Thermal safety is a fundamental requirement for the application of HMX-based aluminized explosives (HAE) in complex manufacturing and storage scenarios. However, thermal runaway (TR) of HAE encountering unintended aqueous environments with acidic/alkaline additives remains poorly understood, leading to catastrophic incidents. Herein, we combine systematic analyses of heat generation, thermal response behaviors, reaction kinetics, and molecular dynamics (MD) simulations to reveal TR characteristics of confined HAE under dry as well as neutral H2O, acidic, and alkaline aqueous environments. Based on the isothermal cook-off tests, we demonstrate that aqueous exposure substantially lowers apparent activation energy (Ea) and pre-exponential factor (A) in the TR of HAE. Surprisingly, neutral H2O produces the most pronounced reduction, from 321.8 kJ•mol−1 (dry) to 174.1 kJ•mol−1, while acidic and alkaline systems yield intermediate values of 266.0 and 244.3 kJ•mol−1, respectively. Furthermore, accelerating rate calorimetry (ARC) tests confirm that neutral H2O advances the trigger temperature in TR of HAE from 230.2 °C to 205.8 °C. The kinetic compensation effect (KCE) supported by the linear lnA–Ea or enthalpy (ΔH‡)-entropy (ΔS‡) correlations across all four environments, is first extended to the TR regime of HAE. In addition, classical MD shows that mobility of fluorine binder and H2O molecules is enhanced in neutral H2O environments, while reactive MD demonstrates the accelerated Al-F/Al-C bonds formation and Al particle fragmentation, consistent with the increased F/C contents of condensed combustion products (CCPs). Finally, we propose the TR mechanism where crosstalk interactions between Al particles, fluorine binder and H2O facilitate the TR of HAE. These results provide a quantitative kinetic framework and atomistic mechanistic basis for regulating thermal safety of energetic materials in aqueous environments.

Crystal structure evolution of energetic crystals under external stimuli can significantly change their chemical/physical properties and profoundly impact the effectiveness and safety of weapon systems. In this study, the evolution of the crystal structure of the high explosive 1,3,5-trinitro-1,3,5-triazine (Cyclotrimethylenetrinitramine, RDX) is investigated within the temperature range of-100 degrees C-100 degrees C using in situ single-crystal X-ray diffraction technology. The thermal expansion rates of unit cell along the crystal axes and the inter-layer spacings of the mainly exposed crystal planes (111), (210) and (021) are calculated. Compared to the linear expansion of the unit cell, the increase of the atomic thermal vibrations, described by atomic displacement parameter (ADP), of RDX follows an exponential function. The ADP of the nitro group increases much faster than those of the central ring, especially at high temperatures, which is considered to be the cause of the molecular decomposition of RDX, and is consistent with calculation results identifying the-NO2 bond as the trigger of explosive decomposition. A tendency from AAE to AAA conformation is found for the RDX molecule, according to the orientation angle change of the nitro groups relative to the central ring, which causes the compression of the central ring. By comparing the crystal structure evolution behavior of RDX with HMX, it is concluded that the smaller unit cell expansion, the stronger atomic vibration and the lower molecular deformation ability of RDX are not conducive to buffering external energy, which are the main reason for the lower thermal stability, higher mechanical sensitivity and absence of phase transition before thermal decomposition of RDX, compared to HMX. These results will provide a promising way to characterize the crystal structure evolution of energetic materials for the comprehensive understanding of their properties and performance at the atomic and molecular levels. (c) 2025 China Ordnance Society. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Due to the poor mechanical properties of pure silicone rubber, silica is commonly added to enhance its performance. The incorporation of silica alters the irradiation aging process of silicone rubber. This paper analyzes the influence of silica on the irradiation aging behavior of silicone rubber composites from the perspectives of crosslinked network reconstruction and the evolution of filler-matrix interfacial interactions. Irradiation simultaneously breaks the original network and forms a denser one, shifting the crosslinking density distribution from unimodal to bimodal. The evolution of the matrix's crosslinked network is governed by both the strength of the degree of interfacial bonding and the absorbed dose. Specifically, the radiation energy absorbed by the silica filler is locally deposited at the interface region, leading to a significantly higher degree of polymer aging at the interface compared to the bulk matrix. Interfacial strength follows an exponential saturation growth with dose, while total crosslinking density increases linearly. Both the matrix and interfacial aging rates depend on silica content. Based on the inherent difference in the linear attenuation coefficients for γ-rays between SiO₂ and silicone rubber, this study clarifies that a higher filler content leads to greater absorption of radiation energy by the composite. This, in turn, results in faster interfacial aging and overall performance degradation. Thus, this research has, for the first time, quantitatively established a predictive model relating filler content to the aging rate from the perspective of energy absorption.

