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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]

Significance: Tissues like skin have a layered structure where each layer's optical properties vary significantly. However, traditional diffuse reflectance spectroscopy assumes a homogeneous medium, often leading to estimations that reflects the properties of neither layer. There's a clear need for probes that can precisely measure the optical properties of layered tissues. Aim: This paper aims to design a diffuse reflectance probe capable of accurately estimating the optical properties of bilayer tissues in the subdiffusive regime. Approach: Using Monte Carlo simulations, we evaluated key geometric factors--fiber placement, tilt angle, diameter, and numerical aperture--on optical property estimation, following the methodology in Part I. A robust design is proposed that balances accurate intrinsic optical property (IOP) calculations with practical experimental constraints. Results: The designed probe, featuring eight illumination and eight detection fibers with varying spacings and tilt angles. The estimation error of the IOP calculation for bilayer phantoms is less than 20% for top layers with thicknesses between 0.2 and 1.0 mm. Conclusion: Building on the approach from Part I and using a precise calibration, the probe effectively quantified and distinguished the IOPs of bilayer samples, particularly those relevant to early skin pathology detection and characterization. [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]

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.

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]

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.

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.

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.

The recent experimental synthesis of the monolayer γ -GeSe, characterized by its unique Mexican-hat band dispersion, has attracted considerable research interest. However, the exploration of band gap engineering in bilayer γ -GeSe and γ -SnSe through the application of strain and electric fields remains under-investigated. In this study, we demonstrate that both strain and electric fields are effective methods for band gap engineering in bilayer γ -GeSe and γ -SnSe. We have discovered that strain can not only tune the band gap but also induce a transition from an indirect to a direct band gap. Furthermore, it is observed that the band gap of bilayer γ -GeSe and γ -SnSe can be modulated by an electric field, potentially leading to a transition from semiconductor to metal. Our findings suggest that band gap engineering via strain and electric fields is a promising approach for designing nanoelectronic and optoelectronic devices based on bilayer γ -GeSe and γ -SnSe.

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.

[Display omitted] • TiO 2 and GeO 2 nanoparticles are synthesized by hydrothermal method. • TiO 2 NPs predominantly consist of the "anatase phase," and GeO 2 NPs comprise of "hexagonal α-quartz" type structure. • DSSC based on bilayer TiO 2 – GeO 2 and various binary TiO 2 – GeO 2 heterojunction film based photoanodes are investigated. • The binary TiO 2 – 0.3 wt.% GeO 2 heterojunction achieves the highest PCE of η ∼ 6.244%, among all tested devices. • The enhancement in "η" in heterojunction is due to the synergistic response of α-GeO 2 integrated with anatase-TiO 2. In this study the bilayer and binary heterojunction film-based photoanodes were fabricated using α-GeO 2 and anatase-TiO 2 nanoparticles, aiming to explore their photovoltaic capabilities for DSSCs. Results demonstrated that binary TiO 2 – 0.3 wt% GeO 2 heterojunction film based DSSC exhibits the highest PCE of η ∼ 6.244%, accompanied by a current density (J sc) of 11.570 mA cm-2 under one sun illumination as compared to bilayer TiO 2 – GeO 2 and TiO 2 film based DSSCs which displayed a PCE of 3.350% and 4.011%, respectively. It should be attributed to α-GeO 2 analogous as a barrier that swift the separation and retard the backward recombination of photogenerated charge carriers at the interfaces of oxidized dye species/redox couple and TiO 2 /redox couple, thereby boosting the kinetics of photogenerated electrons. Moreover, α-GeO 2 nanoparticles are expected to function as donors, so the donation of photogenerated electrons from the conduction band (E CB =-3.5 eV) of α-GeO 2 would enhance the density of electrons in both of LUMO (E LUMO =-3.8 eV) of N-719 dye molecules and the conduction band (E CB =-4.28 eV) of anatase-TiO 2. The demonstrated favorable capabilities indicate that α-GeO 2 potentially serves as a viable option for DSSCs. [ABSTRACT FROM AUTHOR]

