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The use of softeners is essential for enhancing laundered fabrics and hair textures after washing. For these, products based on double‐tailed cationic surfactants are used to reduce friction and static electricity, resulting in softer and smoother fibers. These surfactants form lamellar phases in water, which can be turned into vesicles and other bilayer aggregates upon shearing, greatly impacting on the rheological properties of these formulations. This study aims at elucidating how some parameters of the formulation process impact bilayer structures formation and the product rheology, using di(hydrogenated tallow)dimethylammonium chloride (DHTDMAC) aqueous dispersions as model system. Small angle X‐ray scattering (SAXS) analyses revealed lamellar phases starting from 3% DHTDMAC, with a bilayer thickness of 1.90 ± 0.03 nm, indicating significant carbon chain interdigitation. At this concentration (3%), bilayers exhibited a repetition distance of 69 nm, unveiling a behavior close to the one predicted for infinite swelling, in which lamellar structures persisted even at high dilution. Temperature plays a significant role in the rheological behavior, with elevated temperatures favoring vesicle formation, resulting in reduced apparent viscosity due to lower resistance of vesicles to flow. Upon heating, differential scanning calorimetry (DSC) analyses revealed a transition from Lβ (gel) to Lα (fluid) structures between 28 and 41°C, which was further confirmed by X‐ray diffraction (XRD). Both structural and thermotropic features observed were discussed and compared to information reported for a high‐purity grade homologue of DHTDMAC, dioctadecyldimethylammonium chloride (DODAC) mixed with water. These findings deepen the understanding of fabric softener formulation and the impact of bilayer structures formation on their properties, and should be used to optimize new formulations, enhancing their overall performance and sensorial quality. [ABSTRACT FROM AUTHOR]

Self-rectifying resistive memory can reduce the complexity of crossbar array architecture for high density memory. It can replace integrated memory and selector with one self-rectifying cell. Such a simple structure can be applied for the vertical resistive memory. Both top and bottom interface between insulating layer and electrodes are crucial to achieve highly self-rectifying memory cell. In this study, bilayer devices composed of HfO2 and TiO2 were fabricated using atomic layer deposition (ALD) for the implementation of self-rectifying memory cells. The physical, chemical, and electrical properties of HfO2/TiO2 and TiO2/HfO2 sandwiched between Pt and TiN electrodes were investigated. By analyzing the conduction mechanism of bilayer devices, the higher rectification ratio of TiO2/HfO2 stack was due to the difference in height and the number of energy barriers.

To study the service performance of polymer bilayer sheets, this experimental study focuses on the thermal and mechanical characterization of sheets composed of two polymer layers (named ABS/PMMA), an Acrylonitrile–Butadiene–Styrene layer and a 15% Poly(Methyl Methacrylate) layer. These sheets are used in many industrial components subjected to thermal and mechanical strain. The studied bilayer sheets were obtained by a co-extrusion process. Thermal properties were measured through Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Mechanical behavior was determined via uniaxial tensile tests at various temperatures less than the glass transition temperature and using two strain rates of 3.33 × 10−4 s−1 and 1.66 × 10−2 s−1. Furthermore, the viscoelastic properties are determined via Dynamic Mechanical Analysis (DMA) using two frequencies. The findings revealed substantial ABS/PMMA bilayer thermal stability. The obtained glass transition temperature of this bilayer was 111 °C. Its viscoelastic behavior was described by determining the storage and loss modulus. Furthermore, the influence of temperature and strain rate parameters on the tensile behavior of the ABS/PMMA bilayer was also determined showing high dependence of mechanical behavior on these two parameters. This bilayer exhibits brittleness at room temperature and high total strain exceeding 62% at 90 °C. [ABSTRACT FROM AUTHOR]

Thermoset resins are singular materials in the field of microelectronics. Because they exhibit a high contrast of thermomechanical properties with other integrated materials like oxides, metals or silicon, polymers can threaten the mechanical integrity of stacks. Knowing polymer properties allows manufacturers to foresee the compatibility between materials and improve chipsets reliability. At a bilayer scale, the properties mismatch between the polymer film and the silicon substrate causes an overall curvature of the wafer which evolves with temperature. By comparing the thermally induced curvature of two distinct substrates with the same film, the biaxial modulus and the coefficient of thermal expansion of the film can be determined. This method can not only check the achievement of the polymer cross-linking, but also estimates their relaxation temperatures. In this article, we present the ability of this method to, not only, measure those properties in the glassy state, but also, for the first time, in the rubbery state. We also illustrate the proficiency of this approach in detecting and characterizing two successive glassy states. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive shape‐morphing hydrogels with self‐healing and tunable physiochemical properties are excellent candidates for functional building blocks of untethered small‐scale soft robots. With mechanical properties similar to soft organs and tissues, such robots enable minimally invasive medical procedures, such as cargo/cell transportation. In this work, responsive hydrogels based on zwitterionic/acrylate chemistry with self‐healing and stimuli‐responsiveness are synthesized. Such hydrogels are then judiciously cut and pasted to form hybrid constructs with predetermined swelling and elastic anisotropy. This method is used to program hydrogel constructs with predetermined 2D‐to‐3D deformation upon exposure to different environmental ionic strengths. Untethered soft robotic functionalities are demonstrated, such as actuation, magnetic locomotion, and targeted transport of soft and light cargo in flooded media. The proposed hydrogel expands the repertoire of functional materials for fabricating small‐scale soft robots. [ABSTRACT FROM AUTHOR]