Crystal structural stability is one of the core indicators for evaluating the safety of energetic materials, since these energetic materials undergo complex environments during manufacturing, processing, transportation, storage, and application in weapon systems. Energetic cocrystals are a novel solid form of energetic materials with unique crystal structures and novel properties. In this study, the crystal structure stability of hexanitrohexoazaisowurtzitane/1-methyl-3,4,5-trinitro-1H-pyrazole (CL-20/MTNP), an energetic cocrystal with high performance, in a water and organic solvent environment (acetone, N,N-dimethylacetamide, dimethyl sulfoxide and ethanol) is characterized. It was found that CL-20/MTNP partially decomposed and transformed to α-CL-20 both in pure water and a mixture of water and organic solvent, as confirmed by powder X-ray diffraction. The decomposition temperature of CL-20/MTNP and residual solid phase in a chemical environment were observed to be significantly different under thermal stimulation. The degree of the decomposition can be controlled by the temperature and soaking time. Unexpectedly, no significant changes were observed for the decomposition behavior after the introduction of organic solvents. Moreover, a polydopamine coating method was also applied to inhibit the decomposition of the cocrystal structure of CL-20/MTNP. These results are of significant reference value for understanding the crystal structure stability of energetic cocrystals and evaluating their safety in practical applications.

The precise modulation of crystallization behavior in poly(vinylidene fluoride-chlorotrifluoroethylene) (P(VDFCTFE))-based composite films via interfacial interactions remains a pivotal challenge for enhancing their functional performance. Here, nitro-functionalized self-assembled monolayers (SAMs) were employed as an effective strategy for interfacial structure modulation. F2314, a VDF/CTFE copolymer with a 1:4 M ratio, was selected as the model system. A well-defined, dense and uniform SAM of 4-nitrothiophenol (PNTP) was fabricated on a gold substrate, which effectively modulated the interfacial interactions and directed the crystallization behavior of F2314. In 20 nm-thick ultrathin films, the nitro-functionalized SAM markedly suppresses flat-on lamellae formation and impedes the growth of edge-on crystalline structures relative to films deposited on bare gold substrates. This suppression of crystallization is attributed to both the disordered surface (5 & Aring;), which fails to provide the crystalline facets necessary for effective nucleation, and the confinement of CTFE units at the SAM/ F2314 interface, where a synergistic combination of weak C-H & sdot;& sdot;& sdot;O hydrogen bonding, dipole-dipole interactions and van der Waals forces collectively impedes the crystallization process. Furthermore, consistent with behavior observed in other polymer systems, the crystallization of ultrathin film is influenced by both temperature and film thickness. Elevated temperatures or reduced film thickness facilitate a reorientation of lamellar structures, transitioning from edge-on to flat-on morphologies.

