Search Results (442)

Surface-enhanced Raman spectroscopy (SERS) amplifies Raman scattering by placing molecules in the near-field of plasmonic nanostructures, enabling label-free molecular fingerprinting. While attractive for living cell phenotyping, many cellular SERS works rely on internalized colloidal nanoparticles, leading to variable uptake/localization, aggregation-driven hotspot fluctuations, and potential cellular perturbation. Here, we report a chip-like Au/SiO₂ nanolaminate SERS substrate that supports direct culture and label-free measurements of living cells on spatially defined hotspots without nanoparticle uptake. The periodic nanolaminate forms dense nanogaps and is engineered for 785 nm excitation, providing uniform enhancement over a large, culture-compatible area with high hotspot uniformity. By engineering the cell–substrate nano–bio interface, the platform enables reproducible acquisition of intrinsic cellular vibrational fingerprints under physiological conditions without Raman tags. Using MCF-7 and MDA-MB-231 breast cancer cells, we collected hundreds of spectra per line, and MDA-MB-231 exhibited broader spectral variations, indicating greater heterogeneity. Principal component analysis and linear discriminant analysis achieved 99% classification accuracy for MCF-7 and MDA-MB-231, and bright-field imaging confirmed preserved adhesion and canonical morphologies. This chip-based, label-free living cell SERS platform enables scalable, nonperturbative phenotyping and may support rapid malignancy classification and treatment response screening across subtle cancer states. Full article

Oil analysis is one of the main means to obtain the working status of important friction pairs in ship and Marine engineering equipment at present. Analyzing the wear mechanism by analyzing the particle size, morphology, properties and other characteristics of metal abrasive particles in the oil is an important basis for achieving health monitoring and scientific maintenance of ship and Marine engineering equipment. Classifying the abrasive particles in the oil according to their particle size is an important step in sample pretreatment. This paper proposes a two-stage sorting microfluidic chip for wear debris based on magnetophoresis. By setting up external permanent magnets in a stepwise manner in the primary and secondary sorting areas, gradient magnetic fields of different magnitudes were formed. The effects of different sample flow rates, sheath fluid flow rates and sheath flow ratios on the pre-focusing before sorting and the sorting effect were studied. The primary sorting of ferromagnetic metal wear particles larger than 50 µm and the secondary sorting of those smaller than 50 µm have been achieved. The primary sorting can serve as an early warning for abnormal equipment wear, while the secondary sorting can provide data support for the scientific formulation of maintenance plans based on equipment requirements. This work provides a new idea and method for the rapid determination of lubricating oil contamination in engineering equipment. Full article

Ti(C,N)-based cermet turning inserts with two distinct chip breaker groove structures were employed to investigate the influence of chip breaker geometry on cutting performance. Chip removal performance and wear resistance of the inserts were evaluated according to chip morphology. The results reveal that, compared with inserts with the V-type groove, those with the SF-type groove exhibit superior chip removal capability and enhanced flank wear resistance. Based on two key parameters of the equivalent groove width and initial chip curl radius, an oblique cutting model was proposed for turning inserts with three-dimensionally complex grooves. The model incorporates the coupled effects of chip breaker geometry, workpiece material properties, inserts material properties and cutting process parameters. By controlling chip morphology, the proposed model effectively realizes the improvement and rational optimization of cutting performance, providing a theoretical basis for the design and optimization of complex groove turning inserts. Full article

Carbon fiber-reinforced thermoplastic composites (CFRTP) are widely used in automotive, aerospace, and other industries due to their lightweight, high specific strength, recyclability, and superior thermal properties. However, their non-homogeneity and anisotropy present challenging machining characteristics, often leading to damage that deteriorates component performance. It is imperative to conduct numerical simulation and experimental studies on CFRTP to systematically analyze the relationship between cutting mechanisms and the surface integrity of CFRTP. This study aimed to establish an innovative three-dimensional micro-scale cutting numerical model that integrates the differentiated constitutive behaviors and damage criteria of carbon fibers, matrices, and fiber–matrix interfaces—enabling precise characterization of micro-scale damage evolution during cutting. By combining simulation with experimental verification, it unveils the material removal mechanisms and processing damage causes of CF/PEEK, and further pioneers the quantification of the gradient correlation between fiber orientations (0°, 45°, 90°, and 135°) and fracture modes, cutting forces, and surface integrity, thereby addressing the gap of micro-mechanism and quantitative analysis in CFRTP machining. The micro-scale damage mechanisms revealed by the model directly reflect the intrinsic response of individual fibers in the tow, and the collective effect of these micro-behaviors determines the macro-scale machining performance observed in the experiments. A right-angle cutting experiment was conducted to validate the accuracy of the micro-scale numerical model. The mechanisms of fiber fracture, damage patterns, and chip morphology were systematically compared. The experimental results demonstrate good agreement with the outcomes of the numerical simulations. This study aims to bridge the gap between theoretical understanding and practical application of the cutting mechanisms in CFRTP, providing valuable insights for advancements in manufacturing processes. Full article

