Advanced Materials Technologies最新文献

MicroRNAs (miRNAs) are pivotal elements to regulate gene expressions, which are thus involved in the progression of a wide range of diseases. In this study, an electrochemical approach is established to detect miR-122 level, which can potentially assist in the diagnosis of non-alcoholic fatty liver disease. A 3D DNA scaffold is first constructed on the surface of the working electrode to improve the reactivity and accessibility. After miR-122 induced intramolecular strand displacement polymerization, the DNA layer is blocked and fails to localize signal strands. The varied electrochemical response is amplified by target recycles due to the quick intramolecular process. This method is highly sensitive and specific. It also effectively differentiates miRNA expression profiles across different clinical samples. The modular design of the DNA probes allows convenient adaptation to other targets, making it a useful tool for miRNA-related studies and clinical applications.

Cadmium selenide (CdSe), with a 1.7 eV bandgap, is a promising high-bandgap semiconductor for tandem solar cells, yet device efficiencies are hindered by rapid minority carrier recombination. Here, polycrystalline CdSe solar cells are investigated using radiative emission spectroscopy, time-resolved photoluminescence, and density functional theory, revealing fast (sub-nanosecond) minority carrier trapping by selenium vacancy-related defect states with densities of (5–50) × 10¹⁷ cm⁻³, limiting carrier mobility and increasing recombination. By reducing absorber thickness to ≈0.5 µm, trapping effects are mitigated, achieving a record open-circuit voltage of 917 mV, a 165 mV improvement over prior reports. These findings clarify the role of Se vacancies in limiting CdSe solar cell performance and provide insights applicable to CdSe and CdSeTe thin-film photovoltaics. This work advances understanding of defect-mediated losses in II–VI semiconductors and suggests pathways for improving solar cell performance through defect control.

Precise flow rate control is critical for microfluidic systems in biomedical, chemical, and analytical applications. Conventional flow-regulating microvalves often depend on complex, active components for sensor-based feedback. Active flow rate control increases system complexity and cost. For applications that require a constant flow rate, independent of the inlet pressure, a passive controller is a more favorable option. This paper presents a passive micro elastofluidic device that achieves autonomous flow control through elastic membrane deformation, eliminating the need for external actuation and power supply. The device incorporates a single elastic polydimethylsiloxane (PDMS) membrane integrated into a compact, multi-layer polymethyl methacrylate (PMMA) device. Utilizing both fluid-structure interaction (FSI) simulation in COMSOL and experimental validation, the influence of membrane shape (rectangular, circular, elliptical) and thickness (300–350 µm) on flow regulation is investigated. The results demonstrate that circular membranes offer the most stable flow control with minimum variation (2.63%), while thicker membranes improve regulation precision but raise threshold pressures. Experimental results closely matched simulation predictions, confirming the robust self-regulating behavior of the device. This work offers a simple, cost-effective solution for consistent passive flow control in microfluidic platforms, with applications in precise drug delivery, chemical synthesis, and lab on a chip.

The growing demands of advanced display technology and high-density electronic devices necessitate materials for next-generation flexible electronics that combine mechanical deformation durability with superior electromagnetic interference shielding effectiveness (EMI SE) and thermal dissipation capabilities. However, the fabrication of such sheets that satisfy all these requirements presents several technological challenges. This study proposes a highly flexible, multilayered hybrid sheet designed to meet these requirements, employing graphite foil, known for its excellent electrical and high thermal conductivity, as a core layer, with conductive polydimethylsiloxane (PDMS)/copper (Cu)/silicon carbide (SiC) composites on both sides. The optimized hybrid sheet yields a maximum EMI SE of 56.14 dB, a vertical thermal conductivity of 1.10 W mk⁻¹, and a horizontal thermal conductivity of 30.45 W mk⁻¹, representing improvements of 381%, 80%, and 3659%, respectively, over a reference hybrid sheet. Furthermore, the hybrid sheet exhibits excellent flexibility, with no cracks after over 500 000 cycles in a 1.5R repeated folding test. These results validate the developed hybrid sheet's potential as a multifunctional solution for EMI shielding and thermal management in next-generation flexible electronic devices.

This study reports the fabrication and characterization of bipolar, fully printed organic thermoelectric generators on flexible substrates. All fabrication and testing are carried out under ambient conditions, demonstrating the feasibility of low-cost, scalable manufacturing. The thermoelectric performance is evaluated in both flat and bent configurations, revealing a clear enhancement under mechanical deformation. The Seebeck coefficient of a single thermocouple increases from 30 µV K⁻¹ in the flat state to 38.9 µV K⁻¹ when bent, while the maximum output power rises from 8.8 to 14.9 nW. The devices also exhibit good stability, retaining ≈90% of their output power after 60 days of ambient exposure. These results confirm that fully printed, flexible organic thermoelectric generators are robust and lightweight energy harvesters whose performance improves under mechanical stress, highlighting their potential for real-world, mechanically dynamic applications.

