Materials Horizons最新文献

Bacterial infection theranostics combining antibacterial therapy and real-time diagnosis can effectively advance the healing process. Near-infrared (NIR) light has been widely utilized for antibacterial photothermal therapy (PTT) and visible light can provide visual cues for the status of treatment, whereas the lack of modulating light propagation hinders the development of high-performance light-based infection theranostics. Here, inspired by the hierarchical micro/nano-structures of panther chameleon skin composed of deep- and superficial-iridophores responsible for regulating NIR and visible light propagation, respectively, a photonic crystal hydrogel is developed for enhanced antibacterial PTT and colorimetric monitoring of pH and treatment temperature. The deep layer composed of large-sized particles in the hyaluronic acid methacryloyl-polyacrylamide hydrogel matrix exhibits a photonic bandgap overlapping NIR light, acting as a universal platform for boosting the photothermal conversion efficiency (PCE) of embedded photothermal agents. As typical examples, 1.75-, 1.80-, and 1.94-fold increases in PCEs are achieved for embedded carbon black, carbon nanotubes, and MXenes, respectively. The superficial layer consisting of small-sized particles and a poly(2-(dimethylamino)ethyl methacrylate) hydrogel matrix is responsible for visible light modulation, exhibiting rapid, high-sensitivity, and broad-range color variations at different pH/temperatures. Benefiting from these light modulation capabilities, high-efficacy and multifunctional bacterial infection theranostics are realized, synergistically facilitating the healing of infected wounds.

Liquid crystal elastomers (LCEs) are a class of smart materials that combine the anisotropic properties of liquid crystals with the elasticity of polymers, enabling reversible metamorphosis (i.e., shape transformation) in response to external stimuli. This reversible metamorphosis makes them ideal for many applications including soft robotics, artificial muscles, sensors, actuators, responsive coatings, etc. Prior studies have designed LCE surfaces with superhydrophobicity (i.e., extreme repellency to high surface tension liquid like water), but the combination of reversible metamorphosis of LCEs with superomniphobicity (i.e., extreme repellency to both high and low surface tension liquids) is unexplored. In this work, we developed LCE-based superomniphobic surfaces with reversible metamorphosis by laser texturing followed by low surface energy surface modification. Our LCE-based superomniphobic surfaces display extreme repellence to both aqueous and organic liquids as well as reversible metamorphosis due to nematic-isotropic transition of LCE. Utilizing these properties, we demonstrated loss-less manipulation of aqueous and organic liquid droplets, enabling merging, mixing, chemical reaction and microfluidic gating. We envision that our LCE-based superomniphobic surfaces with reversible metamorphosis will pave the way towards a wide range of applications including microfluidic reactors, lab-on-chip technologies, adaptive liquid-handling devices, controlled drug delivery systems etc.

The development of high-performance organic photodetectors (OPDs) currently depends on highly toxic halogenated solvents for processing and on an external power source to drive illumination. Here, we report high-sensitivity rigid and flexible self-powered OPDs processed with the environmentally friendly solvent o-xylene. Especially, the flexible OPD achieves a record responsivity of 0.55 A W^-1, along with an ultralow dark current of 0.44 nA cm^-2 and excellent bending stability. By further integrating a mechanoluminescent (ML) unit as a self-powered light source, we demonstrate a ML-OPD sensing system that operates without external power and illumination. Notably, the visible-near infrared broad spectral response of the OPD exhibits a high degree of overlap with ZnS:Cu and other multicolor ML units, ensuring efficient inter-unit optoelectronic energy transform. The ML-OPD system demonstrates dual functionality for real-time motion sensing and gesture recognition by converting mechanical finger flexion/extension (0°-45°) into quantifiable current signals to track continuous motions, while utilizing distinct combinatorial current signatures from multi-finger pattern actuation to execute gesture recognition feedback without visual assistance. This integration of self-powered mechano-optoelectronic transduction establishes a new paradigm for distributed optoelectronic sensing, with future scalability toward multimodal human-machine interaction (HMI) systems requiring ultralow-power operation and spatial adaptability.