Silk proteins have been highlighted in the past decade for tissue engineering (TE) and skin regeneration due to their biocompatibility, biodegradability, and exceptional mechanical properties. While silk fibroin (SF) has high structural and mechanical stability with high potential as an external protective layer, traditionally discarded sericin (SS) has shown great potential as a natural-based hydrogel, promoting cell–cell interactions, making it an ideal material for direct wound contact. In this context, the present study proposes a new wound dressing approach by developing an SS/SF bilayer construct for full-thickness exudative wounds. The processing methodology implemented included an innovation element and the cryopreservation of the SS intrinsic secondary structure, followed by rehydration to produce a hydrogel layer, which was integrated with a salt-leached SF scaffold to produce a bilayer structure. In addition, a sterilization protocol was developed using supercritical technology (sCO2) to allow an industrial scale-up. The resulting bilayer material presented high porosity (>85%) and interconnectivity while promoting cell adhesion, proliferation, and infiltration of human dermal fibroblasts (HDFs). SS and SF exhibit distinct secondary structures, pore sizes, and swelling properties, opening new possibilities for dual-phased systems that accommodate the different needs of a wound during the healing process. The innovative SS hydrogel layer highlights the transformative potential of the proposed bilayer system for biomedical therapeutics and TE, offering insights into novel wound dressing fabrication. [ABSTRACT FROM AUTHOR]

This article is concerned with the buckling of a film-substrate bilayer in a state of plane strain when it is subjected to a uni-axial compression along its free surface. Previous numerical simulations have indicated that pre-stretching the substrate in such a bilayer may lead to the formation of a mountain ridge mode as a secondary bifurcation. We present a scenario in which such a localized mode is also possible as a first bifurcation. It is first shown through a linear bifurcation analysis that by applying a pre-compression to the substrate, the stretch λ versus wavenumber k may develop a local minimum in addition to the local maximum that already exists in the absence of a pre-compression when the film is stiffer than the substrate. As a result, the λ at k = 0 may become larger than the local maximum if the pre-compression exceeds a threshold value, and hence becomes the critical stretch for bifurcation. This case is considered in this article, and it is shown through a weakly nonlinear analysis that multiple long wavelength modes may bifurcate subcritically from the uniform solution and quickly localize in the form of a mountain ridge. The solutions thus found are probably unstable, but form an essential part in the understanding of the global bifurcation behavior. It is hoped that our analytical results will guide future numerical simulations and experimental studies. [ABSTRACT FROM AUTHOR]

Fabricating heterojunctions with precisely controlled interfacial structures is crucial for exploring novel low-dimensional physics and for realizing high-performance devices. However, such capabilities are often constrained by contamination from the ambient environment or by the limitations of applicable methods and materials under vacuum conditions. In this study, MoS2/Au(111) heterostructures were fabricated by exfoliating MoS2 thin layers onto a crystallized Au(111) surface using a gold-assisted exfoliation method in an ultra-high vacuum environment. This method yields millimeter-sized monolayer or sub-millimeter-sized bilayers with contamination-free interfaces, which are unattainable for samples made in air. Scanning tunneling microscopy revealed that both the monolayer and the bilayer exhibit uniform and well-ordered moiré superlattices controlled by the twisting angle between the Au(111) surface and the MoS2 overlayer. The direct contact with the Au surface renders the monolayer MoS2 weakly metallic, while a less coupled bilayer is semiconducting, indicating a 0.54 eV Schottky barrier for the MoS2/Au(111) contact. This method is applicable to various combinations of van der Waals materials and metal surfaces. The uniform and controllable heterojunctions can serve as ideal model systems for exploring semiconductor–metal interfaces and atomic structures formed within.

Restoring the physiological function of the damaged skin is crucial due to its undeniable protective role as well as its aesthetic aspects. Herein, a novel bilayer freeze-dried scaffold comprised of allograft collagen and glycosaminoglycan (Col-GAG; the biocompatible inner layer) adhered to silicone (mechanically reinforcing component) utilizing gelatin as the bio-glue was prepared to benefit from each origin (human-derived and synthetic) advantages. The structural characterizations of the scaffolds were analyzed by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), tensile stress test, water uptake behavior, and Water Vapor Permeability (WVP). Also, the scaffolds' cytocompatibility was assessed by culturing human dermal fibroblasts (HDF) on the samples. Furthermore, the in vivo functionality was performed by implanting the scaffolds in male mice and observing the cellularization as well as neovascularization by Hematoxylin and Eosin (H&E) staining and CD31 marker. Based on the results, the potentially amorphous scaffolds were three-dimensional (3D) porous with randomly oriented interconnected pores suitable for cellular ingrowth. The application of the silicone layer resulted in resisting the extra osmotic pressure of water molecules by decreasing the water uptake ratio to 59.2 ± 0.33%, maintaining the WVP at an approximate rate of 0.1–10 mg/cm2hr, and boosting the tensile strength to 1.66 ± 0.12 MPa. The grafts provided an optimum environment for cell attachment and presented cellular viability upper than 70% after 72h. In vivo assessment exhibited improved perivascular localization, with the cell migration rate approximating 64%. The outcomes indicated that the achieved scaffold holds promise as an ideal wound dressing. [ABSTRACT FROM AUTHOR]

Self-rectifying resistive memory can reduce the complexity of crossbar array architecture for high density memory. It can replace integrated memory and selector with one self-rectifying cell. Such a simple structure can be applied for the vertical resistive memory. Both top and bottom interface between insulating layer and electrodes are crucial to achieve highly self-rectifying memory cell. In this study, bilayer devices composed of HfO2 and TiO2 were fabricated using atomic layer deposition (ALD) for the implementation of self-rectifying memory cells. The physical, chemical, and electrical properties of HfO2/TiO2 and TiO2/HfO2 sandwiched between Pt and TiN electrodes were investigated. By analyzing the conduction mechanism of bilayer devices, the higher rectification ratio of TiO2/HfO2 stack was due to the difference in height and the number of energy barriers. [ABSTRACT FROM AUTHOR]