Oxygen-depleted YBa₂Cu₃O_7−δ exhibits a substantial drop in the normal-state resistivity and an increase in the superconducting critical temperature when illuminated with visible light. The photo-induced states are metastable, slowly decaying at high temperatures and essentially persistent at low temperatures. In this work, this effect is exploited to modify the response of half-wavelength YBa₂Cu₃O_7−δ resonators and simultaneously the high-sensitivity of the resonant circuit is used to investigate the persistent photodoping of this material. Under illumination, the bolometric effect and photodoping are clearly distinguished by the different time scales associated with each mechanism. Using a 60 µm-wide laser spot, the properties of the resonator are locally and reversibly modified, and the position-dependent sensitivity of the device is demonstrated. This enables the direct imaging of standing waves at both the fundamental resonance and the second harmonic.

The emergence of additive manufacturing has promoted the preparation of complex porous implants, endowed medical porous implants with better mechanical properties, reduced stress shielding effect, and facilitated the integration of implants with bone tissues. However, the functionalization of medical porous implants still needs to be strengthened. Surface modification can alter surface morphology or load form composition of the material, endow the material with good biological functions such as osteogenesis and antibacterial, and mechanical properties, which is of great significance to improving the safety and effectiveness of the material. Unlike bulk materials, porous implants have complex internal structures, and their modification is mostly performed in fluid (liquid, gas) media to achieve good internal structure encapsulation. This article briefly introduces additive manufacturing technologies of different types of materials, analyzes the characteristics of different molding processes and the existing surface problems, classifies the modification methods according to surface modification principle and the nature of the components, and summarizes the advantages and disadvantages of different modification methods and influencing factors, with aim to provide new ideas for the surface modification of additively manufactured medical porous implants.

Direction-dependent control of propagating electromagnetic radiation plays a crucial role in emerging photonic technologies, including isolators, circulators, detectors, and sensors. Typically, the directional control is achieved through nonreciprocal mechanisms involving magnetic biasing, spatiotemporal modulation, or nonlinear effects. However, incorporation of these techniques into the terahertz (THz) regime is cumbersome due to the material limitations and integration complexity. In this context, a planar metasurface design composed of geometrically asymmetric split ring resonators (SRRs) is presented, enabling unidirectional reflection. The asymmetry is induced by laterally displacing the capacitive gap in SRRs. The geometrical asymmetry in SRR induces asymmetric radiative loss, resulting in strong reflection from one direction and near-complete suppression from the opposite. This thorough investigations demonstrate a reduction in resonance intensity (and resonance Q-factor) with increasing geometric asymmetry, indicating redistribution of energy stemming from radiative loss engineering. The demonstrated metasurface designs enable controlled unidirectional reflection by accessing dark modes through introducing asymmetry in well accepted SRR-based planar metasurface configuration.

Smart textiles require conductive polymer filaments that balance electrical performance with industrial processability. This study presents a hybrid nanofiller approach combining branched carbon nanotubes (bCNTs) and carbon black (CB) in polyamide 6 (PA6), enabling scalable melt spinning of high-performance conductive filaments. Comparative analysis of PA6/bCNT, PA6/CB, and PA6/bCNT/CB systems established structure–property–processing relationships essential for smart textile applications. Rheological characterization reveals that the hybrid system merges the strong conductive network of bCNTs with the improved spinnability provided by CB, ensuring industrial-scale processability. The optimized PA6/3 wt.% bCNT/3 wt.% CB composite achieved low resistivity (≈50 Ω·cm) while maintaining stable spinning at winding speeds up to 1000 m min⁻¹. A structural evolution model is proposed, showing how CB particles act as bridging agents between aligned bCNTs, stabilizing conductive pathways under high draw ratios. Complementary microscopy, thermal, and mechanical analyses validated this mechanism and confirmed the balance of conductivity, thermal stability, and mechanical performance. By integrating material design, process optimization, and functional validation, this work overcomes key barriers limiting commercial conductive filaments. The developed hybrid technology offers cost-effective, scalable solutions for next-generation smart textiles in wearable electronics, strain sensing, and electromagnetic shielding.

Mechanical metamaterials (MMs) exhibit unique properties through rational design, thereby attracting significant research interest. However, most studies focus on their intrinsic mechanical characteristics, with limited exploration of multifunctional and system-level applications beyond mechanics. This limitation primarily arises from the fabrication of MMs heavily dependent on continuous additive manufacturing, which results in fixed mechanical properties, restricted scale, and degraded structural efficiency, hindering adaptation to multifunctional system demands. To address these aspects, a hierarchical discrete assembly strategy is developed to achieve a synergy of scalability, ultrahigh structural efficiency, and system-level functionality. Upon this strategy, a class of discretely assembled lattice metamaterials (DALMs) with different macroscopic dimensions (>1 m) is fabricated using L-shaped components. Then, compressive responses and failure mechanisms of the DALMs are investigated through experiments and finite element simulations. The DALMs demonstrate an ultralow density of 11 kg m⁻³, with specific stiffness and specific strength reaching 119 and 3 kPa m³ kg⁻¹, outperforming existing modular MMs by 32% and 98%, respectively. Finally, a modular unmanned aerial system (MUAS) is developed by integrating a DALM-based fuselage with functional modules. Compared with similars systems, the MUAS achieves a 85% increase in payload capacity to 1.5 kg, and a 42% increase in thrust-to-weight ratio to 1.76.