-promoted multiple-resonances is therefore revealed, for the first time. The maximum EFRI is up to 1.8 × 10⁹ for the limit of detection (LoD) down to 10⁻¹⁴ M. The ML-MoS₂/TOF SERS probes also demonstrated their outstanding feasibility and stability facilitating to trace detection in microdroplets for practical applications in future.

The excited-state multi-channel radiative relaxation photophysical processes of excitation-dependent organic chromophores for dynamically regulating polychromic luminescence on a time scale are systematically investigated, and an intelligent rewritable anti-counterfeiting system is established by adopting the cascading processes of “spatial protection- optical trigger- fluorescent multi-level output-time rewriting”, which enables 4D spatiotemporal dynamic regulation multi-level, multi-mode, on-demand encryption/ instantaneous decryption.

Abstract

The efficient collaboration of light tunability and intelligent deformation of fluorescent materials can create an advanced spatiotemporal cascade platform that enables multi-level and multidimensional information storage and encryption. Here, cellulose-based dynamic double-network hydrogels with excitation-dependent (Ex-De) behavior are proposed. The mechanism of multi-channel radiative relaxation and multiple excited state transition of the photoactive component 4′-([2,2′:6′,2″-terpyridin]−4′-yl)-[1,1′-biphenyl]−4-carbaldehyde (TPy-CHO) has been established, and a desirable regulation of excitation energy (wavelength, intensity) on the time scale for multi-level encryption has been achieved. Notably, the dense hydrogen bonds and non-covalent interactions in polymer networks not only enhance the Ex-De behavior, but also provide excellent optical resolution and richer polychromic fluorescence. Even ideal cold white fluorescence is obtained through energy transfer between organic (TPy-CHO) and inorganic (lanthanide ion) hybrid materials. Simultaneously, this unique network structure endows the hydrogel with temperature-mediated self-healing, controllable shape programming behavior and anti-swelling ability, allowing to achieve dynamic multidimensional information encryption capability. The encoded information can reversibly emerge and disappear, allowing for instantaneous on-demand decryption and intelligent re-writability. As a result, a promising multi-level and multidimensional synergistic anti-counterfeiting mechanism is established through the cascade process of “spatial security- light trigger- fluorescence multilevel output-temporal rewriting”.

Hollow microtubular COFs (HT-COFs) with 0.37 nm subnanometer confinement sites are used to confine AIEs. The hollow channel allows easy access to the AIEs, while the interlayers partially trap AIEs, restricting their rotation and aiding the radiative processes. Besides, through exchanging of various AIEs, the versatility of the HT-COFs interlayer as a restriction site is demonstrated.

Abstract

Functionalizing aggregation-induced emission molecules (AIEs) by confining them in porous materials is attracted extensive attention. Here stacked layers of hollow microtubular covalent organic frameworks (HT-COFs) are introduced as sub-nanoconfined sites (0.37 nm) to confine AIEs. The spacious hollow channels allow unimpeded entry for AIEs, while the interlayers perpendicular to the channels partially incarcerate the AIEs within the COFs layers. This effectively restricts the intramolecular rotation of AIEs and facilitates its radiative processes. Through exchanging of various AIEs, the versatility of the COFs interlayer as a restriction site is demonstrated. Furthermore, the sub-nanoconfined fluorescence in AIEs@HT-COFs displays reversible temperature dependence. Based on this, a temperature-tunable fluorescent Micro-QR code device is fabricated, wherein the encoded information disappears at a high-temperature and reemerges at a low-temperature. This work offers novel insights into confined fluorescence within functional materials and the fabrication of AIEs-COF multiplex frameworks.

Digital Fingerprints

In article number 2304432, Hocheon Yoo, Hyun Ho Kim, and co-workers introduce a new physical unclonable function concept using reduced graphene oxide (GO) materials, specifically two types: HGO and PGO. PGO is chemically reduced to achieve a graphene-like state, creating a blend with HGO. This blend, with a conductivity difference of up to 10,000 times, generates a highly unpredictable electrical signal, serving as a secure and unique security key in an optimized physical unclonable function device.

