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Electronic tattoo, capable of imperceivably acquiring bio‐electrical signals from the body, is broadly applied in healthcare and human‐machine interface. Tattoo substrate, the foundation of electronic tattoo, is expected to be mechanically mimetic to skin, adhesive, and breathable, and yet remains highly challenging to achieve. Herein, the study mimics human skin and design a breathable, adhesive, and mechanically skin‐like super tattoo substrate based on an ultra‐thin film (≈2 µm). Similar to skin, super tattoo demonstrates strain‐adaptive stiffening properties with high tear energy (5.4 kJ·m−2) and toughness (1.3 MJ·m−3). Superior to skin, it exhibits high adhesion, ionic conductivity, and permeability. A variety of conductive electrodes can be processed on it, showing the universality toward an ideal platform for electronic tattoo with stable and low contact impedance. Super tattoo‐based electrodes can imperceivably and accurately monitor weak electromyography (EMG) of swallowing on the junction, providing effective guidance for rehabilitation training of dysphagia. [ABSTRACT FROM AUTHOR]

The polyphenylene sulfide (PPS) mesh-based polysulfone (PSF)-zirconia (ZrO 2) composite diaphragm represents a new type of high-performance diaphragm for alkaline water electrolysis hydrogen production, offering low area resistance and high chemical stability. In this study, composite diaphragms with excellent performance are prepared using preheated compression molding, phase inversion precipitation, and vacuum stirring degassing techniques. The comprehensive performance of the prepared diaphragm is compared to that of the commercial Zirfon® diaphragm. The results indicate that the prepared composite diaphragm, with a thickness of 140 μm, exhibits excellent performance. Compared to the Zirfon® UTP 220 diaphragm, the ultra-thin composite diaphragm demonstrates a reduction in area resistance from 0.19 Ω cm2 to 0.1 Ω cm2, an increase in bubble point pressure from 2.31 bar to 2.46 bar, and a voltage of 1.84 V at 1000 mA cm−2. The incorporation of the PPS mesh resulted in a substantial improvement in tensile strength. The application of an ultra-thin composite diaphragm based on PPS mesh can significantly enhance the efficiency of hydrogen production via alkaline water electrolysis. [Display omitted] • Hot-pressing, phase inversion, and vacuum stirring degassing techniques are adopted. • Sponge pore structure improves the bubble point pressure of composite diaphragms. • Ultra-thin composite diaphragm with low area resistance and cell voltage. • It can work continuously and stably in a high-intensity electrolysis environment. [ABSTRACT FROM AUTHOR]

In this paper, an ultra-thin logo antenna (LGA) operating in multiple frequency bands for Internet of Vehicles (IoVs) applications was proposed. The designed antenna can cover five frequency bands, 0.86–1.01 GHz (16.0%) for LoRa communication, 1.3–1.36 GHz (4.6%) for GPS, 2.32–2.71 GHz (16.3%) for Bluetooth communication, 3.63–3.89 GHz (6.9%) for 5G communication, and 5.27–5.66 GHz (7.1%) for WLAN, as the simulation indicated. The initial antenna started with a modified coplanar waveguide (CPW)-fed circular disk monopole radiator. To create extra current paths and further excite other modes, the disk was hollowed out into the shape of the car logo of the Chinese smart EV brand XPENG composing four rhombic parasitic patches. Next, four triangular parasitic patches were inserted to improve the impedance matching of the band at 5.6 GHz. Finally, four metallic vias were loaded for adjusting resonant points and the return loss reduction. Designed on a flexible substrate, the antenna can easily bend to a certain degree in complex vehicular communication for IoV. The measured results under horizontal and vertical bending showed the LGA can operate in a bending state while maintaining good performance. The proposed LGA addresses the issue of applying one single multi-band antenna to allow vehicles to communicate over several channels, which relieves the need for a sophisticated antenna network. [ABSTRACT FROM AUTHOR]

Abstract Electronic tattoo, capable of imperceivably acquiring bio‐electrical signals from the body, is broadly applied in healthcare and human‐machine interface. Tattoo substrate, the foundation of electronic tattoo, is expected to be mechanically mimetic to skin, adhesive, and breathable, and yet remains highly challenging to achieve. Herein, the study mimics human skin and design a breathable, adhesive, and mechanically skin‐like super tattoo substrate based on an ultra‐thin film (≈2 µm). Similar to skin, super tattoo demonstrates strain‐adaptive stiffening properties with high tear energy (5.4 kJ·m−2) and toughness (1.3 MJ·m−3). Superior to skin, it exhibits high adhesion, ionic conductivity, and permeability. A variety of conductive electrodes can be processed on it, showing the universality toward an ideal platform for electronic tattoo with stable and low contact impedance. Super tattoo‐based electrodes can imperceivably and accurately monitor weak electromyography (EMG) of swallowing on the junction, providing effective guidance for rehabilitation training of dysphagia.