To enhance the customisation capability of 3D food printing, this study leveraged continuous switching 3D printing and the surimi and beef gels to investigate the mechanism by which soft–hard gel heterostructures influence texture attributes and establish a programmable textural strategy. First, the relationship between the printing process and the consistency of two-phase filaments was examined. Hydrodynamic analysis revealed that the viscoelasticity and the interaction during switching contributed to a reduction in extrusion velocity. Consequently, a variable speed printing strategy was implemented to ensure uniform line width. A patterned printing mode was then employed to precisely control the spatial arrangement of the two slurries, enabling accurate printing of soft-hard gel heterostructures. Furthermore, using voxel structures with varying unit sizes of soft and hard gels as a model system, the influence of gel spatial distribution on texture was studied. Simulation analysis identified that the preferential deformation of soft gel, the skeletal effect of hard gel, and the role of spatial connectivity determine mechanical and textural properties. Based on these insights, interlayer and helix structures were designed to program texture. These architectures endowed the printed products with textural enhancements such as a soft-followed-by-hard texture and improved elasticity.

A comparative investigation was conducted to evaluate the impact of mixing technique (twin-roll milling, internal mixing, and the masterbatch method) on the structure, mechanical properties, thermal stability, electrical conductivity, and thermal conductivity of styrene-butadiene-styrene block copolymer (SBS)/carbon nanotube (CNT) composites. It was found that the incorporation of CNTs enhanced the mechanical, electrical, and thermal conductivity properties of the composites, with negligible effects on thermal stability. The choice of processing method had a pronounced influence on performance, with the samples prepared by twin-roll mixing exhibiting the best properties, while those produced via direct internal mixing demonstrated the lowest performance. Unexpectedly, the masterbatch method did not present advantage in any of the tested performances. Scanning electron microscopy analysis confirmed that CNT dispersion was most uniform in the twin-roll mixed samples. In contrast, large CNT agglomerates were observed in the internal mixed samples. The masterbatch group presented small CNT aggregates, which were produced by breaking the large agglomerates in the masterbatch. Dynamic mechanical analysis indicated that the interfacial interactions between CNTs and SBS were not significantly altered by different processing techniques. Therefore, the performance variations were primarily attributed to differences in CNT dispersion states. These findings present an effective approach for fabricating cost-efficient, high-performance CNT-reinforced elastomer composites and offer valuable insights for practical industrial applications.

High-performance conformal additive manufacturing based on direct ink writing is crucial for the integrated fabrication of multifunctional components on freeform surfaces. However, existing conformal printing processes and toolpath strategies for robot-assisted systems typically rely on direct projection from planar designs. This inherent process limitation leads to critical defects such as insufficient filling and discontinuous infill deposition, severely restricting the practical utility of printed parts. To address these issues, this study proposes a unified conformal toolpath strategy for continuous ink filament filling on complex unstructured curved surfaces. The approach first performs layer-by-layer slicing directly on the substrate surface, resolving self-intersections to obtain curved slicing surfaces. On each slicing surface, isogeodesic filling contours are generated via a heat-field-based method to ensure uniform filament spacing in three-dimensional space. Subsequently, a global continuous path-planning method with embedded lattice structures is developed to simultaneously guarantee deposition continuity and enable process-integrated lattice design. To ensure reliable process execution, the toolpath is further refined by smoothing sharp corners and avoiding potential collisions. Comparative analysis with the traditional projection method demonstrates that the proposed heat-field-based strategy maintains superior consistency in filament spacing. The reliability and conformal quality are further validated by depositing elastomeric structures onto a fingertip, a finger, and a wrist. This work realizes practical conformal manufacturing and lays a solid technical foundation for applications such as humanoid robots, digital gastronomy, circuit repair, and medical orthotics.

Volumetric additive manufacturing (VAM) enables one-step, layer-free fabrication of 3D parts by spatially controlling energy-matter interactions within a photosensitive resin. While VAM is faster than conventional layer-based printing and well suited for complex geometries, wider adoption is limited by coupling between exothermic curing and non-uniform light fields. This interaction degrades surface finish and dimensional accuracy, reducing mechanical and functional performance. Herein, we propose a low-temperature assisted VAM (L-VAM) strategy that tunes resin viscosity via precise temperature-reaction coupling. By stabilizing material flow and mitigating uneven thermal gradients and irradiance disparities, L-VAM suppresses defect formation associated with spatially varying fluidity and heating. Experiments show that an optimized L-VAM process significantly improves dimensional stability and surface quality, delivering a 65.3% reduction in surface roughness compared with conventional VAM. These improvements establish the proposed L-VAM strategy as particularly suitable for high-precision applications including micro-optics and soft robotics.