Self-healing microcapsules represent a highly promising strategy for enhancing the long-term durability of materials under prolonged service conditions. Nevertheless, the industrial application of microcapsules encounters significant challenges. This is primarily due to the dilemmas involved in guaranteeing effective repair without significantly undermining the intrinsic properties of the substrate materials. Inspired by the structure of honeycombs, this paper introduces a bilayer, nested, porous self-healing microcapsule featuring an ultra-thin, rigid shell that effectively addresses the above challenges. An ultra-thin rigid shell is first constructed to enhance mechanical strength while significantly increasing the load capacity of the healing agent. Subsequently, the subcritical water treatment method is employed to etch nanoscale through-holes on the shell surface for encapsulating the healing agent. Finally, via a cross-linking reaction, a film is formed on the surface of the porous shell to seal the holes. The test results show that the loading efficiency of the microcapsules achieves 94.4 %. Moreover, while the repair efficiency is substantially enhanced, the intrinsic properties of the matrix material are maintained, and there is additionally a measurable improvement in tensile strength and insulation performance. To our knowledge, the microcapsules that significantly enhance repair efficiency while concurrently improving the properties of the matrix have not yet been reported in previous studies. Self-healing microcapsules offer an up-and-coming solution to enhancing the long-term durability and reliability of materials. However, the mechanical performance of the liquid healing agents contained within the microcapsules is often suboptimal, leading to suboptimal overall performance of the microcapsules. When microcapsules are incorporated into the matrix, it inevitably results in the degradation of both the mechanical and other properties of the material. The reason is as follows. When the material is subjected to external stress, the microcapsules fail to effectively bear the load transferred through the interface, thus becoming a weak link in the system and diminishing the overall mechanical performance of the material. The objective of researching self-healing technology is to enhance the durability of materials. However, if this technology itself adversely affects the material to an unacceptable degree, it contradicts the fundamental goals of this research. Currently, the primary strategy for enhancing the mechanical properties of traditional microcapsules and thereby reducing their detrimental effects on the matrix involves increasing the thickness of the capsule shells. However, increasing shell thickness inevitably reduces the capacity of the healing agent, thus lowering repair efficiency. Consequently, a dilemma arises: it is challenging to reduce the negative impact of microcapsules on the matrix while enhancing the efficiency of self-healing. In nature, the honeycomb is characterized by its high honey storage capacity and robustness, features that are crucial for self-healing microcapsules. Inspired by this, this study introduces a bilayer nested porous self-healing microcapsule with an ultra-thin, rigid shell. This design effectively enhances both the mechanical properties of the microcapsules and the efficiency of the encapsulated healing agents. Specifically, an ultra-thin borosilicate rigid shell is first constructed: submicron-thin walls ensure a large internal capacity, significantly boosting the loading capacity for healing agents, while the network of borate and silicate tetrahedra within the shell ensures superior mechanical properties. Following the successful fabrication of the ultra-thin rigid shell, a subcritical water treatment method is employed to etch nanoscale pores on the shell, providing access for the healing agent to be encapsulated within the shell. To prevent the healing agent from leaking out through the holes leading to the failure of microcapsules, inspired by the way bees use wax to seal their honeycombs, an oxide film is constructed on the porous shell surface through a crosslinking reaction to seal the through-holes. Ultimately, a dual-layer nested porous self-healing microcapsule with an ultra-thin, rigid shell is realized. Test results indicate that the loading efficiency of the healing agent reaches 94.4 %. When integrated into the epoxy matrix, these microcapsules not only enhance self-healing efficiency but also maintain or even improve the mechanical and insulation properties of the epoxy. A comparison is made with conventional polyurethane microcapsules to assess how each type of microcapsule influences the fundamental properties and efficacy of self-healing in the matrix material. The results show that the bilayer nested porous microcapsules are able to repair scratch damage more effectively. [Display omitted] • Drawing inspiration from the structure of honeycombs, the bilayer nested porous microcapsules feature an ultra-thin, rigid shell that significantly enhances the load capacity. This innovative design not only ensures robust mechanical properties and superior repair effectiveness but also minimizes the impact on the substrate's intrinsic properties. • This study introduces a novel microcapsule synthesis technique using an outside-in approach, distinctly different from traditional inside-out methods. This approach inspires a rethinking of microcapsule design. • The introduction of microcapsules into solid insulating materials confers self-healing capabilities while also improving the maximum tensile strength and insulation performance, effectively enhancing the overall functionality of the materials. [ABSTRACT FROM AUTHOR]