This paper focuses on designing and investigating a new type of metamaterial called an ultra-thin wide-band mu-negative (MNG) metamaterial. The targeted frequency range is 0.1–10 THz. At the resonance frequency of 6.37 THz, the permeability (μ) of the structure is negative, allowing it to function as an MNG metamaterial. Computer Simulation Technology (CST) and High-Frequency Structure Simulator (HFSS) 3D software simulations, examining the scattering and medium parameters of the MNG metamaterial. The findings demonstrate that the proposed MNG metamaterial exhibits resonance peaks in the mu-negative region at 6.37 THz and wide frequency bands of 8.79 THz at −10 dB in the CST simulator. The structure is adaptable based on design parameters. This MNG metamaterial is unique due to its ultra-thin, a form mu-negative wide bandwidth of 3.20 THz, and suitable resonance frequencies. The simulation results from Ansys HFSS software almost align with CST results. The structure, resonating in the THz region with wide bandwidth, shows potential applications in spectroscopy and biomedical engineering. The study encountered difficulties in achieving precise fabrication at the nanoscale and ensuring the reproducibility of metamaterial properties across various samples. Despite these challenges, the proposed metamaterial shows significant advancements in terahertz technology.

Materials with characteristics of omnidirectional reflectionless absorption are of great importance in electromagnetic shielding and anechoic chamber. Recently emerged absorbing surfaces mostly work at a given angle, and absorbers working at a broad frequency band usually suffer from a 3-D structure. Thus, the fabrication of the ultra-thin and omnidirectional reflectionless absorber working at dual-frequency remains a technical challenge. In this work, we demonstrated the absorbing performance of an ultra-thin slab under different incident angles of the electric fields, and an approximate solution was derived to prove the realizability of the dual-frequency and omnidirectional reflectionless absorption. For illustration, a miniaturized dual-frequency anechoic chamber with a 343.8 mm diameter was constructed, and the full-wave simulations validated the results. The proposed design method is simple and robust, which provides a new clue for solving the practicability difficulty faced by existing anechoic chambers and microwave imaging systems. [ABSTRACT FROM AUTHOR]

A polarization-independent meta-material-based absorber with wideband response is presented in this study. The proposed absorber's unit cell consists of a resistance-loaded metallic hexagonal ring and four rectangular metal strips placed inside the hexagonal ring patterned on the upper surface of a dielectric substrate. The absorber exhibits wideband absorption with absorptivity more than 90% in the frequency range 7.14 to 13.68 GHz. The Full-Width Half Maxima (FWHM) of the absorber is 8.8 GHz (5.2–14 GHz). The four-fold symmetrical structure of the absorber confirms polarization-insensitive behaviour. The absorber performance is also validated with fabrication and measurement. There is a fair degree of agreement between simulated and measured results. The novelty of the proposed absorber is having wideband absorption with high packing density due to its hexagonal shape. The metamaterial absorber finds its use in defence-related applications such as radar surveillance, stealth technology, terrestrial communications, and satellite communication. [ABSTRACT FROM AUTHOR]

The influence of nanomechanical tensile behavior on electron transport is especially interesting for ultra-thin SiC nanowires (NWs) with different diameters. Our studies theoretically show that these NWs can hold stable electron transmission in some strain ranges and that stretching can enhance the electron transmission around the Fermi level (EF) at the strains over 0.5 without fracture for a single-atom SiC chain and at the strains not over 0.5 for thicker SiC NWs. For each size of SiC NW, the tensile strain has a tiny effect on the number of device density of states (DDOSs) peaks but can increase the values. Freshly broken SiC NWs also show certain values of DDOSs around EF. The maximum DDOS increases significantly with the diameter, but interestingly, the DDOS at EF shows little difference among the three sizes of devices in the late stage of the stretching. Essentially, high electron transmission is influenced by high DDOSs and delocalized electronic states. Analysis of electron localization functions (ELFs) indicates that appropriate tensile stress can promote continuous electronic distributions to contribute electron transport, while excessively large stretching deformation of SiC NWs would split electronic distributions and consequently hinder the movement of electrons. These results provide strong theoretical support for the use of ultra-thin SiC NWs in nano-sensors for functional and controllable electronic devices. [ABSTRACT FROM AUTHOR]

