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6 papers

Flexible and efficient triboelectric nanogenerators based on PVDF and boron nitride composite yarns and mats.

Sukumaran S et al. · Jul 9, 2026

Flexible and scalable energy-harvesting materials are the driving force behind the emerging era of wearable and self-powered electronics that seamlessly integrate into modern life. Hence, triboelectric nanogenerators (TENGs) offer a versatile solution for integrating energy generation into smart textiles. Here, electrospun poly(vinylidene fluoride) (PVDF) mats and yarns incorporating boron nitride (BN) nanoparticles (1, 3, 5, and 10 wt%) were fabricated and characterized. The 5 wt% BN/PVDF composite exhibited the highest β-phase content and crystallinity, owing to the role of BN as an efficient nucleating agent that facilitates β-phase crystallization through strong interfacial interactions between the nanofiller and PVDF matrix. The triboelectric output was systematically compared across different structural configurations, including electrospun mats, yarns, and rolled-mat geometries. The BN/PVDF yarn-based TENG delivered the highest power density of 303 ± 0.30 mW m -2 , representing ∼113% enhancement over pristine PVDF yarn and superior to previously reported PVDF-based devices. Moreover, despite its smaller active area, the yarn device produced higher power density than the mat counterpart (297 ± 0.43 mW m -2 ). These findings demonstrate that BN incorporation and yarn-based architecture enhanced power generation, providing a scalable route toward high-performance, flexible nanogenerators for wearable and self-powered electronics.

Engineering

Global Renewable Energy Infrastructure Resilience Under Climate Risks.

Hong J et al. · Jul 1, 2026

Accelerating global climate risks increasingly threaten renewable energy infrastructure (REI). However, little evidence on heterogeneous impacts of climate risks on REI across countries, the moderating role of REI resilience, and post-disaster recovery patterns is available, despite their critical importance for guiding resilient energy transitions and informing disaster risk governance. To address these issues, we employed dynamic panel models in 215 countries and regions from 2004 to 2022. We find that (1) climate risk significantly damages global REI, with disaster frequency and institutional resilience having mitigation effects. (2) The damage follows an inverted U-shape with increasing disaster frequency and an "N" shape with increasing disaster duration. As renewable energy generation share increases, the damage intensifies and progresses through four increasingly severe stages. (3) Economic resilience exhibits a "Creative destruction" effect in developed nations and a "Build back better" recovery in poor countries. (4) Although social resilience worsens climate disaster damage globally, high disaster frequency and institutional resilience can facilitate a "Recovery to trend" in socially advanced nations. (5) REI in South America is the most affected, followed by Asia and Africa, whereas Europe is the least impacted. Wind energy is the most vulnerable, followed by bioenergy, solar, and hydropower.

Engineering

Enzyme-catalysed synthesis of pyridines from biomass-derived feedstocks.

Sodré V et al. · Jul 1, 2026

Pyridines are found in many pharmaceuticals and agrochemicals, but are synthesised from fossil fuel conversion. 2,4- and 2,5-pyridinedicarboxylic acids have been reported as products from bioconversion of renewable lignin feedstocks using engineered strains of Rhodococcus jostii RHA1 (Z. Mycroft et al. , Green Chem. , 2015, 17 , 4974-4979), but previously it has been uncertain whether the formation of the pyridine ring was assisted by enzyme catalysis. The 4,5-extradiol ring fission product of protocatechuic acid, 4-carboxy-2-hydroxymuconate 6-semialdehyde (CHMS) shows structural similarity to α-ketoglutaric acid, the substrate for reductive amination by glutamate dehydrogenase (GDH). Testing of five glutamate dehydrogenase (GDH) isozymes from R. jostii RHA1 revealed that GDH5 catalyses NADH-dependent reductive amination of CHMS, and its cyclisation to form a dihydropyridine product. The dihydropyridine can be oxidised to 2,4-pyridinedicarboxylic acid using recombinant P. fluorescens dye-decolorizing peroxidase DyP1B, providing a route to substituted pyridines from a renewable feedstock.

Engineering

Compact on-chip fluorescence microscope for dynamic imaging of cellular processes and biomimetic systems.