In addition to their chemical protective role, carbon nanotubes (CNTs) dynamically reconfigure the physical interface with the polymer matrix in silicone rubber during radiation aging. However, the contribution of this physical reinforcement to the macroscopic mechanical behavior remains unclear, hindering the rational design of high-performance materials. To address this, we decouple the microstructural evolution during radiation aging by integrating multi-scale characterization with theoretical modeling. Our analysis reveals that chemical structural changes are not the dominant factor; instead, crosslinking density and filler-matrix physical adsorption constitute the critical bridge linking microscopic interactions to macroscopic performance. Building on this insight, we develop a mechanism-based constitutive model that accurately captures the mechanical response by decomposing the strain energy into damaged and undamaged components. This model establishes deterministic mathematical relationships between its key parameters, radiation dose, and microstructural variables, transforming it into a powerful predictive tool. Our work provides a robust theoretical platform for designing radiation-resistant materials and predicting their service life in extreme environments.

The design and fabrication of superhydrophobic coatings with tunable wettability have significant implications for a wide range of applications, including self-cleaning and anti-icing. Achieving the transition from highadhesion hydrophobic surfaces with the 'rose petal-like effect' to low-adhesion surfaces with the 'lotus effect' through the manipulation of surface microstructures remains a challenge. Hierarchical superhydrophobic surfaces were fabricated using polystyrene (PS) spheres of varying sizes, enabling the wetting transition from the Wenzel state to the Cassie state. The modulation of the size ratio among assembled microspheres enabled a remarkable transition in surface wettability, with the water contact angle increasing from 131.4 degrees to 158.3 degrees and the sliding angle decreasing from 180.0 degrees to 7.3 degrees, demonstrating the evolution from sticky to self-cleaning superhydrophobic states. Computational fluid dynamics (CFD) simulations were employed to elucidate the influence of microsphere size on the variations in contact angle and sliding angle during the construction of superhydrophobic surfaces. By applying uniaxial strain, the contact angle increased from 158.0 degrees to a peak value of 165.0 degrees, eventually reaching a steady state, demonstrating effective strain-induced modulation of surface wettability. This multiscale engineering approach, which integrates structural design with mechanical strain modulation, provides an effective strategy for developing intelligent coatings with adaptive wettability, paving the way for next-generation functional surface coatings.

The formation of stable amorphous phases in rigid organic small molecules is fundamentally hindered by their pronounced crystallization tendency. This challenge is particularly acute in energetic materials, in which the amorphous phase must be stabilized without inert additives to preserve high energy density. Here, we overcome this longstanding obstacle by realising a stable amorphous energetic material based on the small molecule explosive (4,4',5,5'-tetranitro-1H,1'H-2,2'-biimidazole-1,1'-diamine, DATNBI). The amorphous DATNBI (AEM-DATNBI) prepared via a melt quenching process, exhibits a glass transition temperature of 59.67 °C and demonstrates remarkable structural stability below this threshold, maintaining its integrity for over 24 hours at 60 °C. This stability originates from a synergistic interaction between the non-planar molecular framework and a three-dimensional hydrogen-bond network formed by -NH₂/-NO₂ groups. This unique amorphous structure not only enhances safety by suppressing hotspot formation but also accelerates energy release, leading to faster combustion and more complete decomposition. This study demonstrates a general strategy leveraging steric hindrance and intermolecular interactions, thereby extending the realm of amorphous materials to energetic compounds and other functional rigid organic small molecules.