All‐optical modulation plays a key role in next‐generation optical processing and has attracted enormous attention worldwide. With extraordinary optoelectronic characteristics and friendly integration compatibility with various nanostructures, graphene shows great potential for ultrafast and energy‐efficient all‐optical modulation. Here, high‐efficiency on‐chip all‐optical modulation is experimentally demonstrated based on ultra‐thin silicon/graphene hybrid waveguides, which are complementary‐metal‐oxide‐semiconductor‐compatible and easy to fabricate. Owing to the enhanced light‐graphene interaction enabled by the ultra‐thin silicon photonic platform, the optical nonlinear absorption in graphene is greatly enhanced and a modulation depth of >2 dB is achieved with a saturation threshold of 0.9 pJ per pulse for a 50‐µm‐long modulator. The measured modulation efficiency is as high as 0.052 dB µm−1. Furthermore, the proposed all‐optical modulator has the potential to operate at a bandwidth of hundreds of gigahertz. The present hybrid integration of graphene on ultra‐thin silicon photonic waveguides paves the way toward the applications of on‐chip ultrafast and energy‐efficient all‐optical information processing. [ABSTRACT FROM AUTHOR]

This article deals with the study, design, fabrication, and measurement of a ultra-thin ultra-wideband (UWB) microstrip antenna. As the proposed antenna design is compact, ultra-thin, and optimized in size, it can be used for microwave imaging and wearable applications. Innovation has been used to design the UWB microstrip antenna, which has increased the efficiency and performance of the antenna. This innovation has considered the feed structure, geometry, modifications in the slots, and the use of an ultra-thin dielectric substrate with a thickness of 0.25 mm. The proposed technique is a unique tuning mechanism located under the feed line of the proposed UWB microstrip antenna. The antenna's compact and ultra-thin design is desirable for reducing the complexity of the physical array structure and achieving a degree of body fit. Parametric studies are performed to compare this performance after changes in patch and ground plane length. Finally, the simulated performance parameters were analyzed and compared with the measured results. Due to its small size, new shape, and impressive functions, the proposed antenna is well suited to multifunctional healthcare applications and sports performance monitoring. [ABSTRACT FROM AUTHOR]

The effect of the tensile strain on non-equilibrium electronic properties are studied for the ultra-thin SiC NWs (NWs) with different diameters. Results show that the equilibrium conductance fluctuates with the strain, and the maximum decreases with the increase of the size. Essentially, strong conductance originates from large electron transmission and delocalized electronic states. For I–V characteristics, the tensile strain affects significantly the growth rate and intensity of the current. Under any biases, the strongest current appears in late strain (0.7136) for the single-atom chain, while in the starting strains (e.g. 0.1584, 0.2504) for thicker NWs. The tensile strain would weaken the current of thicker NWs. The mechanical stretching contributes to valuable negative differential resistance (NDR) effect, which appears in middle and late stretching stages such as 5408, 0.7136 and 0.8472 for these three SiC NWs, respectively. Furthermore, NDR effect occurs at more strains and presents multistage features as the diameter of NW increases. The conductance waves with voltage. Such fluctuation deepens and show a more concentrated range with the increased size of NWs. The conductance at closer strains changes with the bias in a relatively close range. From structural evolution, when the NWs are fully extended under tensile strain without structural damage, the necking or the formation of single atom chains, the corresponding conductance and current are stronger, deriving from delocalized electronic states. This work provides an approach to get access to valuable NDR effect and strong backing in promising applications of nano piezoelectric electronics for ultra-thin SiC NWs.