The present study addresses the development and characterization of an in-chip laser-induced graphene (LIG)-based sensor that combines optical and electrochemical transduction techniques as a proof of concept for the advancement of novel point-of-care (POC) devices. In recent years, LIG has emerged as a suitable material for next-generation diagnostic devices due to the increasing need for effective and easily accessible biosensing platforms. In this context, the presented sensors were fabricated and tested with an increasing number of laser exposures to understand how the resulting morphology, degree of graphitization, defects, and electrical resistance of LIG electrodes affect the electrochemical and optical sensing performance. To validate the dual sensor, ferrocyanide ([Fe(CN)₆]⁴⁻) was used as a redox probe and [(4-Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran] (DCM) was used as model dye to explore the electrochemical and optical sensing capabilities. Finally, we showcase the sensor’s ability to perform simultaneous optical and electrochemical on-time detection and analysis of the ferrocyanide electro-oxidation process, underscoring its potential to be used as a dual optical/electrochemical POC device. Full article

The micro-geometry of the cutting edge plays a crucial role in material flow ahead of the cutting edge and chip formation, primarily influencing chip formation mechanisms and the minimum cutting thickness. In the context of turning 304 stainless steel, however, existing research still lacks a unified quantitative framework linking “cutting edge micro-geometry—material separation behavior (separation point/minimum uncut chip thickness)—microstructural evolution of the machined surface.” This gap hampers mechanistic optimization design aimed at enhancing machining quality. This study examines the turning of 304 stainless steel by integrating analytical modeling, finite element simulation, and experimental validation to develop a predictive model for minimum cutting thickness. It analyzes the effects of tool nose radius and asymmetric edge morphology, and a microstructure evolution prediction subroutine is developed based on dislocation density theory. The results indicate that the minimum cutting thickness exhibits a positive correlation with the tool nose radius, and their ratio remains stable within the range of 0.25 to 0.30. Under asymmetric edge conditions, the minimum cutting thickness initially increases and then decreases as the K-factor varies. The developed subroutine, based on the dislocation density model, enables accurate prediction of dislocation density, grain size, and microhardness in the machined surface layer. Among the factors considered, the tool nose radius demonstrates the most pronounced influence on microstructure evolution. This research provides theoretical support and a technical reference for optimizing cutting-edge design and enhancing the machining quality of 304 stainless steel. Full article

Titanium alloys face challenges such as high temperatures, high forces, and tool wear during turning, milling, drilling, and grinding operations. Cryogenic minimum quantity lubrication (CMQL) technology, which combines cryogenic cooling with micro-lubrication, offers an effective solution to these challenges through its synergistic mechanism of heat suppression via cooling and friction reduction via lubrication. This paper first elucidates the cooling and lubrication principles of various CMQL technologies and their adaptability process. It then reviews CMQL applications across four titanium alloy machining processes, systematically analyzing their effects on cutting forces, temperatures, tool wear, surface integrity, and chip morphology. Research indicates that CMQL technology demonstrates universal advantages over minimum quantity lubrication (MQL) across diverse titanium alloy machining processes. Furthermore, incorporating nanofluids or integrating ultrasonic vibration to form enhanced composite processes can further improve medium permeability, reduce machining loads, and enhance surface quality. Future developments in this field will advance toward intelligent and sustainable directions, providing critical technological support for high-performance green manufacturing of titanium alloys. Full article

Dicing is an important process in the packaging segment of the semiconductor manufacturing process, and due to the high hardness and brittleness of 4H-SiC wafers, they are prone to crack propagation and severe chipping during the dicing process. To reduce chipping defects, this study investigates the effects of key process parameters on the chipping behavior of 4H-SiC wafers, as well as the associated chipping formation and material removal mechanisms during dicing. Firstly, a spindle current measurement scheme was designed to indirectly reflect changes in grinding force during the cutting process, and the change in the cutting process in a single pass was analyzed. Secondly, experiments controlling single-factor variables were designed to explore the influence of laws of process parameters, including depth of cut, spindle speed, feed speed, and the dicing blade parameter, abrasive grain size, on the quality of chipping, and the optimal process parameters were obtained. Thirdly, the morphology of the 4H-SiC cutting contact arc area, front–back chipping, and sidewalls was analyzed in order to investigate the chipping formation and material removal mechanism. This study contributes to a fundamental understanding of material removal mechanisms during the cutting of 4H-SiC wafers and other advanced semiconductor materials and provides guidance for optimizing cutting process parameters. Full article