In order to balance the stability and mobility of amorphous oxide semiconductor thin‐film transistors (AOS TFTs), we designate a stacked channel TFT structure incorporating an electron relaxation layer (CRL) and an electron transport layer (CTL). Rich In‐ITZO is chosen as the CTL, and a rich Ga‐IGZO material with a short photogenerated electron lifetime served as the CRL. Bilayer TFTs with CRL/CTL ratios of 5/20, 10/20, 15/20, 20/20, and 30/20 nm are prepared. The results reveal that the CRL/CTL stacked structure effectively enhances stability while maintaining high mobility. With an increase in CTL thickness, the TFT mobility also increases. Ultimately, three groups of devices with both high mobility and stability are fabricated: 10/20 TFT with a field‐effect mobility (μFE) of approximately 48.58 cm2V-1s-1 and a negative bias illumination stress (NBIS) threshold voltage shift (|ΔVth|) of around ‐1.14 V; 15/20 TFT with µFE~54.08 cm2V-1s-1 and NBIS |ΔVth|~ ‐2.35 V; and 20/20 TFT with µFE~65.98 cm2V-1s-1 and NBIS |ΔVth|~ ‐2.07 V. This suggests that the CRL/CTL structure can achieve high‐performance TFTs suitable for various display applications. [ABSTRACT FROM AUTHOR]

Valleytronic materials can provide new degrees of freedom to future electronic devices. In this work, the concepts of the ferrovalley metal (FVM) and valley gapless semiconductor (VGS) are proposed, which can be achieved in valleytronic bilayer systems by electric field engineering. In valleytronic bilayer systems, the interaction between out-of-plane ferroelectricity and A-type antiferromagnetism can induce layer-polarized anomalous valley Hall (LP-AVH) effect. The K and −K valleys of FVM are both metallic, and electron and hole carriers simultaneously exist. In the extreme case, the FVM can become VGS by analogizing spin gapless semiconductor (SGS). Moreover, it is proposed that the valley splitting enhancement and valley polarization reversal can be achieved by electric field engineering in valleytronic bilayer systems. Taking the bilayer RuBr2 as an example, our proposal is confirmed by the first-principle calculations. The FVM and VGS can be achieved in bilayer RuBr2 by applying electric field. With appropriate electric field range, increasing electric field can enhance valley splitting, and the valley polarization can be reversed by flipping electric field direction. To effectively tune valley properties by electric field in bilayer systems, the parent monolayer should possess out-of-plane magnetization, and have large valley splitting. Our results shed light on the possible role of electric field in tuning valleytronic bilayer systems, and provide a way to design the ferrovalley-related material by electric field. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop buccal film formulations containing metoclopramide hydrochloride monohydrate (MCP) with and without a backing layer and to evaluate their release properties and physiochemical stability. The crystallization of MCP in the polymer matrix was monitored with image analysis techniques for rapid and scalable observation. The results showed that the addition of a protective layer and its thickness significantly affected the release rate and crystallization behavior of MCP in the formulations. The crystallization of MCP increased over time, and certain formulations showed higher susceptibility to crystallization. To understand the factors affecting the crystallization of MCP, the relationship between the viscosity and pH of the casting solution was examined, but no significant correlation was found. A significant correlation was observed between the plasticizer concentration and the physical state of MCP. Through a systematic Design of Experiment (DOE) approach, an optimal formulation was devised, successfully preventing crystallization of the active ingredient. However, enhancing the overall chemical stability of the formulated product remains a challenge. [ABSTRACT FROM AUTHOR]

Using the polymerization-induced phase separation (PIPS) method, bilayer polymer-dispersed liquid crystal (PDLC) films with a PDLC-PVA-PDLC structure were prepared in this work. It was found that all PDLC performance indexes were affected by polymer mesh size after comparing the microscopic morphology and electro-optical properties of samples with different monomer ratios. Gd2O3 nanoparticles and rhodamine B base fluorescent dyes introduced into the bilayer PDLC optimized the samples' electro-optical properties and developed new functionalities. In addition, the bilayer PDLC doped with Gd2O3 and rhodamine B base held excellent progressive driving functions as well as stable durability properties. Samples doped with Gd2O3 nanoparticles and rhodamine B base also produced excellent anti-counterfeiting effects under UV irradiation at different angles, further exploiting the application potential of PDLC. [ABSTRACT FROM AUTHOR]

<>Two dimensional (2D) materials are used to manufacture the various gadgets. Their properties are therefore appealing. In the present work, we have studied the structural, electronic, and magnetic properties of 2D bilayer hexagonal-Boron Nitride (h-BN), single B vacancy defect on h-BN (B-hBN), single N vacancy defect on h-BN (N-hBN), water adsorption; on B-hBN (w-B-hBN) and on N-hBN (w-N-hBN), materials by spin-polarized density functional theory (DFT) methods employing Quantum ESPRESSO (QE) computational tools. The structural stability of the h-BN, B-hBN, N-hBN, w-B-hBN, & w-N-hBN materials has been investigated by determining their minimum ground state energy and binding energy, and found that they are stable materials. The pristine h-BN bilayer supercell structure is also found to be more compact than other defective configurations. By analyzing the band structures and density of states (DoS) plots of these materials, we have examined their electronic properties, and found that pristine h-BN has a broad bandgap, whereas B-hBN, N-hBN, w-B-hBN, & w-N-hBN exhibit semiconducting nature. The DoS and partial density of states (PDoS) computations of the considered materials are used to study their magnetic properties. It is found that pristine h-BN is a non-magnetic, and B-hBN, N-hBN, w-B-hBN & w-N-BN are magnetic materials. Therefore, vacancy defects on pristine h-BN, and water adsorption on vacancy defected h-BN materials cause it to change from non-magnetic to magnetic. They could find use in the domain of device applications.