Crystal morphology plays a vital role in the properties and performance of energetic materials (EMs). Here, the crystal morphology of 2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105) grown in dimethyl sulfoxide (DMSO) solution was characterized using single-crystal X-ray diffraction (SCXRD) and rotation imaging techniques. The exposed facets, especially the terminal ones, were indexed for the rod-like LLM-105 crystal for the first time. The preferential growth direction was determined to be the (100) direction. The morphological importance of the crystal planes is in an order of (011) > (020) > (110) > (101) in a lower initial concentration (0.5 mg/mL) and (011) > (020) > (110) in a higher initial concentration (0.8 mg/mL). The increase of concentration was also found to decrease the growth rate along the (001) direction and increase that along the (010) direction. The terminal facets were investigated in more detail to provide the missing piece to our recent knowledge about the crystal morphology of LLM-105. This experimental observation has also been compared with the crystal morphology of LLM-105 predicted by theoretical simulation. The potential reasons for the discrepancy of the theoretical predictions from experimental observations for LLM-105 have been discussed, and actual concentrations, water effects, and dynamic factors were proposed for the improvement of theoretical simulation. A potential strategy for the morphology control of LLM-105 crystals has been proposed. These results clearly demonstrate the central importance of the experimental characterization data to the rationality verification of the growth model in morphology prediction of energetic crystals before practical application and will benefit the morphology control and performance improvement of LLM-105 and other EMs.

Liquid metal (LM) is a promising material for flexible electronics due to its exceptional electrical conductivity and intrinsic flowability. However, persistent challenges hinder the practical implementation of embedding LM in an elastomeric matrix, with concerns about leakage and activation dependency, highlighting the need for advanced composite strategies. Herein, we realize a structural innovation distinct from traditional blended or fully filled composites: the topology-guided, spatially selective integration of LM (Galinstan) within a monolithic elastomer lattice via a single, facile multi-material 3D printing process. The reconfigurable control of spatially selective wettability allows LM to preferentially remain at metallophilic zones while minimizing adhesion in metallophobic zones. Mechanical characterization revealed exceptional cyclic stability with a maximum dynamic recovery capability of approximately 90% for LM. This strategy resolves the mutual constraint between structural (mechanical) and functional (electrical) optimizations inherent in traditional composite methods, decouples the functional role of the LM from the mechanical support of the elastomer, facilitating synergistic LM/elastomer integration and providing significant advantages in terms of electrical stabilization, lightweight design, and leakage prevention. Multifunctional applications, as triboelectric nanogenerator (TENG)-based self-powered sensors and electromagnetic interference (EMI) shielding devices, have been successfully demonstrated. The proposed method would allow LM and elastomers to achieve enhanced structural organization and preserved adaptability simultaneously.

Electronic components are highly susceptible to harsh environmental conditions, underscoring the urgent demand for multifunctional protective materials. In this study, we propose a cryo-polymerization-assisted additive manufacturing technique to fabricate hierarchically porous epoxy frameworks with superior electronic protection capabilities. A room-temperature-processable aqueous ink system incorporating carbon nanofibers and waterborne epoxy is developed, enabling the precise additive manufacturing of 3D lattice structures featuring well-ordered macroscale pores. Subsequent cryo-polymerization process further generates microporous networks within the additively manufactured filaments, yielding a hierarchical architecture with multiscale porosity. This unique structural design endows the resulting composite with remarkable multifunctionality, combining impact absorption (86 %), fracture toughness (1.41 MPam(1/2)), and thermal insulation (0.13 Wm(-1)K-1). The composite maintains over 90 % strength under harsh conditions while demonstrating strong hydrophobicity (water contact angle of 120 degrees) and superior EMI shielding effectiveness (>40 dB). This work establishes a versatile platform for high-performance protective devices and paves the way for next-generation smart materials in advanced electronic protection systems.Electronic components are highly susceptible to harsh environmental conditions, underscoring the urgent demand for multifunctional protective materials. In this study, we propose a cryo-polymerization-assisted additive manufacturing technique to fabricate hierarchically porous epoxy frameworks with superior electronic protection capabilities. A room-temperature-processable aqueous ink system incorporating carbon nanofibers and waterborne epoxy is developed, enabling the precise additive manufacturing of 3D lattice structures featuring well-ordered macroscale pores. Subsequent cryo-polymerization process further generates microporous networks within the additively manufactured filaments, yielding a hierarchical architecture with multiscale porosity. This unique structural design endows the resulting composite with remarkable multifunctionality, combining impact absorption (86 %), fracture toughness (1.41 MPam(1/2)), and thermal insulation (0.13 Wm(-1)K-1). The composite maintains over 90 % strength under harsh conditions while demonstrating strong hydrophobicity (water contact angle of 120 degrees) and superior EMI shielding effectiveness (>40 dB). This work establishes a versatile platform for high-performance protective devices and paves the way for next-generation smart materials in advanced electronic protection systems.