Magnetic fiber robots reveal great potential in minimally invasive surgery. Assembling microtools on curved surfaces of fiber ends is challenging due to their small curvature radii. Herein, a submillimeter fiber robot with integrated micro-manipulation tools is reported using a “Swiss roll” method, allowing one-step assembly on the curved surface. The robot can perform various functions via magnetic manipulation.

Abstract

Magnetic fiber robots have revealed great potential for future minimally invasive robotic surgery. However, with the miniaturization of fiber robots, the integration of functional microtools at the distal end becomes extremely challenging, since it requires assembling multifunctional structures on the curved surfaces of fiber ends, which typically have very small curvature radii. In this study, a submillimeter fiber robot with integrated micro-manipulation tool at the distal end is reported using a “Swiss roll” assembly strategy. This approach enables the one-step assembly of multiscale structures (mm-µm) from a 2D film to a 3D tool on the curved surface of the fiber robot. The multiscale structure consists of a millimeter-scale (mm) magnetic thin film with integrated micrometer-scale (µm) feature structures, which is inspired from the cat tongue covered by numerous little papillae. The fiber robot can perform multiple functions including endovascular clot grabbing, liquid delivery, and sampling under the manipulation of the magnetic field. The strategy provides a universal protocol for integrating and assembling functional components at the distal end of fiber robots, contributing significantly to the functionalization and miniaturization of interventional medical robots.

The search for high-mobility, low-dimensional magnets are usually confined within van der Waals materials. However, their structural clues suggest that these features can also be found in other layered materials with relatively stronger interlayer coupling. Bulk NdSb₂ is presented as a typical example which shows quasi 2D electronic and magnetic properties and can be exfoliated down to few-layer thickness.

Abstract

Advancements in low-dimensional functional device technology heavily rely on the discovery of suitable materials which have interesting physical properties as well as can be exfoliated down to the 2D limit. Exfoliable high-mobility magnets are one such class of materials that, not due to lack of effort, has been limited to only a handful of options. So far, most of the attention has been focused on the van der Waals (vdW) systems. However, even within the non-vdW, layered materials, it is possible to find all these desirable features. Using chemical reasoning, it is found that NdSb₂ is an ideal example. Even with a relatively small interlayer distance, this material can be exfoliated down to few layers. NdSb₂ has an antiferromagnetic ground state with a quasi 2D spin arrangement. The bulk crystals show a very large, non-saturating magnetoresistance along with highly anisotropic electronic transport properties. It is confirmed that this anisotropy originates from the 2D Fermi pockets which also imply a rather quasi 2D confinement of the charge carrier density. Both electron and hole-type carriers show very high mobilities. The possible non-collinear spin arrangement also results in an anomalous Hall effect.

QD-Polymer composites for direct photolithography are of great significance to the development of today's display technology. This review presents representative design strategies for QD-Polymer that can be used for direct photolithography and the development of the direct photolithography process for de-photomasking, which provides guidance for advancing QD-Polymer for high-quality patterning and display applications.

Abstract

For the new display technology based on quantum dots (QDs), achieving high-precision red, green, and blue pixel arrays has always been a research focus in the pursuit of high-quality and vivid image displays. However, problems such as material stability and process environment make it difficult to guarantee the quality of high-precision patterns. The new optical patterning technology represented by direct photolithography is considered a highly promising method for achieving ultrafine patterns at the submicron level. This process prepares patterned quantum dot-polymer films through light-induced chemical changes. This paper reviews the progress of direct photolithography research focused on QD-polymer materials and presents recent advances in such processes for monochromatic/multicolor light patterning. The article classifies QD-polymers into three categories by combining QDs with polymers in different ways, including polymer-coated QDs, polymers as QD ligands, and polymers as photocrosslinkers for QDs. Their synthesis schemes, functional features, and challenges are also presented. In addition, a scheme to remove the photomask during direct lithography using lasers and light field modulation is also proposed. It aims to provide readers and researchers with some generalized research information and improvement ideas. This can further advance the development of direct photolithography for QD-polymers.