Selective preparation of two-dimensional polymers (2DPs) and supramolecular polymers (2DSPs) with defined thickness is crucially important for controlling and maximizing their functions, yet it has remained as a synthetic challenge. In the past decade, several approaches have been developed to allow selective preparation of discrete monolayer 2DPs and 2DSPs. Recently, crystal exfoliation and self-assembly strategies have been employed to successfully prepare bilayer 2DP and 2DSP, which represent the first step towards the controlled "growth" of 2D polymers from the thinnest monolayers to thicker few-layers along the third dimension. This Concept review discusses the concept of accurate synthesis of 2D polymers with defined layers. Advances in this research area will pave the way to rational synthetic strategies for 2D polymers with controlled thickness.

Coarse-grained molecular dynamic simulations are employed to investigate the spatiotemporal evolution of vesicles (polymersomes) via self-assembly of randomly distributed amphiphilic diblock copolymers PB-PEO (Poly(Butadiene)-b-Poly(Ethylene Oxide)) in water. The vesiculation pathway consists of several intermediate structures, such as spherical/rodlike aggregates, wormlike micelles, lamellae, and cavities. The lamella-to-vesicle transition occurs at a constant aggregation number and is accompanied by a reduction in the solvent-accessible surface area. Simulation predictions are in qualitative agreement with the mechanism of vesicle formation in which the unfavorable hydrophobic interactions between water molecules and polymer segments, along the edge of the lamella, are eliminated at the expense of gaining curvature energy. However, rod–lamella–vesicle transition is accompanied by an increase in copolymer packing density. Hence, the change in the surface area accompanying vesiculation predicted by the simulations is significantly lower than theoretical estimates. Changes in information entropy, quantified by the expectation of the logarithm of the probability distribution function of the segmental stretch parameter s, defined as the difference between the maximum and instantaneous segmental extension, are statistically insignificant along the vesiculation pathway. For rods, lamellae, and polymersomes, s follows a log normal distribution. This is explained based on the configurational dynamics of a single diblock chain in water. [ABSTRACT FROM AUTHOR]

Stretchable strain sensors in motion detection, health monitoring, and human-machine interfaces are limited by device sensitivity, linearity, hysteresis, stability, and reproducibility in addition to stretchability. Engineering defect structures in sensing material is an effective approach in modulating the material's physical properties, particularly those associated with mechanical responses. Here, we demonstrate that bilayers of carbon nanotubes deposited on an elastomer substrate are mechanically coupled. The microcrack size, density, and distribution in the nanotube thin film can be engineered through uniaxial tensile training to exhibit highly tunable and stable piezoresistive responses with sensitivity, linearity, range, and reproducibility. These responses far exceeding those in uniform metallic films, patterned structures, and composites. In addition, numerical analyses performed on a two-dimensional network model of the cracked nanotube film provide quantitative explanations of how crack configuration, and evolvement under strain, lead to the significant enhancements in stretchable sensor performance using current bilayer structures. [ABSTRACT FROM AUTHOR]

In this paper, the bilayer polymer-dispersed liquid crystals possessing a PDLC-PVA-PDLC structure were prepared by integrating two monolayer PDLCs. The effect of the polymer mesh size on the electro–optical properties of a bilayer PDLC was investigated by comparing the micro-morphology and electro–optical curves under different polymerization conditions. In addition, the impact of doping MoO2 nanoparticles with surface modification on the comprehensive performance of the bilayer PDLC was further researched. The contrast ratio of the bilayer PDLC prepared under the optimal conditions was improved by more than 90% and still maintained excellent progressive driving performance. Therefore, the development of a bilayer PDLC with optimal electro-optical properties will significantly enhance the technological prospects for the application of PDLC-based devices in smart windows, displays, and flexible devices. [ABSTRACT FROM AUTHOR]

In the present work, the electronic, optical, and nano structural properties of boron nitride samples (in monolayer, bilayer and bulk form) were determined with the help of density functional theory (DFT) and calculations using the Siesta package and the generalized gradient approximation (GGA). - PBE) has been discussed. It is found that the bond length, bond angles, and curvature values of boron nitride are almost the same in monolayer, bilayer, and bulk states. Of course, these structures are considered to have planar forms. Considering the existence of the low band gap energy between the bottom of the conduction band and the maximum of the valence band, (although the size of the bandgap decreases with the increase in the number of layers), it can be concluded that the samples are semiconductors. Since there is a relationship between refractive index, magnetic permeability, and electrical permeability (magnetic parameters are not discussed in the present work), dielectric function, reflection coefficient, absorption coefficient, and refractive index are also investigated. The two real and imaginary components of the dielectric function are important in the properties of materials in terms of nanocomposites. Here, special attention is paid to the main peak in the real part of the dielectric constant. [ABSTRACT FROM AUTHOR]

The spin Heisenberg antiferromagnet on the frustrated triangular lattice is known to feature various zero-field ground-state phases, consisting of skyrmion lattice phase and the multiple spin spiral ground states as well as a spiral spin state. Using steepest-descent method we investigate the properties of this system and the related ferroelectric lattice in the presence of a finite magnetoelectric coupling, addressing both the ground-state phase diagram. In addition to the zero-field ground states, we find at moderate values magnetoelectric coupling a skyrmion lattice phase. We show that magnetic frustration induces the creation and emergence of a skyrmion lattice at moderate values of Dzyaloshinskii–Moriya interaction and interface magnetoelectric coupling with adjacent ferroelectric layer. At intermediate Dzyaloshinskii–Moriya interaction, we identify that the skyrmion lattice states are stabilized by a spin anisotropy. [ABSTRACT FROM AUTHOR]