• A spectrally selective radiation infrared stealth metafilm based on a simple bilayer structure is proposed and experimentally demonstrated. • The metafilm uses the common inexpensive metal Mo instead of traditional precious metals and can be easily fabricated. • The metafilm achieves infrared stealth with low emissivity in the atmospheric window and radiation heat dissipation with high emissivity in the non-atmospheric window. In this paper, we propose and demonstrate a spectrally selective radiation infrared stealth metafilm based on a simple bilayer structure. Specifically, we use the common inexpensive metal Mo instead of traditional precious metals and achieve selective thermal radiation in the infrared band. In the atmospheric window band, the absorptivity is relatively low, which can well achieve the purpose of infrared stealth, while in the non-atmospheric window band, the absorptivity acutely increases, with a high absorptivity of 94.89 % at 6.04 μ m , which can achieve better radiation heat dissipation. The experimental results are consistent with the simulation. The average emissivity in the 8–14 μ m atmospheric window band is 0.32, while in the 5–8 μ m non-atmospheric window band is 0.80, which proves the possibility of its practical application. Meanwhile, the metafilm proposed by us can be easily fabricated and can be widely used in the control of infrared thermal radiation, thermal management, and thermal camouflage, which has a very promising application prospect. [ABSTRACT FROM AUTHOR]

Cellular membranes are composed of lipids typically organized in a double-leaflet structure. Interactions between these two leaflets - often referred to as interleaflet coupling - play a crucial role in various cellular processes. Despite extensive study, the mechanisms governing such interactions remain incompletely understood. Here, we investigate the effects of interleaflet coupling from a specific point of view, i.e. by comparing diffusive dynamics in bilayers and monolayers, focusing on potential lipid-specific interactions between opposing leaflets. Through quantitative fluorescence microscopy techniques, we characterize lipid diffusion and mean molecular area in monolayers and bilayers composed of different lipids. Our results suggest that the observed decrease in bilayer lipid diffusion compared to monolayers depends on lipid identity. Furthermore, our analysis suggests that lipid acyl chain structure and spatial configuration at the bilayer may strongly influence interleaflet interactions and dynamics in bilayers. These findings provide insights into the role of lipid structure in mediating interleaflet coupling and underscore the need for further experimental investigations to elucidate the underlying mechanisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, intelligent double-layer films were prepared using modified black rice anthocyanin (MBRA)-curcumin (CUR)-gellan gum (GG) as the inner indicator layer and sodium alginate (ALG)‑zinc oxide (ZnO) as the outer antimicrobial layer. The bilayer films were successfully prepared, as revealed by scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction measurements. The mechanical characteristics, moisture content, and water vapor resistance of GG-MBRA/CUR1@ALG-ZnO, GG-MBRA/CUR2@ALG-ZnO, and GG-MBRA/CUR3@ALG-ZnO films showed significant enhancement compared to GG-MBRA/CUR3 and ALG-ZnO films. The bilayer films exhibited excellent pH responsiveness and reacted effectively to ammonia. The outer layer significantly improved the antioxidant and antibacterial properties of the inner layer. When the films were applied to shrimp, it was found that the double-layer films not only monitored the freshness of the shrimp in real-time but also were influential in extending the shelf life of the shrimp by about 1 d. Therefore, the double-layer film demonstrated potential as a smart packaging material for real-time monitoring of meat product freshness. [Display omitted] [ABSTRACT FROM AUTHOR]

