Small Methods最新文献

Genetically encoded voltage indicators (GEVIs) have significantly advanced voltage imaging, offering spatial details at cellular and subcellular levels not easily accessible with electrophysiology. In addition to fluorescence imaging, certain chemical bond vibrations are sensitive to membrane potential changes, presenting an alternative imaging strategy; however, challenges in signal sensitivity and membrane specificity highlight the need to develop vibrational spectroscopic GEVIs (vGEVIs) in mammalian cells. To address this need, a vGEVI screening approach is developed that employs hyperspectral stimulated Raman scattering (hSRS) imaging synchronized with an induced transmembrane voltage (ITV) stimulation, revealing unique spectroscopic signatures of sensors expressed on membranes. Specifically, by screening various rhodopsin-based voltage sensors in live mammalian cells, a characteristic peak associated with retinal bound to the sensor is identified in one of the GEVIs, Archon, which exhibited a 70 cm^-1 red shift relative to the membrane-bound retinal. Notably, this peak is responsive to changes in membrane potential. Overall, hSRS-ITV presents a promising platform for screening vGEVIs, paving the way for advancements in vibrational spectroscopic voltage imaging.

The electrocaloric effect refers to the temperature change in a material when an electric field is applied or removed. Significant breakthroughs revealed its potential for solid-state cooling technologies in past decades. These devices offer a sustainable alternative to traditional vapor compression refrigeration, with advantages such as compactness, silent operation, and the absence of moving parts or refrigerants. Electrocaloric effects are typically studied using indirect methods based on polarization data, which suffer from inaccuracies related to assumptions about heat capacity. Direct methods, although more precise, require device fabrication and face challenges in studying meso- or nanoscale systems, like 2D materials, and materials with non-uniform polarization textures where high spatial resolution is required. In this study, a novel technique, Scanning Electrocaloric Thermometry, is introduced for characterizing the local electrocaloric effect in nanomaterials. This approach achieves high spatial resolution by locally applying electric fields and by simultaneously measuring the resulting temperature change. By employing AC excitation, the measurement sensitivity is further enhanced and the electrocaloric effect is disentangled from other heating mechanisms such as Joule heating and dielectric losses. The effectiveness of the method is demonstrated by examining electrocaloric and heat dissipation phenomena in 2D In₂Se₃ micrometer-sized flakes poly(vinylidene fluoride-trifluoroethylene) films.

Separating n-butane/iso-butane is a challenging and energy-intensive task in the petrochemical industry. There have been only several adsorbents reported for C4 paraffins separation while they are confronted in real-world applications with either poor selectivity or low n-butane uptake capacity. In this study, a fluorinated zinc-based metal-organic framework (MOF), Znpyc-CF₃, derived from Znpyc-CH₃ is developed, which has fluorine-containing functional groups on the pore surface that can enhance the interaction with the linear n-butane. Remarkably, this fluorinated porous material demonstrates both high n-butane uptake (55.5 cm³ g⁻¹) and excellent selectivity (IAST selectivity = 187) at ambient temperature. Multicycle breakthrough experiments confirmed its practical performance for real gas mixtures. Znpyc-CF₃ exhibits outstanding stability, maintaining its structural integrity after repeated sorption cycles and dynamic breakthrough tests under both dry and highly humid conditions. The preferential adsorption mechanism of n-butane is further elucidated through Grand Canonical Monte Carlo (GCMC) simulations and Density Functional Theory (DFT) calculations. Overall, this research presents an efficient and stable adsorbent for the separation of butane isomers.

