Nanoscale Structures Research Articles

Fabrication of an Artificial Pulley Based on Electrospun Composite Polyurethane/Polycaprolactone Nanofibers for Hand Surgery: Structural, Mechanical, In Vitro, and In Vivo Examinations.

Injuries to the hand's flexor pulley system can be debilitating, causing pain and restricting movement of the affected finger(s). The creation of a biocompatible artificial pulley could potentially alleviate some of the complications associated with current surgical treatments. In this study, a biocompatible artificial pulley was fabricated by using polycaprolactone (PCL) and polyurethane (PU) in the form of an electrospun nanofiber structure. All scaffolds were structurally analyzed using FESEM imaging, porosity, FTIR, and DSC examinations. Mechanical properties were evaluated, and in vitro studies were conducted on the degradation rate, swelling ratio, and toxicity. Immune response to fabricated scaffolds was evaluated by implanting them under the skin of rats for further pathological examination. All scaffolds exhibited a nanoscale structure and high porosity without any undesirable functional groups. The 25% PCL scaffold showed 17%, 20%, 80%, 17%, and 70% significant increases in Fmax, final stress, final strain, Young's modulus, and elongation percentage, respectively. In fact, the PCL25% scaffold demonstrated more than 100% improvement in mechanical properties compared to those of A2 and A4 natural pulleys. Additionally, all scaffold structures showed cell viability similar to that of the control sample. The study suggests that scaffolds made of 25% PCL hold promise as effective artificial pulleys for reconstructing the flexor tendon pulley system in cases of injury.

Using 4D-STEM to measure the nanoscale structure of materials in two and three dimensions

Using 4D-STEM to measure the nanoscale structure of materials in two and three dimensions

Measurements of secondary electron emission yield in the linear plasma simulator BPD-PSI

The secondary emission properties of the surface play one of the key roles in its interaction with plasma. This paper presents the first study of electron-induced electron emission yield performed in the linear plasma simulator BPD-PSI. To verify the applicability of the measurement technique used, a series of experiments was conducted to investigate the total secondary electron yield as a function of the energy of primary electrons for several pure elements, such as carbon, copper, and tungsten. Particular attention was paid to the latter as one of the essential plasma-facing materials, due to its ability to withstand moderate plasma loads. The change in the total secondary electron yield of tungsten was studied in-vacuo after each subsequent change in its surface morphology as a result of: annealing at 2770 K, exposure to pure helium plasma at 1250 K and annealing of plasma-modified tungsten surface at 2770 K. The growth of nanoscale structures, known as fuzz, on its surface caused a reduction in the total yield of secondary electrons by 10–18% compared to the clean surface. A non-monotonic relationship between total secondary electron yield and primary electron energy was observed. The interpretation of this phenomenon is given in the present work.

Cobalt-doped tungsten suboxides for supercapacitor applications

A crucial hurdle in developing supercapacitors is the creation of metal oxides with nanoscale structures that possess improved chemically active surfaces, ion/charge transport kinetics, and minimized ion-diffusion pathways. A metal-doping strategy to produce oxygen vacancies and increase electrical conductivity has proven effective for designing high-performance materials for energy storage devices. Herein, cobalt-doped tungsten suboxide (Co-doped W18O49) is grown on carbon cloth (CC) using a solvothermal approach and used as an electrode material for supercapacitor applications for the first time. Through this strategy, structurally distorted W18O49 is obtained by detecting a more apparent amorphous area caused by forming more oxygen vacancies with the bending of the lattice fringes. Benefiting from the synergy of more oxygen vacancies, increased lattice spacing, a high specific surface area, and accelerated ion diffusion, the Co-doped W18O49/CC electrode achieves a specific capacity of 475 C g−1 (792 F g−1) at a current density of 1.0 A g−1, which is superior to that of the undoped W18O49/CC (259 C g−1, 432 F g−1) and among the highest reported to date. Interestingly, the asymmetric supercapacitor device assembled using Co-doped W18O49/CC//AC/CC can provide a high energy density of 35.0 Wh kg−1. This strategy proves that the distortion of the W18O49 structure by Co doping improves the ion storage performance and self-discharge behavior. Also, it can enhance the energy storage performance of other electrode materials.