Modern advances in high-energy physics have established neutrons as essential probes in scientific research, enabling breakthroughs ranging from high-energy physics, industrial manufacturing, and materials innovation to heritage conservation, medical diagnostics, and geological prospecting. The diminishing supply of ³He gas detectors has increased the demand for cost-efficient alternative neutron-detecting materials. Solid-state glass scintillators demonstrate particular promise due to their low cost, scalable production, and shape adaptability. However, improving their detection efficiency remains challenging due to the structural complexity of glass systems. This review outlines the neutron detection mechanisms and critical performance benchmarks and evaluates recent advances in the development of glass scintillators. Focusing on activator engineering and matrix optimization, we assess the current progress and existing challenges in scintillator performances. We further discuss the innovations in glass fiber device architectures and their emerging applications in neutron imaging. This article concludes with prospects for future research, emphasizing mechanisms, materials engineering, efficiency optimization, and advanced fiber-based detector systems.

Our Emerging Investigator Series features exceptional work by early-career researchers working in the field of materials science.

Natural organisms contain tissues like pearl layers, muscles, and bones with multiscale, multilevel ordered structures, which are challenging for biomimetic material fabrication. This study introduces a versatile method combining cellulose nanocrystal (CNC) shear-induced orientation under fluid forces with DLP 3D printing to create 3D multilevel ordered biomimetic architectures. Using cancellous bone's trabecular branching geometry as a model, a DLP-printed GelMA sacrificial template-complementary to the target structure and enzymatically degradable-was filled with CNC/hyaluronic acid methacrylate (CNC/HAMA) bioink. Within the template's channels, CNCs and HAMA chains oriented along fluid shear forces, forming three-pronged macroscopic architectures mimicking bone trabeculae. Micro/nanoscale analysis showed a Hermans orientation factor of ∼0.76 for CNC/HAMA synergistic alignment, with CNCs achieving ∼70% orientation, enabling ordered nanoscale arrangement. Oriented CNC/HAMA fibers further established microscale order. This approach bridges a complex macroscopic geometry with a 3D cross-scale hierarchical ordered alignment, effectively replicating natural tissues' multilevel structure and enhancing mechanical properties compared to unstructured counterparts. It provides a robust strategy for effectively controlling the 3D molecular orientation within the confined 3D-printed macroscopic structures.

The advancement of dielectric capacitors necessitates dielectric materials that exhibit high energy storage density and superior performance at high temperature. However, current dielectric polymer materials fall short of meeting these criteria. This work pioneers the use of an organic molecular semiconductor as a surface modifier for inorganic fillers. In this work, the inorganic high-ε filler Na_0.5Bi_0.5TiO₃ (NBT) was surface-modified with [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM), an organic molecule semiconductor exhibiting high electron affinity, and subsequently introduced into a polyetherimide (PEI) matrix to fabricate NBT@PCBM/PEI composites. The high-ε NBT enhances the polarization capability of the composites. Meanwhile, the PCBM not only mitigates the problems existing at the interface between inorganic NBT and organic PEI but also acts as a charge trap to restrict charge carrier migration, thereby improving the performance degradation of the composites at high temperature. The results indicate that at room temperature, the 0.2 vol% NBT@PCBM/PEI composites achieved a high energy storage density of 15.17 J cm^-3, exhibiting an improvement of 60% compared to pure PEI. At 150 °C, the 0.2 vol% NBT@PCBM/PEI composites achieved an energy storage density of 9.29 J cm^-3, exhibiting an improvement of 59% compared to pure PEI. It is worth noting that the energy efficiency of the composites in both cases reached more than 90%, which is very beneficial for practical applications. This work provides a feasible way to develop high quality dielectric materials at high temperature.