Abstract Nonreciprocal interlayer coupling is difficult to practically implement in bilayer non-Hermitian topological photonic systems. In this work, we identify a similarity transformation between the Hamiltonians of systems with nonreciprocal interlayer coupling and on-site gain/loss. The similarity transformation is widely applicable, and we show its application in one- and two-dimensional bilayer topological systems as examples. The bilayer non-Hermitian system with nonreciprocal interlayer coupling, whose topological number can be defined using the gauge-smoothed Wilson loop, is topologically equivalent to the bilayer system with on-site gain/loss. We also show that the topological number of bilayer non-Hermitian C6v-typed domain-induced topological interface states can be defined in the same way as in the case of the bilayer non-Hermitian Su–Schrieffer–Heeger model. Our results show the relations between two microscopic provenances of the non-Hermiticity and provide a universal and convenient scheme for constructing and studying nonreciprocal interlayer coupling in bilayer non-Hermitian topological systems. This scheme is useful for observation of non-Hermitian skin effect in three-dimensional systems. Graphical Abstract

Silk proteins have been highlighted in the past decade for tissue engineering (TE) and skin regeneration due to their biocompatibility, biodegradability, and exceptional mechanical properties. While silk fibroin (SF) has high structural and mechanical stability with high potential as an external protective layer, traditionally discarded sericin (SS) has shown great potential as a natural-based hydrogel, promoting cell–cell interactions, making it an ideal material for direct wound contact. In this context, the present study proposes a new wound dressing approach by developing an SS/SF bilayer construct for full-thickness exudative wounds. The processing methodology implemented included an innovation element and the cryopreservation of the SS intrinsic secondary structure, followed by rehydration to produce a hydrogel layer, which was integrated with a salt-leached SF scaffold to produce a bilayer structure. In addition, a sterilization protocol was developed using supercritical technology (sCO2) to allow an industrial scale-up. The resulting bilayer material presented high porosity (>85%) and interconnectivity while promoting cell adhesion, proliferation, and infiltration of human dermal fibroblasts (HDFs). SS and SF exhibit distinct secondary structures, pore sizes, and swelling properties, opening new possibilities for dual-phased systems that accommodate the different needs of a wound during the healing process. The innovative SS hydrogel layer highlights the transformative potential of the proposed bilayer system for biomedical therapeutics and TE, offering insights into novel wound dressing fabrication.

Amniotic membrane (AM) is an effective and widely used dressing in ocular injuries to reconstruct the cornea. Due to its low mechanical strength, high biodegradation rate, and difficult handling, its usage in medical interventions remains challenging. In this study, decellularized AM was covered with an ultrathin layer of Polydimethylsiloxane (PDMS) through a spinning method, which in turn resulted in an ultrathin (less than 80 µm in thickness) bilayer corneal wound dressing membrane with improved mechanical behavior and transparency. The biomechanical, biological, and antibacterial properties of the bilayer membranes were measured both in vitro and in vivo. The optimized microsized membrane was applied on a corneal defect wound created in a rabbit model to evaluate the corneal healing. The results demonstrated a significant decrease in degradation rate, improved mechanical properties, and AM/PDMS transparency compared with AM. The corneal transparency improved until 21 days post-surgery in AM/PDMS group. Histological evaluations revealed that AM/PDMS had better epithelial delaminated cell morphology. The results of the RT-PCR showed a significant increase in MMP9, a significant decrease in Col1A1, TGF-β1, TNF-α and IL-6 in both AM and AM/PDMS compared with control wounds. This study suggessts AM/PDMS membrane as an excellent corneal wound dressing.

Introduction Liposomes have been used as carriers for vaccine adjuvants and antigens due to their inherent biocompatibility and versatility as delivery vehicles. Two vial admixture of protein antigens with liposome-formulated immunostimulatory adjuvants has become a broadly used clinical vaccine preparation approach. Compared to freely soluble antigens, liposome-associated forms can enhance antigen delivery to antigen-presenting cells and co-deliver antigens with adjuvants, leading to improved vaccine efficacy. Areas covered Several antigen-capture strategies for liposomal vaccines have been developed for proteins, peptides, and nucleic acids. Specific antigen delivery methodologies are discussed, including electrostatic adsorption, encapsulation inside the liposome aqueous core, and covalent and non-covalent antigen capture. Expert opinion Several commercial vaccines include active lipid components, highlighting an increasingly prominent role of liposomes and lipid nanoparticles in vaccine development. Utilizing liposomes to associate antigens offers potential advantages, including antigen and adjuvant dose-sparing, co-delivery of antigen and adjuvant to immune cells, and enhanced immunogenicity. Antigen capture by liposomes has demonstrated feasibility in clinical testing. New antigen-capture techniques have been developed and appear to be of interest for vaccine development.

BFO possess high remnant polarization (∼100 μC/cm2) and low direct band gap (∼2.7 eV) having potential for photovoltaic (PV) applications. In the present work, WO3 insulating layer is utilized with BFO and BFO/WO3 bilayer thin film structure is fabricated for reducing the leakage current along with possessing the low band gap and high ferroelectric polarization. In BFO/WO3 bilayer structure, the WO3 nanostructured thin film layer was fabricated utilizing rf-magnetron sputtering technique under the optimized parameters while BFO thin film layer was fabricated by altering the incident energy of excimer laser (150 mJ − 250 mJ) in Pulsed Laser deposition technique. BFO/WO3 bilayer structure prepared at 200 mJ laser energy demonstrated the superior ferroelectric properties (Ps = 63.24 µC/cm2 and Pr = 25.94 µC/cm2) with high values of short circuit photocurrent density (Jsc = ∼18 mA/cm2) and open-circuit voltage (Voc = ∼320 mV) under the UV illumination of Intensity = 160 mW/cm2 and λ = 355 nm. Obtained results suggest the utilization of prepared BFO/WO3 bilayer thin film structures on future novel energy harvesting purposes.