Eliciting impact of nano-clay reinforcement and processing schemes on polyurethane chain dynamics by gold sputtering patterns (GSPs)

This article narrates how processing “bias” affects polymer chain dynamics due to variable 2D-nanofiller interfaces. Importance of this biasing can be assessed by the significant improvement in thermal and mechanical properties we have recently published for polyurethane-2D clay nanocomposite coatings. We intricately look at the nanoscale structure and subsequent interface formation between 2D clay and PU chains to understand the changes in morphology. Polyurethane (PU) chain dynamics was observed through the gold (Au) sputtered patterns in field emission electron microscopy (FESEM) images. These were fitted with circles and our findings confirm the presence of an attractive interface between PU and 2D nanoclay. Circle fitting elicits important data like the critical area () and critical relative frequency () which are used to evaluate the polymer chain dynamics and morphology. We find that is related to circularity, and reinforcing nanoclay to the PU matrix enhances by 4.6% and 6.9% with simultaneous use of ultrasonic bath and high shear homogenizer. This is further correlated with the already established methods of small angle X-Ray scattering (SAXS) and Fourier transform infrared (FTIR) spectroscopy to generate a fresh perspective on interfacial interactions in PU-2D clay nanocomposites.

One-pot synthesis of nano Zr-based metal-organic frameworks for fluorescence determination of quercetin and Hg2+

In this study, a nanoscale Zr-based metal–organic framework (nano-Zr-MOF) was prepared by one-pot method using meso-tetra(4-carboxyphenyl)porphyrin as organic ligand and Zr4+ as metal unit. The nanoscale structure endows it with excellent dispersion in water. The nano-Zr-MOF exhibited intense red fluorescence, which could be significantly quenched by the addition of quercetin, probably due to its electron-rich framework. The high selectivity for quercetin detection was verified with analogues and common ions as interfering agents. Moreover, the nano-Zr-MOF could be used as a highly selective and sensitive sensor for the detection of Hg2+. The detection limits for quercetin and Hg2+ were 0.026 μM and 0.039 μM, respectively. This fluorometric method was successfully applied to detect quercetin in red wine and food samples with satisfactory recoveries ranging from 83.7–112.3% and 81.8–115.9%, respectively. The recovery in detection of Hg2+ in lake water were ranging from 97.1–109.2%.

Thermal Transport in Nanoelectronic Devices Cooled by On-Chip Magnetic Refrigeration.

On-chip demagnetization refrigeration has recently emerged as a powerful tool for reaching microkelvin electron temperatures in nanoscale structures. The relative importance of cooling on-chip and off-chip components and the thermal subsystem dynamics are yet to be analyzed. We study a Coulomb blockade thermometer with on-chip copper refrigerant both experimentally and numerically, showing that dynamics in this device are captured by a first-principles model. Our work shows how to simulate thermal dynamics in devices down to microkelvin temperatures, and outlines a recipe for a low-investment platform for quantum technologies and fundamental nanoscience in this novel temperature range.

Exploration of Organic Nanomaterials with Liquid-Phase Transmission Electron Microscopy.

ConspectusOrganic, soft materials with solution-phase nanoscale structures, such as emulsions, hydrogels, and thermally responsive materials, are inherently difficult to directly image via dry state and cryogenic-transmission electron microscopy (TEM). Therefore, we lack a routine microscopy method with sufficient resolution that can, in tandem with scattering techniques, probe the morphology and dynamics of these and many related systems. These challenges motivate liquid cell (LC) TEM method development, aimed at making the technique generally available and routine. To date, the field has been and continues to be dominantly focused on analyzing solution-phase inorganic materials. These mostly metallic nanoparticles have been studied at electron fluxes that can allow for high-resolution imaging, in the range of hundreds to thousands of e- Å-2 s-1. Despite excellent contrast, in these cases, one often contends with knock-on damage, direct radiolysis, and sensitization of the solvent by virtue of enhanced secondary electron production by the impinging electron beam. With an interest in soft materials, we face both related and distinct challenges, especially in achieving a high-enough contrast within solvated liquid cells. Additionally, we must be aware of artifacts associated with high-flux imaging conditions in terms of direct radiolysis of the solvent and the sensitive materials themselves. Regardless, with care, it has become possible to gain real insight into both static and dynamic organic nanomaterials in solution. This is due, in large part, to key advances that have been made, including improved sample preparation protocols, image capture technologies, and image analysis, which have allowed LCTEM to have utility. To enable solvated soft matter characterization by LCTEM, a generalizable multimodal workflow was developed by leveraging both experimental and theoretical precedents from across the LCTEM field and adjacent works concerned with solution radiolysis and nanoparticle tracking analyses. This workflow consists of (1) modeling electron beam-solvent interactions, (2) studying electron beam-sample interactions via LCTEM coupled with post-mortem analysis, (3) the construction of "damage plots" displaying sample integrity under varied imaging and sample conditions, (4) optimized LCTEM imaging, (5) image processing, and (6) correlative analysis via X-ray or light scattering. In this Account, we present this outlook and the challenges we continue to overcome in the direct imaging of dynamic solvated nanoscale soft materials.