For more than a century, pathology has served as a cornerstone of modern medicine, relying primarily on static microscopic assessment of tissue morphology—such as H&E staining—which remains the “gold standard” for disease diagnosis. However, this conventional paradigm provides only a snapshot of disease states and often fails to capture their dynamic evolution and complex functional mechanisms. Moreover, animal models are constrained by marked interspecies differences, creating a persistent gap in translational research. To overcome these limitations, we propose the concept of New Pathophysiology, a research framework that transcends purely morphological descriptions and aims to resolve functional dynamics in real time. This approach integrates Organ-on-a-Chip (OOC) technology, multi-omics analyses, and artificial intelligence to reconstruct the entire course of disease initiation and to enable personalized medicine. In this review, we first outline the foundations and limitations of traditional pathology and animal models. We then systematically summarize more than one hundred existing OOC disease models across multiple organs—including the kidney, liver, and brain. Finally, we elaborate on how OOC technologies are reshaping the study of key pathological processes such as inflammation, metabolic dysregulation, and fibrosis by converting them into dynamic, mechanistic disease models, and we propose future perspectives in the field. This review adopts a relatively uncommon classification strategy based on pathological mechanisms (mechanism-based), rather than organ-based categorization, allowing readers to recognize shared principles underlying different diseases. Moreover, the focus of this work is not on emphasizing iteration or replacement of existing approaches, but on preserving past achievements from a historical perspective, with an emphasis on overcoming current limitations and enabling new advances. Full article

This study presents a straightforward strategy for producing novel, effective and inexpensive functional non-noble metal-supported carbon materials made from abundant natural biomass. These materials offer a cost-effective alternative to noble metals for the oxidation of hydrazine (HzOR) and demonstrate the potential for widespread adoption of green, energy-saving hydrazine-based technologies in energy applications. Highly efficient and cost-effective iron (Fe) and manganese–iron (MnFe)-supported nitrogen-doped carbon (N–C) materials were developed using hydrothermal synthesis. Meanwhile, the N–C material was obtained from biomass—birch-wood chips—using hydrothermal carbonisation (HTC), followed by activation and nitrogen doping of the resulting hydrochar. The morphology, structure, and composition of the MnFe, MnFe/N–C, and Fe/N–C catalysts were determined using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). The activity of the catalysts for HzOR in an alkaline medium was evaluated using cyclic voltammetry (CV). Depositing MnFe particles onto N–C was shown to significantly enhance electrocatalytic activity for HzOR compared to the Fe/N–C catalyst and especially to the MnFe particles catalyst in terms of highly developed porous structure, which offers the largest surface area, lowest onset potential, and highest current density response, resulting in the strongest catalytic activity. These results suggest that the MnFe/N–C catalyst could be a highly promising anode material for HzOR in direct hydrazine fuel cells (DHFCs). Full article

Epileptic seizures arise from abnormally synchronized neural activity and remain a major global health challenge, affecting more than 50 million people worldwide. Despite advances in pharmacological interventions, a significant proportion of patients continue to experience uncontrolled seizures, underscoring the need for alternative neuromodulation strategies. Rhythmic neural entrainment has recently emerged as a promising mechanism for disrupting pathological synchrony, but most existing systems rely on complex analog electronics or high-power stimulation hardware. This study investigates a proof-of-concept digital custom-designed chip that generates a stable 6 Hz oscillation capable of imposing a stable rhythmic pattern onto digitized seizure-like EEG dynamics. Using a publicly available EEG seizure dataset, we extracted and averaged analog seizure waveforms, digitized them to emulate neural front-ends, and directly interfaced the digitized signals with digital output recordings acquired from the chip using a Saleae Logic analyser. The chip’s pulse train was resampled and low-pass-reconstructed to produce an analog 6 Hz waveform, allowing direct comparison between seizure morphology, its digitized representation, and the entrained output. Frequency-domain and time-domain analyses demonstrate that the chip imposes a narrow-band 6 Hz rhythm that overrides the broadband spectral profile of seizure activity. These results provide a proof-of-concept for low-power digital custom-designed entrainment as a potential pathway toward simplified, wearable neuromodulation device for future healthcare diagnostics. Full article