Khoubafarin S et al. · Jun 25, 2026

Real-time and High-throughput fluorescence imaging is essential for probing dynamic cellular behavior in biomimetic and tissue-on-chip systems. While fluorescence microscopy provides high sensitivity and subcellular resolution, the intrinsic heterogeneity of these engineered tissues requires imaging multiple regions to obtain representative biological information. Meeting this need typically demands mechanical scanning systems, which add both hardware and software complexity and substantially increase cost. Here, we developed a compact and low-cost on-chip fluorescence microscopy platform that integrates a two-dimensional microlens substrate directly onto a complementary metal-oxide-semiconductor sensor to achieve high resolution and signal-to-noise ratio (SNR). Excitation light is delivered laterally through a prism to induce total internal reflection, effectively rejecting background illumination and allowing only fluorescence emission to reach the detector. The system's optical geometry was optimized using analytical modeling and numerical simulations to maximize photon collection and SNR. Using this optimized system, we first demonstrated its capability at the cellular level by capturing drug-induced oxidative stress and rapid intracellular signaling dynamics in BT-20 breast cancer cells. Once we were successfully able to monitor these dynamic processes, we next applied the system to biomimetic models. In a microfluidic tumor-endothelial co-culture, we visualized the passage of small molecules, nanoparticles, and ions across the endothelial barrier under controlled flow conditions. Integration with microfluidic co-culture systems further demonstrated its ability to study complex interactions within tumor microenvironments. By combining simplicity, sensitivity, and compatibility with biomimetic platforms, this on-chip fluorescence microscope enables wide-field monitoring of cellular dynamics across large populations, allowing observation of cell-to-cell variability and supporting applications in drug screening, cellular signaling studies, and tissue-on-chip research.

Engineering

Thermally modulated resonant quantum transport in asymmetric nanoscale junctions for optimal bias and power generation analysis.

Aly AH. · Jun 25, 2026

A phenomenological effective transport model inspired by Landauer-type resonant transport concepts is presented to investigate thermally modulated transport behavior in an asymmetric nanoscale junction under combined electrical and thermal driving. The proposed framework incorporates resonance alignment, thermal resonance modulation, finite-bias activation, damping effects, and structural asymmetry within a computationally efficient formulation. The transport response is systematically analyzed as functions of bias voltage, asymmetry strength, temperature, and resonance energy. The results show that increasing structural asymmetry reduces the magnitudes of the heat-current proxy, charge-current magnitude, and electrical power magnitude due to weaker effective transport coupling. However, the optimal bias voltage associated with the maximum electrical power magnitude remains only weakly affected within the investigated parameter range because the asymmetry factor primarily scales the transport amplitude while weakly modifying the resonance-alignment condition. The simulations further demonstrate that the maximum electrical power magnitude increases with temperature, whereas the thermal sensitivity gradually decreases at elevated temperatures. In addition, the optimal operating bias increases with resonance energy according to the resonance-alignment condition included in the model. A two-dimensional operating map identifies a stable high-performance transport region near 4-4.5 mV. All numerical parameters used in the simulations are explicitly reported to support reproducibility. The proposed framework provides a simplified and physically interpretable platform for analyzing resonance-dominated transport trends in asymmetric nanoscale systems and may serve as a useful basis for future microscopic or experimentally calibrated studies.

Engineering

Multiphysics Modeling and Analysis for Dendrite Problems in Solid-State Lithium/Sodium Metal Batteries.

Yu B et al. · Jun 25, 2026

The commercialization of liquid lithium-ion batteries has revolutionized the consumer electronics industry. However, conventional lithium-ion batteries with graphite anodes and organic electrolytes are approaching their intrinsic performance limits and struggle to meet the growing demands for higher energy density, reliability, and safety in electric vehicles and large-scale energy storage. Solid-state batteries utilizing lithium or sodium metal anodes are considered promising next-generation energy storage solutions. Despite this potential, the formation of dendrites during charge-discharge cycling remains a critical challenge. Dendrite growth can initiate a destructive feedback loop of crack propagation and further dendrite intrusion, ultimately leading to battery failure and performance degradation. Previous studies have predominantly focused on single physical domains, such as electrochemical, stress, or thermal fields. However, such single-physics approach limits the understanding of dendrite evolution under realistic, coupled multiphysics conditions. This review first compares the morphological characteristics of dendrites in liquid and solid-state metal batteries. It then critically examines the key factors and predictive models of dendrite formation, initially from single-physics and subsequently from an integrated multiphysics perspective. Finally, strategies for mitigating dendrite growth via multiphysics field regulation are summarized. By establishing a comprehensive framework that integrates morphology evolution, multiphysics modeling, and suppression strategies, this work provides a foundational theoretical understanding for addressing dendrite formation in solid-state lithium and sodium metal batteries.

Engineering