Water repellence of biomimetic structures fabricated via femtosecond laser direct writing

Femtosecond laser direct writing based on two-photon polymerization (TPP), which is a sub-classification of vat photopolymerization, has the advantages of unlimited geometrical freedom and high resolution, and has attracted significant interests from scientists and engineers in recent years. In the present study, TPP fabrication was performed using a laser equipment with wavelength of 514 nm. The collimated beam diameter before the focusing lens was measured as 5 mm and the focused laser spot diameter was calculated as 280 nm. Key TPP processing parameters were investigated for the fabrication of nanowires, and micro/ nanoscale biomimetic structures, including cone and pinecone structures. The finest nanowire has a diameter of 105 nm and is achieved at the laser power of 0.8 μW (near the laser polymerization threshold). For the three-dimensional (3D) structures, laser power, layer thickness and hatch spacing would influence the fabrication accuracy. Generation of a stiff 3D cone structure would require a minimum laser power of 1.4 μW when the hatch spacing and layer thickness are 200 nm. The optimum processing parameters (laser power 2.2 μW, hatch space and layer thickness 100 nm) can generate structures with dimensions close to the design values. For pinecones with nano features, the scanning strategies play a significant role in the nano fabrication accuracy. A row of pinecones and cones were fabricated and tested for their water repellence performance. The relationship between the performance and the nano cone density was investigated. The pinecone structures exhibit superior performance to the ones with no nano-scale structures, indicating that improved hydrophobicity can be achieved by designing the micro/nano hierarchical structures. The increased number density of the nano cones in a micro/nano hierarchical structure was found to profoundly enhance the water repellence of the structures. The mechanisms were discussed with Wenzel and Cassie models.

High-k Solution-Processed Barium Titanate/Polysiloxane Nanocomposite for Low-Temperature Ferroelectric Thin-Film Transistors.

Ferroelectric nanoparticles have attracted much attention for numerous electronic applications owing to their nanoscale structure and size-dependent behavior. Barium titanate (BTO) nanoparticles with two different sizes (20 and 100 nm) were synthesized and mixed with a polysiloxane (PSX) polymer forming a nanocomposite solution for high-k nanodielectric films. Transition from the ferroelectric to paraelectric phase of BTO with different nanoparticle dimensions was evaluated through variable-temperature X-ray diffraction measurement accompanied by electrical analysis using capacitor structures. A symmetric single 200 peak was constantly detected at different measurement temperatures for the 20 nm BTO sample, marking a stable cubic crystal structure. 100 nm BTO on the other hand shows splitting of 200/002 peaks correlating to a tetragonal crystal form which further merged, thus forming a single 200 peak at higher temperatures. Smaller BTO dimension exhibits clockwise hysteresis in capacitance-voltage measurement and correlates to a cubic crystal structure which possesses paraelectric properties. Bigger BTO dimension in contrast, demonstrates counterclockwise hysteresis owing to their tetragonal crystal form. Through further Rietveld refinement analysis, we found that the tetragonality (c/a) of 100 nm BTO decreases at a higher temperature which narrows the hysteresis window. A wider hysteresis window was observed when utilizing 100 nm BTO compared to 20 nm BTO even at a lower loading ratio. The present findings imply different hysteresis mechanisms for BTO nanoparticles with varying dimensions which is crucial in understanding the role of how the BTO size tunes the crystal structures for integration in thin-film transistor devices.