Nature Nanotechnology, Published online: 23 November 2023; doi:10.1038/s41565-023-01558-1

Stacking graphene in the rhombohedral order to the tetralayer yields stronger Coulomb interactions, which results in insulating and metallic states with spontaneous symmetry breaking in spin, valley and layer degrees of freedom.

Nature, Published online: 21 November 2023; doi:10.1038/d41586-023-03619-w

Studies find a densely connected network of neurons that communicate over long distances, rather than across synapses.

Erbium (Er)-doped III-V semiconductors are promising for optoelectronic devices due to the unique intra-4f electronic transitions of Er³⁺. This work reports the Er-related photoluminescence from near ultraviolet to near-infrared in ErAs:GaAs grown by molecular beam epitaxy. A carrier-mediated energy transfer up-conversion mechanism is proposed, and the excited-state absorption is confirmed to be governed by a single photonic process.

Abstract

Erbium (Er)-doped III-V semiconductors are promising for optoelectronic devices due to the unique intra-4f electronic transitions of Er³⁺; however, the Er-related luminescence at room temperature has always been challenging to obtain. In this work, High crystalline quality ErAs:GaAs films are grown with self-assembled ErAs nanoparticles embedded within the GaAs matrix by molecular beam epitaxy. Rich photoluminescence spectra in a broad wavelength ranging from near-ultraviolet to near-infrared are observed at room temperature and confirmed to be Er-related. A carrier-mediated energy transfer up-conversion mechanism is proposed, and the pump power-dependent photoluminescence results reveal that the excited-state absorption is governed by a single photonic process. The efficient interaction and energy transfer between the semiconductor matrix and Er³⁺ ions offered by this unique nanocomposite material provide a promising route to achieve novel optoelectronic devices with the potential to cover a broad wavelength range.

Smart micro/nanofiber-based materials capable of monitoring and regulating complicated dynamic healing processes have emerged as the next-generation wound dressings. This review presents a comprehensive summary of smart micro/nanoscale fibrous materials in terms of composition engineering, structural design, and applications in wound healing, and provides the blueprint for the development of smart fibrous materials in wound management.

Abstract

Smart wound dressings capable of detecting, monitoring, and regulating complicated dynamic healing processes hold tremendous potential in wound healing and tissue reconstruction. Micro/nanofiber-based materials are regarded as one of the most promising candidates to develop smart wound dressings owing to their remarkable features including architectural mimicry of extracellular matrix, tunability in structural assembly, and diversity in functionality. Herein, the latest progress of smart micro/nanoscale fiber-based materials in terms of composition engineering, structural design, and applications in wound management is comprehensively reviewed. This work begins with the advances in smart fibers including stimuli-responsive fibers, shape memory fibers, and conductive fibers. Then, the structural design of fiber-based materials from conventional 2D fibrous membrane to emerging 3D fibrous sponge/hydrogel is thoroughly discussed. Furthermore, the applications of smart micro/nanofibrous materials as wound dressings in stimuli-responsive drug delivery, biomechanical stimulation, electrical stimulation, and wound monitoring are highlighted. Finally, the article offers perspectives on the existing challenges and future directions of smart fibrous materials for wound management.

The bionic membranous-wing obtained through heat lamination technology possesses the wing vein and membrane distribution resembling that of the real beetle's hind-wing, exhibiting excellent aerodynamic performance. The integrated multifunctions of bionic intelligent wing in aerodynamics, mechanoreception, and power supply via embodied flapping energy provide a new approach for the design and development of future intelligent flapping-wing micro air vehicles.

