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1. Dynamic drop penetration of vertically oriented fiber arrays

   https://doi.org/10.1063/5.0246986  

   Rible, Gene_Patrick S; Chakpuang, Visalsaya; Holihan, Aidan D; Sebek, Hannah P; Osman, Hannah H; Brown, Kyle R; Wang, Wei; Dickerson, Andrew K (February 2025, Physics of Fluids)

   This experimental work investigates the impact dynamics of drops on vertically oriented, three-dimensional-printed (3D-printed) fiber arrays with variations in packing density, fiber arrangement, and wettability. These fiber arrays are inspired by mammalian fur, and while not wholly representative of the entire morphological range of fur, they do reside within its spectrum. We define an aspect ratio, a modified fiber porosity relative to the drop size, that characterizes various impact regimes. Using energy conservation, we derive a model relating drop penetration depth in vertical fibers to the Weber number. In sparse fibers where the Ohnesorge number is less than 4×10−3, penetration depth scales linearly with the impact Weber number. In hydrophobic fibers, density reduces penetration depth when the contact angle is sufficiently high. Hydrophilic arrays have greater penetration than their hydrophobic counterparts due to capillarity, a result that contrasts the drop impact-initiated infiltration of horizontal fibers. Vertical capillary infiltration of the penetrated liquid is observed whenever the Bond number is less than 0.11. For hydrophilic fibers, we predict that higher density will promote drop penetration when the contact angle is sufficiently low. Complete infiltration by the drop is achieved at sufficient times regardless of drop impact velocity. 

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2. Vertically Oriented Graphene Nanosheets for Electrochemical Energy Storage

   https://doi.org/10.1002/celc.202001364  

   He, Pingge; Chen, Shaowei (January 2021, ChemElectroChem)

   Abstract Vertically oriented graphene (VG) nanosheets exhibit unique structural characteristics, such as large accessible surface area, rich edges, high electrical conductivity, open network channels, and agglomeration resistance, for electrochemical energy‐storage applications (e. g., supercapacitors, lithium‐ion batteries, etc.). In this Review article, we summarize recent progress in the design and engineering of VG‐based electrodes for high‐performance electrochemical energy technologies within the context of energy‐storage mechanisms and charge‐transfer kinetics, and include a perspective to highlight the challenges and promises in the exploitation of vertically oriented two‐dimensional carbon nanostructures for further enhancement of the performance of electrochemical energy‐storage devices. 

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3. Large‐Scale Plasmonic Hybrid Framework with Built‐In Nanohole Array as Multifunctional Optical Sensing Platforms

   https://doi.org/10.1002/smll.201906459  

   Wang, Xuejing; Ma, Xuedan; Shi, Enzheng; Lu, Ping; Dou, Letian; Zhang, Xinghang; Wang, Haiyan (February 2020, Small)

   Abstract Light coupling with patterned subwavelength hole arrays induces enhanced transmission supported by the strong surface plasmon mode. In this work, a nanostructured plasmonic framework with vertically built‐in nanohole arrays at deep‐subwavelength scale (6 nm) is demonstrated using a two‐step fabrication method. The nanohole arrays are formed first by the growth of a high‐quality two‐phase (i.e., Au–TiN) vertically aligned nanocomposite template, followed by selective wet‐etching of the metal (Au). Such a plasmonic nanohole film owns high epitaxial quality with large surface coverage and the structure can be tailored as either fully etched or half‐way etched nanoholes via careful control of the etching process. The chemically inert and plasmonic TiN plays a role in maintaining sharp hole boundary and preventing lattice distortion. Optical properties such as enhanced transmittance and anisotropic dielectric function in the visible regime are demonstrated. Numerical simulation suggests an extended surface plasmon mode and strong field enhancement at the hole edges. Two demonstrations, including the enhanced and modulated photoluminescence by surface coupling with 2D perovskite nanoplates and the refractive index sensing by infiltrating immersion liquids, suggest the great potential of such plasmonic nanohole array for reusable surface plasmon‐enhanced sensing applications. 

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4. Transverse cortical microtubule arrays form persistent unipolar domains in hypocotyl cells of Arabidopsis thaliana

   https://doi.org/10.1091/mbc.E25-08-0369  

   Cioffi, Timothy; Shaw, Sidney L (December 2025, Molecular Biology of the Cell)

   Bloom, Kerry (Ed.)

   Cortical microtubules influence plant cell shape by guiding cellulose deposition. Epidermal hypocotyl cells in Arabidopsis thaliana create distinct cortical microtubule array patterns to enable axial cell growth. How these array patterns are created and maintained during cell wall formation is a critical and unsolved problem in cell biology. Previous work showed that arrays aligned longitudinally with the cell's growth axis have a “split bipolar” organization, with microtubules treadmilling toward the apical or basal ends of the cell from a region of antiparallel overlap at the cell's midzone. The underlying order or architecture of these coaligned arrays prompted us to ask whether microtubules oriented transversely to the cell's axis are organized to a similar degree. Creating new fluorescently tagged End-Binding Protein 1b (EB1b) probes to circumvent gain-of-function effects observed for GFP-EB1b, we found that transverse arrays form persistent, nearly unipolar domains of microtubules treadmilling around the short axis of the cell, independent of the EB1b probe used. Our findings reveal an organizational strategy for transverse arrays distinct from that of longitudinal arrays, with implications for the mechanisms of array pattern creation and maintenance. 

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5. Controlled Nucleation and Stabilization of Ferroelectric Domain Wall Patterns in Epitaxial (110) Bismuth Ferrite Heterostructures

   https://doi.org/10.1002/adfm.202003571  

   Zhang, Yangyang; Tan, Yueze; Sando, Daniel; Chen, Long‐Qing; Valanoor, Nagarajan; Zhu, Yimei; Han, Myung‐Geun (September 2020, Advanced Functional Materials)

   Abstract Ferroelectric domain walls, topological entities separating domains of uniform polarization, are promising candidates as active elements for nanoscale memories. In such applications, controlled nucleation and stabilization of domain walls are critical. Here, using in situ transmission electron microscopy and phase‐field simulations, a controlled nucleation of vertically oriented 109° domain walls in (110)‐oriented BiFeO₃(BFO) thin films is reported. In the switching experiment, reversed domains that are nucleated preferentially at the nanoscale edges of the “crest and sag” pattern‐like electrode under external bias subsequently grow into a stable stripe configuration. In addition, when triangular pockets (with an in‐plane polarization component) are present, these domain walls are pinned to form stable flux‐closure domains. Phase field simulations show that i) field enhancement at the edges of the electrode causes site‐specific domain nucleation, and ii) the local electrostatics at the domain walls drives the formation of flux closure domains, thus stabilizing the striped pattern, irrespective of the initial configuration. The results demonstrate how flux closure pinning can be exploited in conjunction with electrode patterning and substrate orientation to achieve a desired topological defect configuration. These insights constitute critical advancements in exploiting domain walls in next generation ferroelectronic devices. 

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