In-situ grown a zeolitic imidazolate framework for boosting sensitivity of breathable wearable electronics

Wearable electronics have emerged as versatile platforms for various biomedical applications. However, developing sensors that are both air-permeable and highly sensitive for long-term, subtle physiological signal monitoring remains a challenge. To overcome this, an innovative in-situ growth method was employed to decorate electrospun polyvinylidene fluoride (PVDF) nanofibers with a zeolitic imidazolate framework (known as ZIF-8). This approach has led to a remarkable 300% increase in sensitivity (5.94 kPa−1) compared to sensors prepared using pure PVDF nanofiber (1.42 kPa−1). This in-situ growth method effectively prevented ZIF-8 agglomeration, contributing to the desired improvement in permittivity (∼1.6), unlike blended ZIF-8/PVDF nanofiber. Furthermore, atomic force microscope and simulations were utilized to demonstrated that the nano-scale structures formed by the uniform growth of ZIF-8 significantly contribute to the enhanced sensitivity of the sensor. In addition to satisfactory air-permeability (10 mm/s) and high sensitivity, the as-prepared sensor exhibits excellent flexibility, enabling it to conform to irregular organ surfaces for real-time monitoring of pulse, respiration, and swallowing. This approach holds great promise for the development of highly sensitive and skin-friendly wearable electronics, offering significant benefits for healthcare advancement.

Vibration and Buckling Analysis of Nano-Scale Beams via Nonlocal Elasticity and Timoshenko Beam Theory : A Differential Quadrature Approach

A single-elastic beam model is being developed based on Eringens nonlocal elasticity and Timoshenko beam theory. Nonlocal parameter takes into account the small scale effects in the analysis of nano-size structures. Derived herein is a decoupled sixth-order nonlocal governing differential equations for the frequency and stability analysis of nano-scale short beams. The effect of shear deformation is thereby included in the small scale analysis. A Differential Quadrature (DQ) approach is being applied and its elaborate method of solution is illustrated. The higher order DQ approach is found to be a good numerical technique for the convenient and rapid solution of the aforementioned nonlocal problems. Frequency and buckling results for various scale-based nonlocal parameters are shown. Effect of number of interpolation points on the accuracy of the results is also investigated. It is seen that there is a significant effect of aspect ratio and nonlocal parameter on the nonlocal frequency and buckling loads of nano-scale beams. Also, the present study could open up a new approach of solution technique for the analysis of nano-scale structures based on nonlocal Timoshenko theory.

Metal-organic Zn-zoledronic acid and 1-hydroxyethylidene-1,1-diphosphonic acid nanostick-mediated zinc phosphate hybrid coating on biodegradable Zn for osteoporotic fracture healing implants.

Zn and its alloys are increasingly under consideration for biodegradable bone fracture fixation implants owing to their attractive biodegradability and mechanical properties. However, their clinical application is a challenge for osteoporotic bone fracture healing, due to their uneven degradation mode, burst release of zinc ions, and insufficient osteo-promotion and osteo-resorption regulating properties. In this study, a type of Zn2+ coordinated zoledronic acid (ZA) and 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) metal-organic hybrid nanostick was synthesized, which was further mixed into zinc phosphate (ZnP) solution to mediate the deposition and growth of ZnP to form a well-integrated micro-patterned metal-organic/inorganic hybrid coating on Zn. The coating protected noticeably the Zn substrate from corrosion, in particular reducing its localized occurrence as well as suppressing its Zn2+ release. Moreover, the modified Zn was osteo-compatible and osteo-promotive and, more important, performed osteogenesis in vitro and in vivo of well-balanced pro-osteoblast and anti-osteoclast responses. Such favorable functionalities are related to the nature of its bioactive components, especially the bio-functional ZA and the Zn ions it contains, as well as its unique micro- and nano-scale structure. This strategy provides not only a new avenue for surface modification of biodegradable metals but also sheds light on advanced biomaterials for osteoporotic fracture and other applications. STATEMENT OF SIGNIFICANCE: Developing appropriate biodegradable metallic materials is of clinical relevance for osteoporosis fracture healing, whereas current strategies are short of good balance between the bone formation and resorption. Here, we designed a micropatterned metal-organic nanostickmediated zinc phosphate hybrid coating modified Zn biodegradable metal to fulfill such a balanced osteogenicity. The in vitro assays verified the coated Zn demonstrated outstanding pro-osteoblasts and anti-osteoclasts properties and the coated intramedullary nail promoted fracture healing well in an osteoporotic femur fracture rat model. Our strategy may offer not only a new avenue for surface modification of biodegradable metals but also shed light on better understanding of new advanced biomaterials for orthopedic application among others.

Doped Graphene Quantum Dots as Biocompatible Radical Scavenging Agents.

