Traditional methods for dielectric characterization and concentration measurements are hindered by technical limitations, the requirement for sample pretreatment, and complex instrument operation. To address these issues, a sensor that combines coplanar waveguide (CPW) and split ring resonator (SRR) technology is proposed in this paper, with the resonance frequency of 1.87 GHz and a corresponding transmission coefficient of up to −1.6 dB. This sensor enables non-destructive, real-time, and convenient measurements without the need for sample pretreatment. Organic solvents, including n-hexane, carbon tetrachloride, and ethyl acetate are characterized based on CPW-SRR sensor. The resonance frequency shifts range from 1.4 to 12.2 MHz in the sensor when samples with relative permittivity ranging from 1.89 to 80.1 are measured. Additionally, for the volume fractions (0%–100%) of ethanol solution and methanol-ethanol mixed solution, the sensor produces transmission coefficient responses of −1.625 to −1.468 dB and −1.556 to −1.464 dB, respectively. The sensor offers advantages of low loss, compact size, and cost-effectiveness, making it a promising technical solution for applications in microwave sensors, chemistry analysis, and integrated circuits.

Cold welding of metals at the nanoscale has been demonstrated to play a significant role in bottom‐up manufacturing and self‐healing processes of nanostructures and nanodevices. However, the welding mechanism at the nanoscale is not well understood. In this study, a comprehensive demonstration of the cold welding process of gold nanorods with different modes is presented through in situ liquid cell transmission electron microscopy. The experimental results and molecular dynamics simulations reveal that the nanorods are welded through the facet‐dependent atomic surface diffusion and rearrangement along {100} facets. The density functional theory calculations indicate that the preferred coalescence of two {100} surfaces is thermodynamically favorable. Unlike the prevalent “oriented attachment” in the nanoparticle coalescence, the misalignment of nanorod orientations and local stresses can induce grain boundaries and stacking faults in the welded interface.

Branched nanostructures have attracted significant attention due to their potential applications across diverse fields. Precise control over branched morphology is essential for enhancing their functionality, yet it remains a considerable challenge. In this work, in-situ liquid-cell transmission electron microscopy (LCTEM) is employed to investigate the controllable growth of seaweed-like iron oxide branches in the presence of charged gold nanoparticles (Au NPs) within an organic solution. In contrast to the conventional tip-splitting behavior observed in the absence of Au NPs, the branches exhibit directional and accelerated growth toward the Au NPs without further splitting. Finite-element analysis reveals that the local electric field between the charged Au NPs and the branches promotes reactant aggregation at the branch tips, thereby driving their directional and accelerated growth. This study provides insights into the growth mechanisms of seaweed-like nanostructures and highlights the potential of local electric fields for morphological control of branched structures.

Particle coalescence is a fundamental pathway of nanoparticle growth, directly governing structural reconstruction, defect formation, and morphological evolution. However, the underlying driving forces behind imperfect oriented attachment, including what initiates the coalescence of misoriented crystals and determines the resulting structures remain unclear, particularly in liquid environments. This study combines in situ liquid‐phase transmission electron microscopy with molecular dynamics calculations to investigate the coalescence dynamics of misoriented gold nanoparticles. Our findings reveal that misoriented nanoparticles can coalesce into a single crystal via a kinetically driven jump‐to‐coalescence process triggered by instantaneous hydration layer collapse. This coalescence is accompanied by a significant potential energy reduction, and the released energy enhances atomic mobility, particularly in small nanoparticles, enabling rapid structural rearrangement into a single crystal. Moreover, the initial contact position relative to the twin boundary determines the atomic diffusion pathway during the coalescence process of twin nanoparticles, while the twin boundary exhibits high stability during the merging process. These findings clarify the regulatory role of the kinetic factor in nanoparticle coalescence behavior and offer guidance for controlling crystal structure and designing twinned nanostructures in the liquid phase synthesis.

The nucleation pathway of metal nanocrystals critically governs their final structure and properties, representing a fundamental challenge across materials science, chemistry, physics, and biology. However, specific nonclassical pathways and the role of kinetics in early-stage nucleation remain elusive. Here, we combine in situ liquid phase transmission electron microscopy (LPTEM) and theoretical calculations to investigate the nucleation of silver nanoparticles. Our observations reveal a nonclassical pathway involving spinodal decomposition and transient amorphous prenucleation clusters. Subsequently, we report the independent formation and kinetic competition between metastable hexagonal close-packed (hcp) and stable face-centered cubic (fcc) silver phases under identical conditions. These results provide a detailed insight into nonclassical nucleation pathways and elucidate how kinetic and thermodynamic factors influence initial nucleation pathway while thermodynamic stability dictates the final product, thereby offering guidance for the controllable synthesis of metal nanocrystals.