Amorphous materials exhibit a unique combination of properties surpassing crystalline materials due to their disordered structure, opening new dimensions for numerous frontier fields. This state is introduced into energetic materials systems, where the challenge lies not only in constructing stable energetic molecular disordered frameworks; it also faces the dual challenge of coordinated safety and reactivity. Herein, we propose a hydrogen bond-driven molecular assembly strategy using 4,4 ',5,5 '-tetranitro-1H,1 ' H-[2,2 '-biimidazole]-1,1 '-diamine (DATNBI) and hexanitrohexaazaisowurtzitane (CL-20) as model systems. By constructing a 3D hydrogen bond network as a "molecular lock," the stable amorphous DATNBI/CL-20 (AEM-DC) was successfully synthesized. This hydrogen-bond framework effectively constrains molecular motion, forming a kinetic barrier that inhibits crystallization and elevates the crystallization temperature to 101.6 degrees C. The material maintains high reactivity while achieving reduced impact sensitivity (17.5 J) and friction sensitivity (112 N). The material exhibits a combustion duration one to three times shorter and peak pressure 1.5 times higher than crystalline DATNBI, demonstrating synergistically enhanced energy release performance to its crystalline analogues. This result confirms the potential of noncovalent molecular frameworks in stabilizing metastable functional materials, offering a promising strategy for advancing the performance of energetic materials.

Thermal safety is a prerequisite concern for widespread use of explosive crystals encountering unplanned fire conditions. Despite numerous isolated efforts have been devoted to phase transition (PT) and thermal decomposition (TD) of HMX (1,3,5,7-tetrabitro-1,3,5,7-tetrazocane) crystals, while the explicit effects of microstructures in thermal safety remain insufficiently understood, hindering rational design of safer HMX-based energetic materials (EMs). Here, using integrated thermal analysis (differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC)) and small-scale slow cook-off (SSCO) tests as well as combined characterizations (XRD, optical microscopy, SEM, XPS, SAXS, and N2 adsorption), we provide a comprehensive understanding into the defect distribution effects in phase stability and thermal safety of HMX crystals. Through adjusting types and amounts of inorganic acidic/alkali additives in recrystallization process, HMX crystals featuring different distributions in internal and external defects have been harvested. Specifically, acidic additive (HCl) favors the formation of internal defects while alkali additives (NaOH, KOH) prefer the generation of external defects. The phase stability is mainly provoked by external defects. Determined by PT temperature and kinetics parameters, increasing external defects leads to decrease in phase stability. However, increased thermal safety mainly corresponds to decreased internal defects, evidenced by gas pressures and microstructure evolutions in ARC tests and post-bomb debris of SSCO tests. Impressively, TD of HMX crystals with less internal defects boosts the formation of more open porous networks (accessible by N2 gases), facilitating permeation of active gaseous species away from crystals and ultimately improving thermal safety. This study demonstrates the potential of defect engineering strategies in optimizing thermal safety of EMs.