Metal halide scintillators for X-ray imaging have shown remarkable potential, however, achieving large-area film has been hindered by challenges in materials design and fabrication methods, particularly regarding composition uniformity for high-resolution imaging applications. Here, a multi-source vapor deposition (MSVD) method is employed to realize the facile composition modulation by designing MA⁺ and Br^- (MA⁺ = methylammonium) co-doped Cs₂ZrCl₆ (MCZCB) and further synthesizing a uniform and large-area scintillator film. The incorporation of MA⁺ and Br^- ions, with their slightly larger ionic radius, induces lattice distortion, enhancing the self-trapped excitons (STEs) luminescence of the MCZCB and significantly boosting the photoluminescence quantum yield (PLQY) from 70% in pristine Cs₂ZrCl₆ (CZC) to an impressive 95%. Finally, a large-area of 100 cm² and 95% visible light transparent scintillator film is fabricated, achieving a spatial resolution of 25.1 lp mm^-1. This result demonstrates that MSVD technology is promising as a practical strategy for fabricating large-area X-ray imaging film.

This study presents the development of electrostatic dual-carbon-fiber (CF) microgrippers for the precise manipulation of single SiO₂ microparticles (diameters >3 µm) at low operating voltages of 5 to 15 V. Theoretical calculations and finite element analysis (FEA) simulations demonstrate that the microgrippers utilize a non-uniform electric field generated by dual CF electrodes to create a dielectrophoresis force for the pick-and-place manipulation of microparticle. After the removal of dielectrophoresis force by turning off the voltage, particle release is facilitated by van der Waals forces from the substrate surface. This approach eliminates the need for additional corona discharge fields or vibrational separators for particle release, ensuring accurate 2D patterning and 3D stacking of SiO₂ microparticles. The microgrippers show significant potential for applications in the individual separation and assembly of microparticles, such as lunar soil and interstellar dust, as well as single-cell extraction and positioning. Additionally, the developed microgrippers offer broad utility in micro/nano-manufacturing, micro/nano-electronic circuits, physics, chemistry, and biomedicine.

As silicon-based transistors approach their physical limits, the challenge of further increasing chip integration intensifies. 2D semiconductors, with their atomically thin thickness, ultraflat surfaces, and van der Waals (vdW) integration capability, are seen as a key candidate for sub-1 nm nodes in the post-Moore era. However, the low dielectric integration quality, including discontinuity and substantial leakage currents due to the lack of nucleation sites during deposition, interfacial states causing serious charge scattering, uncontrolled threshold shifts, and bad uniformity from dielectric doping and damage, have become critical barriers to their real applications. This review focuses on this challenge and the possible solutions. The functions of dielectric materials in transistors and their criteria for 2D devices are first elucidated. The methods for high-quality dielectric integration with 2D channels, such as surface pretreatment, using 2D materials with native oxides, buffer layer insertion, vdW dielectric transfer, and new dielectric materials, are then reviewed. Additionally, the dielectric integration for advanced 3D integration of 2D materials is also discussed. Finally, this paper is concluded with a comparative summary and outlook, highlighting the importance of interfacial state control, dielectric integration for 2D p-type channels, and compatibility with silicon processes.

Blade-coating has emerges as a critical route for scalable manufacturing of perovskite solar cells. However, the N₂ knife-assisted blade-coating process under ambient conditions typically yields inferior-quality perovskite films due to inadequate nucleation control and disorderly rapid crystallization. To address this challenge, a novel solvent engineering strategy is developed through the substitution of N-methyl-2-pyrrolidone (NMP) with 1,3-dimethyl-1,3-diazinan-2-one (DMPU). The unique physicochemical properties of DMPU, characterized by low vapor pressure, strong coordination capability, and limited PbI₂ solubility, synergistically regulate nucleation and crystallization kinetics. This enables rapid nucleation, stabilization of intermediate phases in wet films, and controlled crystal growth, ultimately producing phase-pure perovskite films with reduced defect density. Moreover, the feasibility and superiority of the mixed solvent strategy are demonstrated. The optimized blade-coated PSCs achieve a power conversion efficiency of 21.74% with enhanced operational stability, retaining 84% initial efficiency under continuous 1-sun illumination for 1,000 h. This work provides new insights into solvent design for preparing blade-coated perovskite films.