Surface instability, termed wrinkling, might occur in compressed bilayer systems constituted by an external rigid skin resting on an internal soft substrate, where wrinkling is favored by the rigidity contrast between the two layers. In this paper, the same instability mechanism is explored by considering a substrate characterized by an orthotropic elastic response. By varying the orientation of the principal axes of the substrate's material, the critical strain of wrinkling and the wrinkles' wavelength can be tuned during compression. Theoretical formulations for wrinkling are discussed along with the results obtained by linear bifurcation and geometrically nonlinear analyses carried out with two-dimensional finite element models. To experimentally validate the results, the intrinsic properties of Fused Deposition Modeling (FDM) 3D printing technology are leveraged: bilayer objects are manufactured by printing continuous outer shells (corresponding to the rigid skin) along the borders, while the inner raster is shaped with a porous infill pattern, forming a substrate with an orthotropic elastic response. [Display omitted] • Wrinkling of a compressed isotropic skin on an orthotropic substrate is studied. • A single material is used, leveraging the intrinsic properties of FDM 3D printing. • The stiffness mismatch is achieved varying the rastering orientation of the substrate. • Eigenvalue buckling analyses and experiments validate the governing equations. • Tunable wrinkling strain and wavelength are obtained. [ABSTRACT FROM AUTHOR]

Membrane-bound O -acyltransferases (MBOATs) are membrane-embedded enzymes that catalyze acyl chain transfer to a diverse group of substrates, including lipids, small molecules, and proteins. MBOATs share a conserved structural core, despite wide-ranging functional specificity across both prokaryotes and eukaryotes. The structural basis of catalytic specificity, regulation and interactions with the surrounding environment remain uncertain. Here, we combine comparative molecular dynamics (MD) simulations with bioinformatics to assess molecular and interactional divergence across the family. In simulations, MBOATs differentially distort the bilayer depending on their substrate type. Additionally, we identify lipid binding sites surrounding reactant gates in the surrounding membrane. Complementary bioinformatic analyses reveal a conserved role for re-entrant loop-2 in MBOAT fold stabilization and a key hydrogen bond bridging DGAT1 dimerization. Finally, we predict differences in MBOAT solvation and water gating properties. These data are pertinent to the design of MBOAT-specific inhibitors that encompass dynamic information within cellular mimetic environments. [Display omitted] • MBOAT subfamilies differentially distort the surrounding bilayer • Conserved residue pairs on re-entrant loop-2 stabilize the MBOAT fold • A conserved hydrogen bond interconnects the DGAT1 dimer • Solvent gating and hydration properties differ across the family Ansell et al. use molecular dynamics simulations and bioinformatic analyses to compare interactions across the MBOAT family. MBOAT subfamilies differentially interact with themselves, the surrounding membrane, and solvent environments. These data are pertinent to the design of MBOAT-specific inhibitors and family classification. [ABSTRACT FROM AUTHOR]

Bilayer (BL) two-dimensional transition metal dichalcogenides (TMDs) exhibit excellent properties in carrier mobility, state density, and room temperature stability, which attract considerable attention. However, previous efforts on synthesis BL TMDs have lacked homogeneity and control over the number of layers. Here, we demonstrate an effective and controllable approach to synthesize highly uniform 3R phase BL MoS 2 on a c-plane sapphire substrate. The number of MoS 2 layer can be controlled by adjusting the confinement distance, sapphire step height (annealing temperature), and growth temperature. These influencing factors have been thoroughly investigated. Raman and PL analyses demonstrate bilayer properties and remarkable uniformity. SHG and HAADF-STEM measurements reveal 3R stacking structure of BL MoS 2. Furthermore, field-effect-transistor (FET) devices fabricated using BL MoS 2 domains exhibit high carrier mobility and on/off ratio. This work provides an efficient method for layer-controlled MoS 2 growth and offers new insights into the growth mechanism of BL MoS 2. • The ratio of bilayer MoS 2 domains can be reach 99%. • The impacts of space distance, step height and growth temperature on bilayer MoS 2 growth have been systematically investigated. • Abundant characterization techniques were used to characterize optical properties and stacking structure of bilayer MoS 2. • BL MoS 2 FET devices exhibited excellent electronic properties. [ABSTRACT FROM AUTHOR]