In this paper, a new type of full attachment double‐sided liquid crystal display is designed. The liquid crystal screen and optical films are bonded by OCA called full‐ attachment LCD. The double‐sided display mentioned in this paper uses the same light source on both sides, and the light guide plate is made of glass material or nano material. The double‐sided display designed in this paper is ultra‐thin and the border is extremely narrow. It uses a full attachment optical architecture, higher utilization of light sources, and lower power consumption. Because it does not require a double‐sided backplane design, it is lighter. Its performance has been improved, and its cost has been reduced. [ABSTRACT FROM AUTHOR]

Designing an ultra-thin microwave absorber that can simultaneously realize tunable absorption and broadband optical transparency remains a crucial challenge. In this work, we present a visible–infrared transparent ultra-thin frequency-tunable microwave absorber based on a nanometer-thick patterned vanadium dioxide (VO2) film. The thermally variable sheet resistance of the nanometer-thick VO2 film enables different percentages of equivalent resistance in the equivalent impedance of the patterned VO2 film, which induces the absorbing mode to transform from pure Fabry–Perot (FP) cavity resonant to FP cavity and LC electrical co-resonant. The measured thermally peak absorption frequency modulation range is 15.42–12.99 GHz, while the ultra-thin thickness is only 0.071 of the central wavelength of this range. Moreover, the absorber can achieve high optical transparency from 380 to 6000 nm. Therefore, the proposed absorber has diverse applications in optics and modern intelligent platforms. [ABSTRACT FROM AUTHOR]

The influence of nanomechanical tensile behavior on electron transport is especially interesting for ultra-thin SiC nanowires (NWs) with different diameters. Our studies theoretically show that these NWs can hold stable electron transmission in some strain ranges and that stretching can enhance the electron transmission around the Fermi level (EF) at the strains over 0.5 without fracture for a single-atom SiC chain and at the strains not over 0.5 for thicker SiC NWs. For each size of SiC NW, the tensile strain has a tiny effect on the number of device density of states (DDOSs) peaks but can increase the values. Freshly broken SiC NWs also show certain values of DDOSs around EF. The maximum DDOS increases significantly with the diameter, but interestingly, the DDOS at EF shows little difference among the three sizes of devices in the late stage of the stretching. Essentially, high electron transmission is influenced by high DDOSs and delocalized electronic states. Analysis of electron localization functions (ELFs) indicates that appropriate tensile stress can promote continuous electronic distributions to contribute electron transport, while excessively large stretching deformation of SiC NWs would split electronic distributions and consequently hinder the movement of electrons. These results provide strong theoretical support for the use of ultra-thin SiC NWs in nano-sensors for functional and controllable electronic devices.

In this study, we propose a strategy to construct high-performance ultra-thin optical power converters (OPCs) based on Gires–Tournois resonator configurations operating in high-order modes. Despite reducing the absorber thickness by 5.8 to 8.1 times, the proposed ultra-thin OPCs exhibit the same (comparable) energy absorption characteristic and demonstrate superior electrical performance compared to a thick OPC. It is revealed that such high absorption effects originated from the excitation of optical asymmetric Fabry–Perot-type high-order inference resonance modes and the electrical performance enhancement can be attributed to the reduction of the absorber thickness.

Abstract All‐solid‐state Li metal batteries (ASSLMBs) have been considered the most promising candidates for next‐generation energy storage devices owing to their high‐energy density and safety. However, some obstacles such as thick solid electrolyte (SSEs) and unstable interface between the solid‐state electrolytes (SSEs) and the electrodes have restricted the practical application of ASSLBs. Here, the scalable polyimide (PI) film reinforced asymmetric ultra‐thin (~20 μm) composite solid electrolyte (AU‐CSE) with a ceramic‐rich layer and polymer‐rich layer is fabricated by a both‐side casting method and rolling process. The ceramic‐rich layer not only acts as a “securer” to inhibit the lithium dendrite growth but also redistributes Li‐ions uniform deposition, while the polymer‐rich layer improves the compatibility with cathode materials. As a result, the obtained AU‐CSE demonstrates an ionic conductivity of 1.44 × 10−4 S cm−1 at 35°C. The PI‐reinforced AU‐CSE enables Li/Li symmetric cell stable cycling over 1200 h at 0.2 mA cm−2 and 0.2 mAh cm−2. Li/LiNi0.6Co0.2Mn0.2O2 and Li/LiFePO4 ASSLMBs achieve superior performances at 35°C. This study provides a new way of solving the interface problems between SSEs and electrodes and developing high‐energy‐density ASSLMBs for practical applications.