Abstract

The mechanoreception system in bionic micro air vehicles, akin to insect sensory neurons, handles internal and external stimulus information. However, current onboard mechanoreception methods add weight and necessitate additional power. Employing the embodied energy design paradigm, a lightweight intelligent membranous wing is proposed, mimicking the scarab beetle's hindwing morphology and kinematics. This wing serves multiple functions, including aerodynamic load-bearing, flight piezo-mechanoreception, and power supply. The beetle's semi-tubular costa structure is replicated, featuring a compliant leading edge for upstroke aerodynamic load resistance. Inspired by beetle hindwing veins and membranes, the bionic wing with three membranous fields: anal, medial, and apical, using heat lamination of multilayer materials is fabricated. The bionic wing's aerodynamic performance closely mirrors that of a real beetle hindwing, enabling various flight maneuvers and validating its real-flight potential. As a piezo-mechanoreception receptor for micro air vehicles, the bionic intelligent wing senses flapping frequency, wing deformations, and collisions through voltage signals from piezoelectric materials in the three membranous fields. Energy harvested from flapping-wing motion powers onboard light intensity and ultraviolet sensors for mobile 3D environmental monitoring. This integration of aerodynamics, mechanoreception, and power supply via embodied flapping energy offers a novel approach for designing future intelligent flapping-wing micro air vehicles.

This paper proposes a modified molten salt assisted exfoliation (MMSAE) strategy to prepare high-quality 2D materials. The MMSAE approach involves using high-frequency disturbance to create a shear force that results in the successful and efficient exfoliation of 2D material. Taking h-BN as an example, an average lateral size of 6.30 µm could be achieved.

Abstract

2D materials hold great promise for numerous applications, and the physical properties of individual 2D materials depend strongly on their thickness and lateral size. Currently, there is a lack of a straightforward method to produce 2D materials with both high-quality and ultra-high aspect ratios. Herein, a modified molten salt-assisted exfoliation (MMSAE) strategy is proposed to prepare high-quality 2D materials with large sizes and controllable thickness. The MMSAE approach involves using high-frequency disturbance to create a shear force that peels off the layers of the intercalated material (e.g., graphene, MoS₂, WS₂, and clays), resulting in the successful and efficient exfoliation of 2D material. Taking h-BN for example, the MMSAE approach achieves the preparation of 2D h-BN with an average lateral size of 6.30 µm, thickness of 2.34 nm, and a high aspect ratio of 2692.

Inspired by tendrils, programmable liquid metal photothermal actuators are prepared via the contraction of polytetrafluoroethylene (PTFE) and the interaction of liquid metal microspheres with polyimide (PI). With finite element analysis (FEA) and programmable morphology, soft robots with various functions are designed. The work provides a new strategy for designing photothermal actuators and sketches a promising future for them in soft robots.

Abstract

Photothermal actuators are widely applied in robots, smart devices, and bionic systems. However, asymmetric thermal expansion, the most common mechanism for preparing photothermal actuators, has not been utilized in programmable liquid metal photothermal actuators. In this work, Liquid metal/Polyimide/Polytetrafluoroethylene (LM/PI/PTFE) programmable photothermal actuators based on asymmetric thermal expansion are prepared inspired by the climbing plant tendrils. The “protoplasm that can contract and bend” PTFE tape endows the photothermal actuator with programmable initial morphology. The photothermal properties and flexibility of the liquid metal microspheres, together with the significant property difference between PI and PTFE, endow the photothermal actuator with excellent response angles (130.74 ± 6.45°), response speeds (46.62 ± 2.33° s⁻¹), stability (2000 cycles for 10 h), and load-carrying capacity, which are not inferior to most of the reported PI photothermal actuators. The LM/PI/PTFE photothermal actuator has been successfully modelled and simulated by finite element analysis (FEA). Based on the programmable initial morphology and the simulation by FEA, this work has designed and prepared a variety of bionic systems and functional robots. The work of LM/PI/PTFE photothermal actuators provides a strategy for designing photothermal actuators and enables the future development of photothermal actuators in bionic systems and robots.