Nonreciprocal interlayer coupling is difficult to practically implement in bilayer non-Hermitian topological photonic systems. In this work, we identify a similarity transformation between the Hamiltonians of systems with nonreciprocal interlayer coupling and on-site gain/loss. The similarity transformation is widely applicable, and we show its application in one- and two-dimensional bilayer topological systems as examples. The bilayer non-Hermitian system with nonreciprocal interlayer coupling, whose topological number can be defined using the gauge-smoothed Wilson loop, is topologically equivalent to the bilayer system with on-site gain/loss. We also show that the topological number of bilayer non-Hermitian C6v-typed domain-induced topological interface states can be defined in the same way as in the case of the bilayer non-Hermitian Su–Schrieffer–Heeger model. Our results show the relations between two microscopic provenances of the non-Hermiticity and provide a universal and convenient scheme for constructing and studying nonreciprocal interlayer coupling in bilayer non-Hermitian topological systems. This scheme is useful for observation of non-Hermitian skin effect in three-dimensional systems. [ABSTRACT FROM AUTHOR]

Simple Summary: Scramblases are proteins that translocate phospholipids from one leaflet of a membrane bilayer to the other. Our work identifies that a well-characterized protein from Escherichia coli, lactose permease, also displays lipid scrambling activity. The scrambling function is independent of LacY's proton-coupled lactose transport activity and involves two amino acid residues located near the membrane surface. Lactose permease (LacY) from Escherichia coli belongs to the major facilitator superfamily. It facilitates the co-transport of β-galactosides, including lactose, into cells by using a proton gradient towards the cell. We now show that LacY is capable of scrambling glycerophospholipids across a membrane. We found that purified LacY reconstituted into liposomes at various protein to lipid ratios catalyzed the rapid translocation of fluorescently labeled and radiolabeled glycerophospholipids across the proteoliposome membrane bilayer. The use of LacY mutant proteins unable to transport lactose revealed that glycerophospholipid scrambling was independent of H+/lactose transport activity. Unexpectedly, in a LacY double mutant locked into an occluded conformation glycerophospholipid, scrambling activity was largely inhibited. The corresponding single mutants revealed the importance of amino acids G46 and G262 for glycerophospholipid scrambling of LacY. [ABSTRACT FROM AUTHOR]

The performance of organic‐inorganic hybrid solar cells (HSCs) can be improved by modifying the hole transport layer (HTL). Poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is the most active HTL material in organic‐inorganic HSCs and has been widely studied. Nevertheless, charge transfer in PEDOT:PSS is limited and inefficient due to the presence of the weak ionic conductor PSS. Moreover, the working function of the PEDOT:PSS film and the passivation of the PSS at the Si/PEDOT:PSS interface play a crucial role in carrier separation. The focus of this work is to explore a universal modification method to simultaneously achieve improved charge transport and interfacial passivation capability when using PEDOT:PSS as HTL. By combining bilayer design and simple solution posttreatment, the direct current conductivity (σdc) and work function of the HTL based on PEDOT:PSS are increased to 765 S cm−1 and 5.00 eV, respectively. The organic‐inorganic HSCs prepared using this approach achieve a photovoltaic conversion efficiency (PCE) of 12.33%, achieving a 16.54% improvement over untreated devices. [ABSTRACT FROM AUTHOR]

[Display omitted] Manipulation of light has been proved to be a promising strategy to increase light harvesting in solar-to-chemical energy conversion, especially in photocatalysis. Inverse opal (IO) photonic structures are highly promising for light manipulation as their periodic dielectric structures enable them to slow down light and localize it within the structure, thereby improving light harvesting and photocatalytic efficiency. However, slow photons are confined to narrow wavelength ranges and hence limit the amount of energy that can be captured through light manipulation. To address this challenge, we synthesized bilayer IO TiO 2 @BiVO 4 structures that manifested two distinct stop band gap (SBG) peaks, arising from different pore sizes in each layer, with slow photons available at either edge of each SBG. In addition, we achieved precise control over the frequencies of these multi-spectral slow photons through pore size and incidence angle variations, that enabled us to tune their wavelengths to the electronic absorption of the photocatalyst for optimal light utilization in aqueous phase visible light photocatalysis. This first proof of concept involving multi-spectral slow photon utilization enabled us to achieve up to 8.5 times and 2.2 times higher photocatalytic efficiencies than the corresponding non-structured and monolayer IO photocatalysts respectively. Through this work, we have successfully and significantly improved light harvesting efficiency in slow photon-assisted photocatalysis, the principles of which can be extended to other light harvesting applications. [ABSTRACT FROM AUTHOR]