Oxidative stress is proven to be a leading factor in a multitude of adverse conditions, from Alzheimer's disease to cancer. Thus, developing effective radical scavenging agents to eliminate reactive oxygen species (ROS) driving many oxidative processes has become critical. In addition to conventional antioxidants, nanoscale structures and metal-organic complexes have recently shown promising potential for radical scavenging. To design an optimal nanoscale ROS scavenging agent, we have synthesized ten types of biocompatible graphene quantum dots (GQDs) augmented with various metal dopants. The radical scavenging abilities of these novel metal-doped GQD structures were, for the first time, assessed via the DPPH, KMnO4, and RHB (Rhodamine B protectant) assays. While all metal-doped GQDs consistently demonstrate antioxidant properties higher than the undoped cores, aluminum-doped GQDs exhibit 60-95% radical scavenging ability of ascorbic acid positive control. Tm-doped GQDs match the radical scavenging properties of ascorbic acid in the KMnO4 assay. All doped GQD structures possess fluorescence imaging capabilities that enable their tracking in vitro, ensuring their successful cellular internalization. Given such multifunctionality, biocompatible doped GQD antioxidants can become prospective candidates for multimodal therapeutics, including the reduction of ROS with concomitant imaging and therapeutic delivery to cancer tumors.

Sirolimus-loaded exosomes as a promising vascular delivery system for the prevention of post-angioplasty restenosis.

Restenosis remains the main reason for treatment failure of arterial disease. Sirolimus (SIR) as a potent anti-proliferative agent is believed to prevent the phenomenon. The application of exosomes provides an extended-release delivery platform for SIR intramural administration. Herein, SIR was loaded into fibroblast-derived exosomes isolated by ultracentrifugation. Different parameters affecting drug loading were optimized, and exosome samples were characterized regarding physicochemical, pharmaceutical, and biological properties. Cytotoxicity, scratch wound assays, and quantitative real-time PCR for inflammation- and migration-associated genes were performed. Restenosis was induced by carotid injury in a rat carotid model and then exosomes were locally administered. After 14days, animals were investigated by computed tomography (CT) angiography, morphometric, and immunohistochemical analyses. Western blotting confirmed the presence of specific protein markers in exosomes. Characterization of empty and SIR-loaded exosomes verified round and nanoscale structure of vesicles. Among prepared formulations, desired entrapment efficiency (EE) of 76% was achieved by protein:drug proportion of 2:1 and simple incubation for 30min at 37°C. Also, the optimal formulation released about 30% of the drug content during the first 24h, followed by a prolonged release for several days. In vitro studies revealed the uptake and functional efficacy of the optimized formulation. In vivo studies revealed that %restenosis was in the following order: saline > empty exosomes > SIR-loaded exosomes. Furthermore, Ki67, alphasmooth muscle actin (α-SMA), and matrix metalloproteinase (MMP) markers were less expressed in the SIR-exosomes-treated arteries. These findings confirmed that exosomal SIR could be a hopeful strategy for the prevention of restenosis.

Towards scanning nanostructure X-ray microscopy.

This article demonstrates spatial mapping of the local and nanoscale structure of thin film objects using spatially resolved pair distribution function (PDF) analysis of synchrotron X-ray diffraction data. This is exemplified in a lab-on-chip combinatorial array of sample spots containing catalytically interesting nanoparticles deposited from liquid precursors using an ink-jet liquid-handling system. A software implementation is presented of the whole protocol, including an approach for automated data acquisition and analysis using the atomic PDF method. The protocol software can handle semi-automated data reduction, normalization and modeling, with user-defined recipes generating a comprehensive collection of metadata and analysis results. By slicing the collection using included functions, it is possible to build images of different contrast features chosen by the user, giving insights into different aspects of the local structure.

Defect and Interface Engineered Tungsten Bronze Superstructure Anode toward Advanced Sodium Storage

AbstractDefect and interface engineering, which can facilitate exceptional electrochemical stability and activity, are some of the most important strategies in devising electrode materials. However, the complex nanoscale chemistry and structure characteristics make the origin of electrochemical mechanism extremely difficult to understand. To eliminate this issue, the delicately designed 1D tungsten bronze superstructure anode, guided by defect and interface engineering, is successfully prepared for sodium storage to gain insight into the endogenous structure‐property relationships. It can realize the intensely enhanced Na+‐storage performance with a safe operating potential of ≈0.5 V, a high specific capacity of 228 mAh g−1 at 0.1 C and superior rate performance, which is attributed to the rapid electron and ion transfer process induced by abundant heterointerfaces. More importantly, it can convey an ultra‐stable long‐term cycling performance, with the capacity retention close to 90% after 4500 cycles at 5 C and 10000 cycles at 10 C, which can be explained by the inherently zero‐strain characteristic of a novel vacancy‐ordered superstructure in tungsten bronze Ba3.4Nb10O28.4 (BNO). This study reveals the structural origins of defect and interface engineering responsible for electrochemical mechanism, providing critical insight into the design of superior electrode materials.