Doping in transition metal dichalcogenide (TMD) has received extensive attention for its prospect in the application of photoelectric devices. Currently researchers focus on the doping ability and doping distribution in monolayer TMD and have obtained a series of achievements. Bilayer TMD has more excellent properties compared with monolayer TMD. Moreover, bilayer TMD with different stacking structures presents varying performance due to the difference in interlayer coupling. Herein, this work focuses on doping ability of dopants in different bilayer stacking structures that has not been studied yet. Results of this work show that the doping ability of V atoms in bilayer AA' and AB stacked WS 2 is different, and the doping concentration of V atoms in AB stacked WS 2 is higher than in AA' stacked WS 2 . Moreover, dopants from top and bottom layer can be distinguished by scanning transmission electron microscopy (STEM) image. Density functional theory (DFT) calculation further confirms the doping rule. This study reveals the mechanism of the different doping ability caused by stacking structures in bilayer TMD and lays a foundation for further preparation of controllable-doping bilayer TMD materials., (© 2024 Wiley‐VCH GmbH.)

The influence of geometry and electrical properties of Stone-Wales (SW) defects and an applied electric field on bilayer zigzag silicene nanoribbons (ZSiNRs) were investigated using the self-consistent charge density functional tight-binding (SCC-DFTB) method. The results show that concave deformation occurs at SW defects, leading to varying degrees of disruption in the original symmetrical structure. The overall stability of the marginal Stone-Wales (MSW) nanoribbons surpasses that of the central Stone-Wales (CSW) nanoribbons, SW-II type defects are prone to form in bilayer nanoribbons. The band gap of MSW defective nanoribbons expands significantly, realizing the transition from metallic to semi-metallic and semi-conductor properties. The electrons are transferred from the inner to the outer side of the nanoribbons, with a higher prevalence of defect nanoribbons compared to those that are perfect. The electric field intensity significantly alters the properties of both MSW-I and MSW-II defective nanoribbons. [ABSTRACT FROM AUTHOR]

[Display omitted] • Woven fabric strain sensor with a synergistic bilayer network was designed. • Ultrahigh sensitivity and wide working range were achieved simultaneously. • Gauge factor of up to 1.63 × 105 and detection range of 0 ∼ 515 %. • The strain sensor exhibited fast response/recovery (135 ms/135 ms). • Precise monitoring of various human motions and physiological signals. Flourishing flexible and wearable strain sensors still meet a challenge to realize ultrahigh sensitivity and wide working range simultaneously through a convenient strategy. Here, a strain sensor is designed based on natural rubber (NR) matrix and a bilayer structure composed of a highly stretchable liquid metal (LM) layer and a susceptible reduced graphene oxide (RGO)@carbonized bandage (CB) layer. By painting LM onto the surface of a graphene oxide (GO)-coated bandage template followed with a rapid flame pyrolysis, a dual conductive-layer woven fabric based on LM/RGO@CB was obtained. NR was then employed as an elastic substrate. Benefiting from the synergistic bilayer network and the high stretchability of the elastomer, the fabricated strain sensor exhibited ultrahigh sensitivity (gauge factor of up to 1.63 × 105), quite wide detection range (strain of 0 ∼ 515 %), low detection limit (0.25 %), fast response/recovery (135 ms/135 ms), and satisfactory durability (5700 cycles). The extraordinary strain-sensing performance allowed comprehensive monitoring of full-range (vigorous and subtle) human motions and physiological activities. This work provides a facile bilayer strategy for the preparation of high-performance strain sensors. [ABSTRACT FROM AUTHOR]

Semiconducting single-walled carbon nanotube (SWCNT) film fabrication using the dip-coating method has successfully produced a unique film with two layers of different morphologies, an upper layer of aligned SWCNT film and a lower layer of non-aligned SWCNT network film. In the upper layer, SWCNTs form SWCNT bundles of several SWCNT thicknesses, and the bundles form thin aligned SWCNT films of 2–7 nm in thickness with parallel and equally spaced bundles of SWCNTs. When a bolometer device with this bilayer film was fabricated on electrodes, the upper aligned SWCNT film was the main conductive path with a low resistivity of about 0.2 Ωcm around room temperature. The alignment film also achieved a high temperature coefficient of resistance (TCR) of more than −5%/K due to its thin thickness, which is hardly affected by the slight metallic SWCNT presence. These excellent properties of a high TCR and low resistance are advantageous for the development of innovative sensor elements. [Display omitted] • Successful fabrication of novel two-layer film of aligned and non-aligned SWCNTs. • Achievement of a high temperature coefficient of resistance (TCR) of above −5%/K. • Low resistance achieved with thin aligned SWCNT films 2–7 nm in thickness. • Demonstration of an excellent-performance bolometer with low resistance and high TCR. [ABSTRACT FROM AUTHOR]