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RRAM devices operating based on the creation of conductive filaments via the migration of oxygen vacancies are widely studied as promising candidates for next-generation memory devices due to their superior memory characteristics. However, the issues of variation in the resistance state and operating voltage remain key issues that must be addressed. In this study, we propose a TaOx/SiO2 bilayer device, where the inserted SiO2 layer localizes the conductive path, improving uniformity during cycle-to-cycle endurance and retention. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) confirm the device structure and chemical properties. In addition, various electric pulses are used to investigate the neuromorphic system properties of the device, revealing its good potential for future memory device applications. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of the rolling process's impact on the formability and mechanical characteristics of the AA 1050/Mg AZ31B bilayer sheet manufactured by explosive welding. Different thicknesses of composite bilayer sheets can be achieved by the work hardening of the explosive-welded Al/Mg composite sheet. The most important point is the simultaneous rolling process's impact on the formability and mechanical characteristics of the bilayer sheet. In this research, Al/Mg bilayer sheet was first prepared by an explosive welding technique. Then, it was cooled down to room temperature in the furnace for 24 h after being annealed for 2 h at 250 °C. The rolling process was performed with reduction ratios of 10 and 20%. The strength, elongation, stress–strain diagram, and forming limit diagram, as well as the microstructural examinations, are compared in the three cases of unrolled bilayer sheets and rolled bilayer sheets with reduction ratios of 10 and 20%. The results show an increase in strength and a decrease in elongation after the rolling process of the bilayer sheets. Moreover, the strength also rises with an increase in the reduction ratio. Besides the strength enhancement, the sheet hardness is also improved due to the rolling process. The hardness improvement in the interface can be associated with forming of brittle intermetallic compounds. The rolling process also causes a drop in the forming limit diagram. Moreover, the formability is decreased by increasing the reduction ratio. The respective reduction of 25 and 49% are observed in FLD0 values for the reduction ratios of 10 and 20% as compared to the unrolled bilayer sheet. [ABSTRACT FROM AUTHOR]

This work investigates electro-static potential and electron density distributions of a bilayer system. In calculations, a self-consistent numerical method is used to solve the three-dimensional Poisson equation. Firstly, an experimental heterostructure is defined to generate the wafer configuration. Secondly, the distance between the two electron gas layers was varied. It is observed that at the tunneling limit of separation (∼ nm), the spatial distribution of electrons is significantly different. Following step, the effects of the metallic gate defined on the heterostructure and the potential vary applied to this metallic gate on the spatial distribution of electrons were investigated.The calculations represent that the bottom layer is unaffected for the voltage values applied to the metallic gate. At a particular gate voltage value, the top layer is completely depleted. In the locally depleted electron regions in the top layer, the electrons in the corresponding regions in the bottom layer are affected by the gate potential. This study provides significant results and therefore will be leading for current and future studies. [ABSTRACT FROM AUTHOR]

Abstract Treatment of complete loss of skin thickness requires expensive cellular materials and limited skin grafts used as temporary coverage. This paper presents an acellular bilayer scaffold modified with polydopamine (PDA), which is designed to mimic a missing dermis and a basement membrane (BM). The alternate dermis is made from freeze-dried collagen and chitosan (Coll/Chit) or collagen and a calcium salt of oxidized cellulose (Coll/CaOC). Alternate BM is made from electrospun gelatin (Gel), polycaprolactone (PCL), and CaOC. Morphological and mechanical analyzes have shown that PDA significantly improved the elasticity and strength of collagen microfibrils, which favorably affected swelling capacity and porosity. PDA significantly supported and maintained metabolic activity, proliferation, and viability of the murine fibroblast cell lines. The in vivo experiment carried out in a domestic Large white pig model resulted in the expression of pro-inflammatory cytokines in the first 1–2 weeks, giving the idea that PDA and/or CaOC trigger the early stages of inflammation. Otherwise, in later stages, PDA caused a reduction in inflammation with the expression of the anti-inflammatory molecule IL10 and the transforming growth factor β (TGFβ1), which could support the formation of fibroblasts. Similarities in treatment with native porcine skin suggested that the bilayer can be used as an implant for full-thickness skin wounds and thus eliminate the use of skin grafts.

The objective of this study was to develop buccal film formulations containing metoclopramide hydrochloride monohydrate (MCP) with and without a backing layer and to evaluate their release properties and physiochemical stability. The crystallization of MCP in the polymer matrix was monitored with image analysis techniques for rapid and scalable observation. The results showed that the addition of a protective layer and its thickness significantly affected the release rate and crystallization behavior of MCP in the formulations. The crystallization of MCP increased over time, and certain formulations showed higher susceptibility to crystallization. To understand the factors affecting the crystallization of MCP, the relationship between the viscosity and pH of the casting solution was examined, but no significant correlation was found. A significant correlation was observed between the plasticizer concentration and the physical state of MCP. Through a systematic Design of Experiment (DOE) approach, an optimal formulation was devised, successfully preventing crystallization of the active ingredient. However, enhancing the overall chemical stability of the formulated product remains a challenge.

Using the polymerization-induced phase separation (PIPS) method, bilayer polymer-dispersed liquid crystal (PDLC) films with a PDLC-PVA-PDLC structure were prepared in this work. It was found that all PDLC performance indexes were affected by polymer mesh size after comparing the microscopic morphology and electro-optical properties of samples with different monomer ratios. Gd2O3 nanoparticles and rhodamine B base fluorescent dyes introduced into the bilayer PDLC optimized the samples’ electro-optical properties and developed new functionalities. In addition, the bilayer PDLC doped with Gd2O3 and rhodamine B base held excellent progressive driving functions as well as stable durability properties. Samples doped with Gd2O3 nanoparticles and rhodamine B base also produced excellent anti-counterfeiting effects under UV irradiation at different angles, further exploiting the application potential of PDLC.