Sodium-ion batteries have attracted significant attention as efficient energy storage devices to address contemporary energy challenges. The development of high-performance cathode materials is essential for the large-scale application of sodium-ion batteries. Among various cathode materials, Na₄Fe₃(PO₄)₂(P₂O₇), a typical iron-based polyanion compound, is regarded as one of the most promising sodium-ion cathode materials due to its low cost, excellent air stability, and superior electrochemical performance. However, Na₄Fe₃(PO₄)₂(P₂O₇) faces several limitations, including the presence of inert impurities, low intrinsic electrical conductivity, slow Na⁺ diffusion kinetics, and insufficient energy density, all of which significantly restrict its large-scale application. Although considerable progress has been made in Na₄Fe₃(PO₄)₂(P₂O₇) research, particularly over the past decade, a comprehensive and timely review summarizing the advancements in modification strategies, underlying mechanisms, and application prospects is still lacking. This study first investigates the structural framework and sodium storage mechanisms of Na₄Fe₃(PO₄)₂(P₂O₇)-based cathode materials. It then provides a detailed discussion of the current challenges and the corresponding modification strategies and mechanisms. Furthermore, regarding energy density enhancement, the review focuses on Na₄Fe_3-xMn_x(PO₄)₂(P₂O₇), a promising candidate with improved application potential, and discusses the issues arising from the incorporation of Mn, along with proposed solutions. Furthermore, we include a detailed discussion on the prospective applications of NFPP-based cathode materials within the realm of solid-state batteries. Finally, the relationship between NFPP modification research and the practical applications of sodium-ion batteries is emphasized, and potential future research directions for pyrophosphate-based cathode materials in the large-scale deployment of sodium-ion batteries are proposed.

Piezoelectric properties of nanomaterials are often constrained by their intrinsic crystallographic structures. Inspired by spinodal phase separation, this study develops gallium nitride (GaN) spinodoid metamaterials with enhanced and anisotropic piezoelectric properties. Molecular dynamics simulations reveal that these metamaterials exhibit significantly improved piezoelectric stress and strain constants (e.g., d₃₃ enhanced by up to 12 times) and increased piezoelectric anisotropy (e.g., d₃₁ ≠ d₃₂) compared to bulk GaN. These enhancements in piezoelectric performance are strongly affected by their underlying nano-architecture, which is governed by the evolutionary time during spinodal decomposition. Due to the asymmetric topology designs, GaN spinodoid metamaterials can possess more independent non-zero piezoelectric stress/strain constants as well as elastic constants compared to the bulk piezoelectric GaN. Relative density is found to further modulate the piezoelectric properties and anisotropy of the nano-architected piezoelectric materials through the contribution of surface effects and tuning the surface-to-volume ratio. This work underscores the potential of topology engineering to overcome crystallographic constraints in piezoelectric nanomaterials, opening avenues for their applications in nano-energy harvesters and three-dimensional pressure mapping/sensing nano-devices.

Ball milling has emerged as a powerful, solvent-free mechanochemical strategy for precise structural and chemical modification of carbon nanomaterials, offering exceptional control over their architecture, porosity, and surface functionality for advanced electrochemical energy storage. This technique utilizes mechanical energy to drive physical and chemical transformations, enabling critical modifications such as particle size reduction, defect engineering, heteroatom doping (e.g., N, O, S), and pore-structure optimization. For supercapacitors, ball milling facilitates the synthesis of high-performance porous carbons from biomass and coal precursors, yielding materials with high specific surface area, hierarchical pore networks, and abundant functional groups. These characteristics collectively enhance specific capacitance, rate capability, and long-term cycling stability. In lithium-ion batteries (LIBs), ball milling significantly upgrades graphite anodes by introducing defects and heteroatoms, enabling capacities beyond theoretical limits. Moreover, it is instrumental in fabricating robust silicon-carbon composites, where silicon nanoparticles are uniformly embedded in a conductive carbon matrix, effectively mitigating volume expansion and delivering high reversible capacities. Regarding sodium- and potassium-ion batteries (SIBs and PIBs), ball milling proves vital for optimizing hard carbon anodes. It expands interlayer spacing, creates beneficial defects, and refines the microstructure, thereby improving ion diffusion kinetics and storage capacity for the larger Na⁺ and K⁺ ions. This leads to enhanced rate performance and cycling stability. Despite its advantages in scalability, cost-effectiveness, and environmental friendliness, challenges remain in optimizing milling parameters, minimizing undesired side reactions, and ensuring consistency for industrial production. Future research should focus on advanced reactor design, process automation, and the integration of ball milling with complementary techniques to develop next-generation carbon materials for high-performance energy storage devices.