• TiN/TiO 2 bilayers fabricated on glass by oblique angle sputtering and sol-gel deposition. • Surface morphology of the top TiO 2 layer modified by the TiN sub-layer. • Higher photocatalytic activity of TiN/TiO 2 bilayer than the TiO 2 monolayer. TiO 2 monolayer and TiN/TiO 2 bilayer coatings were deposited on soda-lime glass prepared by mixing two techniques, TiO 2 was deposited by sol-gel dip-coating and TiN film was deposited by oblique angle deposition using reactive magnetron sputtering at α=45° Structural analysis showed typical peaks of TiO 2 anatase phase and cubic (Na-Cl type) structure of TiN. Roughness value of 3 nm was obtained for the TiN/TiO 2 bilayer film with a rise and elongated grains size. It was found that the optical band gap energy decreases after coupling the TiN sub-layer which is explained by the incorporation of N atoms into TiO 2 structure. At constant UV irradiation time, the photo-degradation of methylene blue rate increased for TiN/TiO 2 film by 4 % compared to TiO 2 film. [ABSTRACT FROM AUTHOR]

Compiling hydrophobic and hydrophilic proteins to form mechanically reliable bilayer film with improved water barrier properties and hydrophobicity to replace petroleum-based standards is challenging because fabricating compatible surfaces and flexible film with interlinked interfaces is complex. The mechanical properties of gelatin and zein layers exhibited unique variations, and synergistic enhancement of bilayer properties reflected robust layer-by-layer (LBL) interactions. To overcome the problem of impaired integrated surface, viscously cross-linked zein film forming solution (FFS) by glyoxal (GX) introduced compact and closely entangled network formation with cross-linking of gelatin film. Zein surface compatibility and flexibility by GX and polyethylene glycol (PEG 400) synergized with the gelatin layer closed to compare flexible plastic materials such as PE and PP besides modulated color and transparency. Enhancing flexible formation was mechanized by acetic acid as solvent of zein solution after long-range repulsion during casting on well-manageable plasticized and cross-linked gelatin film with glutaraldehyde (GA) and PEG 400, respectively. Elongation (E%) was achieved by nearly 192% with modified tensile strength (TS) and Young's modulus (YM). Cross-linkers, especially GX, resulted in lower water solubility (WS), and joint layers resulted in controlled water vapor permeability (WVP) of bilayer films. Decreased surface roughness and WS increased water contact angle (WCA). FTIR spectroscopy, XRD analysis, DMTA, and SDS-PAGE analyzed cross-linking mode and intensity. Hence, gelatin-zein bilayer films showed significant potential for improving value-added functional properties. [Display omitted] • Zein FFS by glyoxal introduces outer compact and closely entangled network formation. • Gelatin FFS close to neutral pH casting on zein layers was avoided for bilayer. • Layer-by-layer (LBL) cross-linking improved mechanical and surface properties. • Zein layer primarily influenced the flexibility of the bilayer. • Surface compatibility and water solubility increased water contact angle. [ABSTRACT FROM AUTHOR]

Polydimethylsiloxane (PDMS) is a widely used elastomer substrate in various fields, including wearable devices, because of its diverse advantages. However, PDMS has low stretchability and lack of adhesion, thus requires additive adhesives, such as conventional tapes, which have potential to cause skin trauma. Meanwhile, polyurethane acrylate (PUA) is also a broadly used elastomer given its various advantages, such as biocompatibility and mechanical properties. This study introduces, for the first time, a novel laser process method to form an adhesive-free PDMS/PUA bilayer film. By adjusting UV laser scanning parameters, the interfacial bonding between the PDMS and PUA can be improved without additional additives. The fabricated PDMS/PUA bilayer showed high transparency, improved mechanical properties, and adhesiveness properties. Combining with PUA (as a backbone and adhesive layer) and PDMS (as a triboelectric layer), the PDMS/PUA bilayer was further used to fabricate a transparent, attachable, and stretchable PDMS/PUA-based triboelectric nanogenerator (PP-TENG) device. The transparent attachable PP-TENG successfully detected minute human motions and functioned as a virtual piano keyboard and a virtual computer keyboard when attached to an arbitrary paper. [Display omitted] • This manuscript introduces novel laser process for adhesive-free PDMS/PUA bilayer. • The PDMS/PUA bilayer exhibits high transparency and enhanced mechanical properties. • The PDMS/PUA bilayer is used for transparent, attachable, and stretchable TENG. • Adhesive-free PP-TENG is applied to human motion sensor or virtual keyboard. [ABSTRACT FROM AUTHOR]