The microstructure factor (R*) of the PECVD-grown intrinsic amorphous silicon (i-a-Si:H) layer plays a crucial role in crystalline silicon (c-Si) surface passivation and charge carrier transport in silicon heterojunction (SHJ) solar cells. In this work, we have used stack of i-a-Si:H passivation layers deposited at two different temperatures to improve the c-Si surface passivation by minimizing the interface defect density at the a-Si/c-Si interface. The initial i1-a-Si:H layer is deposited on the c-Si at ~ 150 °C with a high R*, and the second i2-a-Si:H layer is deposited at 230 °C with a low R*. Ex-situ ellipsometry analysis of i-a-Si:H layers provided information related to the void fraction of the thin films due to modification in the Si–H≥2 and Si–H bonding environment, which plays a vital role in atomic H migration towards i-a-Si:H/c-Si interface. Combining the low- and high-temperature i-a-Si:H layer stack enhanced the cell precursor passivation to ~ 2.1 ms with an implied Voc of ~ 714 mV. Furthermore, implementing the optimized thickness (2 nm + 8 nm) of the i-a-Si:H stack (with 40% void fraction in i1-a-Si:H layer) in the device has led to the power conversion efficiency of ~ 19.06%. [ABSTRACT FROM AUTHOR]

Chemical vapor deposition (CVD) approach offers a controllable strategy for preparing large‐area and high‐quality few‐layer (mainly bilayer or trilayer) twisted or untwisted two‐dimensional (2D) materials, and is predicted to boost the development of 2D materials from laboratory research to industrial applications. [ABSTRACT FROM AUTHOR]

Abstract The influence of molecular fragmentation and parameter settings on a mesoscopic dissipative particle dynamics (DPD) simulation of lamellar bilayer formation for a C10E4/water mixture is studied. A “bottom-up” decomposition of C10E4 into the smallest fragment molecules (particles) that satisfy chemical intuition leads to convincing simulation results which agree with experimental findings for bilayer formation and thickness. For integration of the equations of motion Shardlow’s S1 scheme proves to be a favorable choice with best overall performance. Increasing the integration time steps above the common setting of 0.04 DPD units leads to increasingly unphysical temperature drifts, but also to increasingly rapid formation of bilayer superstructures without significantly distorted particle distributions up to an integration time step of 0.12. A scaling of the mutual particle–particle repulsions that guide the dynamics has negligible influence within a considerable range of values but exhibits apparent lower thresholds beyond which a simulation fails. Repulsion parameter scaling and molecular particle decomposition show a mutual dependence. For mapping of concentrations to molecule numbers in the simulation box particle volume scaling should be taken into account. A repulsion parameter morphing investigation suggests to not overstretch repulsion parameter accuracy considerations.

Since the traditional bending theory of bilayers was mainly for linear elastic materials with the assumption of infinitesimal deformation, here we study the bending of a bilayer soft strip with large deformation. The strip under investigation is comprised of an active layer and a passive layer, where only the active layer is assumed to be subjected to an isotropic volumic expansion. A bending theory for the large deformation of the strip is then developed. The subsequent analysis indicates that our theoretical predictions agree well with the finite element simulation, which, however, can significantly diverge from those predicted by the traditional theory under certain circumstances. With our theory, it is also shown that there exists an optimal modulus ratio or thickness ratio for a bilayer strip to achieve a maximal curvature. We suggest that our theory may greatly facilitate the design of soft bilayer strips that can be potentially employed in varied fields. [ABSTRACT FROM AUTHOR]

Background: In vivo mechanical characterisation of biological soft tissue is challenging, even under moderate quasi-static loading. Clinical application of suction-based methods is hindered by usual assumptions of tissues homogeneity and/or time-consuming acquisitions/postprocessing. Objective: Provide practical and unexpensive suction-based mechanical characterisation of soft tissues considered as bilayered structures. Inverse identification of the bilayers' Young's moduli should be performed in almost real-time. Methods: An original suction system is proposed based on volume measurements. Cyclic partial vacuum is applied under small deformation using suction cups of aperture diameters ranging from 4 to 30 mm. An inverse methodology provides both bilayer elastic stiffnesses, and optionally the upper layer thickness, based on the interpolation of an off-line finite element database. The setup is validated on silicone bilayer phantoms, then tested in vivo on the abdomen skin of one healthy volunteer. Results: On bilayer silicone phantoms, Young's moduli identified by suction or uniaxial tension presented a relative difference lower than 10 % (upper layer thickness of 3 mm). Preliminary tests on in vivo abdomen tissue provided skin and underlying adipose tissue Young's Moduli at 54 kPa and 4.8 kPa respectively. Inverse identification process was performed in less than one minute. Conclusions: This approach is promising to evaluate elastic moduli in vivo at small strain of bilayered tissues. [ABSTRACT FROM AUTHOR]

Treatment of complete loss of skin thickness requires expensive cellular materials and limited skin grafts used as temporary coverage. This paper presents an acellular bilayer scaffold modified with polydopamine (PDA), which is designed to mimic a missing dermis and a basement membrane (BM). The alternate dermis is made from freeze-dried collagen and chitosan (Coll/Chit) or collagen and a calcium salt of oxidized cellulose (Coll/CaOC). Alternate BM is made from electrospun gelatin (Gel), polycaprolactone (PCL), and CaOC. Morphological and mechanical analyzes have shown that PDA significantly improved the elasticity and strength of collagen microfibrils, which favorably affected swelling capacity and porosity. PDA significantly supported and maintained metabolic activity, proliferation, and viability of the murine fibroblast cell lines. The in vivo experiment carried out in a domestic Large white pig model resulted in the expression of pro-inflammatory cytokines in the first 1–2 weeks, giving the idea that PDA and/or CaOC trigger the early stages of inflammation. Otherwise, in later stages, PDA caused a reduction in inflammation with the expression of the anti-inflammatory molecule IL10 and the transforming growth factor β (TGFβ1), which could support the formation of fibroblasts. Similarities in treatment with native porcine skin suggested that the bilayer can be used as an implant for full-thickness skin wounds and thus eliminate the use of skin grafts. [ABSTRACT FROM AUTHOR]