Unexpected super anti-compressive styrene-acrylonitrile copolymer/polyurea nanocomposite foam with excellent solvent resistance, re-processability and shape memory performance

High-performance, recycling and environmental protection are the goal of the development of polymer materials in the future. The introduction of crosslinking and composite are two main ways to improve the comprehensive properties of materials, however, which leads to the non-recyclability of materials or brings difficulties to the recovery process. Here, we report a polymer nanocomposite foam with superior compression properties to most existing commercial foams, just originating from common commercial styrene-acrylonitrile copolymer (SAN) and polyurea (PUA), and develop a green and energy-efficient method to fabricate high-performance rigid foam by reactive plasticizing and reaction induced phase-separation combining with supercritical CO2 (sc-CO2) foaming. Reaction induced phase-separation results in the in-situ formation of nanoscale structure in the cell walls of the resultant foams, in which the crosslinked PUA is the dispersed phase with the size of 10–40 nm in the matrix of SAN. Optimizing crosslinking network structure of PUA dramatically improve the comprehensive performance of SAN/PUA nanocomposite foams. The resultant SAN/PUA nanocomposite foam shows some performance characteristic of thermosetting polymers, such as excellent heat resistance and solvent resistance than the SAN matrix, meanwhile the performance characteristic of thermoplastic polymers, such as re-processability. More interestingly, the SAN/PUA nanocomposite foam presents excellent shape memory performance. With the above exceptional performances, this polymer nanocomposite foam will be a perfect substitute for the existing commercial rigid foams.

On The Multiscale Structure and Morphology of PVDF‐HFP@MOF Membranes in The Scope of Water Remediation Applications

AbstractPoly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) is a highly versatile polymer used for water remediation due to its chemical robustness and processability. By incorporating metal‐organic frameworks (MOFs) into PVDF‐HFP membranes, the material can gain metal‐adsorption properties. It is well known that the effectiveness of these composites removing heavy metals depends on the MOF's chemical encoding and the extent of encapsulation within the polymer. In this study, it is examined how the micro to nanoscale structure of PVDF‐HFP@MOF membranes influences their adsorption performance for CrVI. To this end, the micro‐ and nanostructure of PVDF‐HFP@MOF membranes are thoroughly studied by a set of complementary techniques. In particular, small‐angle X‐ray and neutron scattering allow to precisely describe the nanostructure of the polymer‐MOF complex systems, while scanning microscopy and mercury porosimetry give a clear insight into the macro and mesoporosity of the system. By correlating nanoscale structural features with the adsorption capacity of the MOF nanoparticles, different degrees of full encapsulation‐based on the PVDF‐HFP processing and structuration from the macro to nanometer scale are observed. Additionally, the in situ functionalization of MOF nanoparticles with cysteine is investigated to enhance their adsorption toward HgII. This functionalization enhanced the adsorption capacity of the MOFs from 8 to 30 mg·g−1.

Nano- to microscale structural and compositional heterogeneity of artificial pinning centers in pulsed-laser-deposited YBa2Cu3O7−y thin films

The structure, composition, and spatial distribution heterogeneity of artificial pinning centers affect the critical current density of REBa2Cu3O7−y (RE: rare earth) coated conductors. Nanoscale structures and compositions have been analyzed with transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). However, microscale heterogeneity has been difficult to characterize. Here, YBa2Cu3O7−y thin films doped with double-perovskite Ba2YbNbO6 were prepared via pulsed-laser deposition and characterized with TEM, STEM, and scanning electron microscopy (SEM). Cross-sectional and plan-view TEM/STEM imaging revealed hybrid pinning structures consisting of nanorods, nanoparticles, and planar defects that were formed spontaneously. Nanorods were imaged with high spatial resolution via field-emission SEM of thin-foil specimens. Focused-ion-beam (FIB) micro-sectioning enables SEM imaging of microscale heterogeneity in nanorod spatial distributions. By using TEM/STEM in conjunction with FIB-SEM, the coated conductor inhomogeneity was directly evaluated from the nano- to micrometer scales.