​Ultrafine hexanitrostilbene (HNS) has been widely utilized in detonators due to its advantages in safety and reliability. However, the high surface energy of ultrafine HNS particles leads to solid phase ripening during long-term storage, resulting in an elevated initiation threshold, thereby compromising the reliability. Fluoropolymers are important binders for ultrafine HNS based explosives, which may control the dynamic process solid phase ripening including Ostwald ripening (OR) and Smoluchowski ripening (SR). However, the effects of interaction between fluoropolymers and HNS on solid phase ripening have not been reported. In this work, the effects of poly(vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE: F23-series) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP: F26-series) were investigated. Small-angle X-ray scattering (SAXS) was adopted to investigate the variation of specific surface area (SSA) of ultrafine HNS during thermal aging process. The in situ atomic force microscopy (AFM) was used to observe the morphological changes of ultrafine HNS during ripening. The results show that fluoropolymers can effectively slow down the SSA decrease of ultrafine HNS and restrain the solid phase ripening, which produce a stronger inhibitory effect on SR than OR. The F23-series fluoropolymers show superior ripening inhibition efficiency relative to the F26 series. For example, after aging at 70 °C for 30 days, the SSA of ultrafine HNS, F23-series and F26-series composites with 10 wt% fluoropolymers decreased by 78.08 %, 70.26 % to 70.78 %, and 71.88 % to 73.05 %, respectively. The C-Cl bonds in F23 polymers form stronger interfacial interaction with HNS, which endows F23 series with better anti-ripening performance. This study clarifies the solid phase ripening mechanism of ultrafine HNS-based composite and provides theoretical support for the selection of binders in HNS composite explosives.​

ABSTRACT Ultra‐black materials, characterized by ultrahigh light‐absorption efficiency and black surfaces, have demonstrated tremendous strategic value and application potential in military stealth, aerospace engineering, precision optical instrumentation, and energy conversion. However, their development is currently restricted by an insufficient understanding of the light absorption mechanisms and the lack of systematic design approaches. To address these challenges, this study proposes a comprehensive material‐scene‐characterization ternary research framework and a paradigm evolution model for ultra‐black materials. The fundamental mechanisms underlying ultralow reflectivity, including surface plasmon resonance, light trapping structure, and semiconductor bandgap engineering, were systematically analyzed. Considering the evolution of the research paradigm, a comprehensive overview of representative material systems is provided, covering conventional chemically etched nickel‐phosphorus alloys, carbon nanotubes, emerging top‐down engineered wood structures, and solid‐smoke nanocomposites. This review emphasizes the transformation of characterization techniques from simple reflectivity quantification to multidimensional metrology. Key applications of ultra‐black materials in stray‐light suppression, energy conversion, IR spectral engineering, and auxiliary photocatalysis are discussed. Finally, current challenges and development trends of next‐generation ultra‐black materials are discussed, focusing on artificial intelligence‐assisted inverse design and adaptability to extreme environments. This review aims to provide systematic guidance for the development of next‐generation ultra‐black materials with near‐perfect broadband absorption and outstanding stability.

To elucidate the causes of filament width inconsistency during continuous switching 3D food printing and solve the filament width uniformity issue while maintaining printing accuracy and efficiency. This study first investigated the consistency of filament for beef slurries with varying moisture content under different printing speeds. Furthermore, through rheological analysis, pipe mechanical analysis, and two-phase simulation, the stress state of the slurries during the switching moment in 3D printing was examined, along with variations in phase interface, viscosity, extrusion speed, and pipeline pressure. It was found that the creep behavior during the switching moment, and the friction between the beef slurry and the pipeline resulted in a reduction in extrusion speed during switching, leading to filament inconsistency. Moreover, the interaction behavior between the twophase slurries during flow induced a flow pressure at the two-phase interface, which was identified as the key factor influencing the variation of filament consistency with the slurry properties and printing speed. Based on this, a continuous switching 3D printing technology with real-time speed variation, based on Tcode, was developed. By adjusting the printing speed at the switching moment, the phenomenon of filament width narrowing was avoided, ensuring highly personalized spatial distribution of the two-phase slurries within the printed products and the high-quality construction of voxel structures with 2 mm precision.