The fluorescence anisotropy (FA) thermogram is a common technique to characterize the thermotropic phase properties and to determine the phase transition temperature of a lipid bilayer. For several biomimetic bilayer systems composed of ion pair amphiphiles (IPAs), however, the FA thermograms obtained with the 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescent probe fail to capture their phase transition behaviors. Here, we employed molecular dynamics (MD) simulation to examine the dynamics of common fluorescent probes, including DPH and 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH), and evaluated the corresponding FA signals from the probe's rotational autocorrelation functions. The resulting FA thermogram of DPH in a DPPC bilayer indeed exhibits a sigmoidal feature that correlates with the phase behavior for the membrane. In contrast, the DPH FA thermogram fails to reflect the phase transition of IPA membranes with asymmetric or short alkyl tails. Such decoupling phenomenon is attributed to (1) the inherently disordered chain packing within the IPA bilayers of short alkyl tails, or (2) the flat orientation of DPH within the IPA bilayers featuring asymmetric alkyl chains. The FA thermograms further reweighted by the ratio of DPH flat orientation in IPA bilayers show excellent agreements with experimental data, demonstrating the importance of DPH orientation. Conversely, the amphiphilic TMA-DPH can capture the structural changes near the bilayer surface during the phase transition, applicable for a variety of IPA systems. The combined results provide important insights into the phase transition behaviors of different bilayer systems and offer guidance for probe selection in FA studies. • Accurate calculations of fluorescence anisotropy thermograms of IPA bilayers using molecular dynamics simulations. • Comparing the bilayer Tm values evaluated from the Cp and FA thermograms using MD simulations. • Flat DPH orientations cause the decoupling between its FA signal and the bilayers' thermotropic phase transition. • TMA-DPH adopts only aligned orientations to capture the bilayer structural changes during the phase transitions. [ABSTRACT FROM AUTHOR]

[Display omitted] • An ultrathin bilayer membrane is fabricated from amniotic membrane and silicon. • Bilayer membrane reveals a decreased degradation and improved mechanical property. • Silicon layer makes bilayer membrane suturable with increased transparency. • Silicon/amniotic bilayer membrane improves rabbit corneal epithelial defects. 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. [ABSTRACT FROM AUTHOR]

Low-dimensional piezoelectrics have drawn attention to the realization in nano-scale devices with high integration density. A unique branch of 2D Tellurene bilayers formed of weakly interacting quasi-1D chains via van der Waals forces is found to exhibit piezoelectricity due to the semiconducting band gap and spatial inversion asymmetry. Various bilayer stackings are systematically examined using density functional theory, revealing optimal piezoelectricity when dipole arrangements are identical in each layer. Negative piezoelectricity has been observed in two of the stackings AA' and AA″ while other two stackings exhibit the usual positive piezoelectric effect. The layer-dependent 2D piezoelectricity (∣ e 222D ∣) increases with an increasing number of layers in contrast to the odd-even effect observed in h-BN and MoS 2 . Notably, the piezoelectric effect is observed in even-layered structures due to the homogeneous stacking in multilayers. Strain is found to enhance in-plane piezoelectricity by 4.5 times (-66.25 × 10 -10 C m -1 at -5.1% strain) due to the increasing difference in Born effective charges of positively and negatively charged Te-atoms under compressive biaxial strains. Moreover, out-of-plane piezoelectricity is induced by applying an external electric field, thus implying Tellurene is a promising candidate for piezoelectric sensors., (© 2024 IOP Publishing Ltd.)