Organ-on-a-Chip (OOC) platforms are microfluidic systems that recreate key features of human organ physiology in vitro via controlled perfusion. Fluid mechanical stimuli strongly influence cell morphology and function, making this important for cardiovascular OOC applications exposed to pulsatile blood flow. However, many existing OOC devices employ relatively simple chamber geometries and steady inflow assumptions, which may cause non-uniform shear exposure to cells, create stagnant regions with prolonged residence time, and overlook the specific effects of pulsatile perfusion. Here, we used computational fluid dynamics (CFD) to investigate how chamber geometry and inflow conditions shape the near-wall flow environment on a cell culture surface at a matched cycle-averaged volumetric flow rate. Numerical results demonstrated that pillarized chambers markedly reduced relative residence time (RRT) versus the flat chamber, and the small pillar configuration produced the most uniform time-averaged wall shear stress (TAWSS) distribution among the tested designs. Phase-resolved analysis further showed that wall shear stress varies with waveform phase, indicating that steady inflow may not capture features of pulsatile perfusion. These findings provide practical guidance for pillar geometries and perfusion conditions to create more controlled and physiologically relevant microenvironments in OOC platforms, thus improving the reliability of cell experimental readouts. Full article

Micro- and nanoplastics (MNPs) are increasingly recognized as pervasive environmental contaminants with profound implications for ecosystems and human health. Their small size, compositional diversity, and occurrence across complex matrices—including water, soil, food, and biological samples—pose substantial analytical challenges. Conventional techniques such as vibrational spectroscopy, chromatographic analysis, and electron microscopy have yielded critical insights into MNP composition, morphology, and distribution; however, these methods often face limitations in sensitivity, throughput, and adaptability to real-world samples. Recent advances in nanotechnology have catalyzed the emergence of nanodevices—encompassing nanosensors, nanopore systems, integrated lab-on-a-chip platforms and nanostructured capture materials—that promise enhanced sensitivity, specificity, and the capacity for real-time, in situ detection. These innovations not only facilitate high-throughput analysis but also provide novel opportunities for integrated characterization of MNPs across diverse matrices. This review synthesizes the current state of nanodevice-based MNP detection, critically examining their principles, performance, and limitations relative to conventional approaches, and outlining the key needs for standardization, matrix-specific adaptation, and regulatory harmonization. Full article

Mn⁴⁺-activated fluoride phosphors possess outstanding luminescent properties, making them highly suitable for applications in lighting and display technologies. However, the synthesis of such phosphors generally requires the use of large amounts of highly toxic aqueous HF, leading to serious environmental pollution. To eliminate the use of hazardous HF solution, a low-temperature molten salt method employing NH₄HF₂ was developed to synthesize the narrow-band red emitter Cs₂GeF₆: Mn⁴⁺ phosphor. Following the reaction, the product was washed with a dilute H₂O₂ solution to remove residual NH₄HF₂ and other impurities. The phase purity and morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively, and the luminescence properties were examined via photoluminescence (PL) spectroscopy. The obtained phosphors exhibit bright red emission characteristics of Mn⁴⁺ under blue-violet excitation. Among them, Cs₂GeF₆: 0.08 Mn⁴⁺ shows the highest emission intensity, with an internal quantum efficiency (IQE) of 78%. A white light-emitting diode (WLED) fabricated by combining this phosphor with a blue chip and commercial Y₃Al₅O₁₂: Ce³⁺ (YAG) phosphor achieved a high luminous efficacy (LE) of ~146 lm/W, a correlated color temperature (CCT) of ~4396 K, and a color rendering index (Ra) of ~83, alongside excellent operational color stability. Full article

Carbon fiber reinforced silicon carbide (C/SiC) composite material exhibits exceptional properties, including high strength, high stiffness, low density, outstanding high-temperature performance, and corrosion resistance. Consequently, they are widely used in aerospace, defense, and automotive engineering. However, their anisotropic, high hardness, and brittle characteristics make them a typical difficult-to-machine material. This paper focuses on achieving high-quality micro hole machining of C/SiC composite material via electrical discharge machining. It systematically investigates electrical discharge machining characteristics and innovatively develops a hollow internal flow helical electrode reaming process. Experimental results reveal four typical chip morphologies: spherical, columnar, blocky, and molten. The study uncovers a multi-mechanism cutting process: the EDM ablation of the composite involves material melting and explosive vaporization, the intact extraction and fracture of carbon fibers, and the brittle fracture and spalling of the SiC matrix. Discharge energy correlates closely with surface roughness: higher energy removes more SiC, resulting in greater roughness, while lower energy concentrates on m fibers, yielding higher vaporization rates. C fiber orientation significantly impacts removal rates: processing time is shortest at θ = 90°, longest at θ = 0°, and increases as θ decreases. Typical defects such as delamination were observed between alternating 0° and 90° fiber bundles or at hole entrances. Cracks were also detected at the SiC matrix–C fiber interface. The proposed hole-enlargement process enhances chip removal efficiency through its helical structure and internal flushing, reduces abnormal discharges, mitigates micro hole taper, and thereby improves forming quality. This study provides practical references for the EDM of C/SiC composite material. Full article