Monitoring the morphology and dynamics of both individual and collective cells is crucial for understanding the complexities of biological systems, investigating disease mechanisms, and advancing therapeutic strategies. However, traditional live-cell workstations that rely on microscopy often face inherent trade-offs between field of view (FOV) and resolution, making it difficult to achieve both high-throughput and high-resolution monitoring simultaneously. While existing lens-free imaging technologies enable high-throughput cell monitoring, they are often hindered by algorithmic complexity, long processing times that prevent real-time imaging, or insufficient resolution due to large sensor pixel sizes. To overcome these limitations, here an imaging platform is presented that integrates a custom-developed 500 nm pixel-size, 400-megapixel sensor with lens-free shadow imaging technology. This platform is capable of achieving imaging at a speed of up to 40s per frame, with a large FOV of 1 cm² and an imaging signal-to-noise ratio (SNR) of 42 dB, enabling continuous tracking of individual and cell populations throughout their entire lifecycle. By leveraging deep learning algorithms, the system accurately analyzes cell movement trajectories, while the integration of a K-means unsupervised clustering algorithm ensures precise evaluation of cellular activity. This platform provides an effective solution for high-throughput live-cell morphology monitoring and dynamic analysis.

Electromagnetic interference (EMI) significantly affects the performance and reliability of electronic devices. Although current metallic shielding materials are effective, they have drawbacks such as high density, limited flexibility, and poor corrosion resistance that limit their wider application in modern electronics. This study investigates the EMI shielding properties of 3D-printed conductive structures made from polylactic acid (PLA) infused with 0D carbon black (CB) and 1D carbon nanotube (CNT) fillers. This study demonstrates that CNT/PLA composites exhibit superior EMI shielding effectiveness (SE), achieving 43 dB at 10 GHz, compared to 22 dB for CB/PLA structures. Further, conductive coating of polyaniline (PANI) electrodeposition onto the CNT/PLA structures improves the SE to 54.5 dB at 10 GHz. This strategy allows fine control of PANI loading and relevant tuning of SE. Additionally, the 3D-printed PLA-based composites offer several advantages, including lightweight construction and enhanced corrosion resistance, positioning them as a sustainable alternative to traditional metal-based EMI shielding materials. These findings indicate that the SE of 3D-printed materials can be substantially improved through low-cost and straightforward PANI electrodeposition, enabling the production of customized EMI shielding materials with enhanced performance. This novel fabrication method offers promising potential for developing advanced shielding solutions in electronic devices.

The advancement of zinc-ion batteries (ZIBs) is propelled by their inherent safety, cost-effectiveness, and environmental sustainability. This study investigates the role of sulfolane (SL), a polar aprotic solvent with a high dielectric constant, as an electrolyte additive to enhance ion transport and electrochemical performance in V₂C MXene cathodes for high-performance ZIBs. The addition of 1% SL optimizes Zn-ion transport by increasing ionic conductivity, suppressing electrolyte decomposition, and mitigating zinc dendrite formation. Galvanostatic Intermittent Titration Technique (GITT) analysis reveals a reduction in Zn²⁺ diffusion coefficient from 1.54 × 10⁻⁷ cm²/s in 2 m ZnSO₄ to 1.07 × 10⁻⁹ cm² s^-1 in the SL-modified system, indicating a more confined Zn²⁺ transport environment. Electrochemical Impedance Spectroscopy (EIS) further demonstrates a substantial decrease in activation energy from 123.78 to 65.08 kJ mol⁻¹, signifying improved charge transfer kinetics. Ex situ XRD confirms that SL stabilizes the phase transformation of V₂C to Zn₀.₂₉V₂O₅, enhancing structural integrity. The modified system achieves an impressive specific capacity of 545 mAh g⁻¹ at 0.5 A g⁻¹ and exhibits exceptional cycling stability, retaining 91% capacity over 7000 cycles at 20 A g⁻¹. These findings underscore the potential of sulfolane as a key additive for advancing V₂C MXene-based ZIBs.