This article presents the design of wide-band, ultra-thin, and multi-purpose polarization converter utilizing metasurface for C-, X-, and Ku-band applications. Having a topology on a FR-4 substrate with metasurface metallic patterns on the front and an all-metallic surface finish on the back, the unit cell of converter design has symmetry in the x − y plane with unique features of having both linear polarization (LP) and circular polarization (CP) property. While the polarization conversion ratio (PCR) of converter in normal incidence case is more than 90% in three different frequency bands of 6.46–6.78 GHz, 10.52–11.85 GHz, and 16.49–17.37 GHz, it shows linear-to-linear polarization feature and a linear-to-circular polarization feature with left-handed circular polarization (LHCP) for the frequency range between 7.28 and 9.40 GHz and right-handed circular polarization (RHCP) for the frequency range between 13.38 and 15.19 GHz. It is also seen that the converter has a PCR value of around 90% for oblique incidence case with incidence angles up to 45 ° . Extensive simulations have been conducted to prove the performance of suggested converter with the aid of a commercially-available simulation platform, called CST Microwave Studio. The advantages of suggested polarization converter are low-cost, wide-band, ultra-thin, and having both LP and CP conversion in C-, X-, and Ku-bands. [ABSTRACT FROM AUTHOR]

Cr(VI) is of great concern to public health and environmental safety due to its high toxicity. Here, we report a low-cost yet highly efficient method to prepare a novel LDH, ultra-thin layered meixnerite, which performed superiorly in treatment of aqueous Cr(VI) with little secondary pollution being induced. The produced ultra-thin layered meixnerite was composed of nanoparticles with a thickness of around 7 nm, less than 9 times the thickness of a single LDH layer. The XRD patterns of the ultra-thin layered meixnerite, in which the characteristic diffraction peaks of a typical LDH were weakened or even disappeared, confirmed the successful delamination. This special morphology of the ultra-thin layered meixnerite was not only helpful to its full dispersion in the Cr(VI)-bearing solutions but also facilitated the formation of more active sorption sites on its external surface. As a result, the maximum sorption capacity of UTLM for Cr(VI) removal was 480.9 mg g−1, far higher than that of OM (196.9 mg g−1). In addition to electrostatic attraction and anion exchange, the ultra-thin layered meixnerite could also become restacked during removal of aqueous Cr(VI) to generate inner-sphere complexation, finally inducing an enhanced Cr(VI) uptake. Furthermore, XPS analysis characterized the promotion of the break of Al–OH bond with the increase in temperature, and the Cr–O peak increased correspondingly from 29.69% at 25 °C to 48.77% at 85 °C, resulting that the ultra-thin layered meixnerite could remove Cr(VI) more effectively at higher reaction temperatures. Therefore, ultra-thin layered meixnerite is very suitable for future application in treatment of industrial wastewaters with elevated temperatures. [ABSTRACT FROM AUTHOR]

Li metal batteries (LMBs) have attracted widespread attention in recent years because of their high energy densities. But traditional LMBs using liquid electrolyte have potential safety hazards, such as: leakage and flammability. Replacing liquid electrolyte with solid polymer electrolyte (SPE) can not only significantly improve the safety, but also improve the energy density of LMBs. However, till now, there is only limited success in improving the various physical and chemical properties of SPE, especially in thickness, posing great obstacles to further promoting its fundamental and applied studies. In this review, the authors mainly focus on evaluating the merits of ultrathin SPE and summarizing its existing challenges as well as fundamental requirements for designing and manufacturing advanced ultrathin SPE in the future. Meanwhile, the authors outline existing cases related to this field as much as possible and summarize them from the perspective of synthetic chemistry, hoping to provide a comprehensive understanding and serve as a strategic guidance for designing and fabricating high‐performance ultrathin SPE. Challenges and opportunities regarding this burgeoning field are also critically evaluated at the end of this review. [ABSTRACT FROM AUTHOR]

In this paper, a novel ultra‐thin, conformal, triple band metamaterial absorber (MMA) which provides polarization insensitivity along with wide angle stability for C, X, and Ku frequency band applications is presented. The proposed MMA comprises of the modified square ring, circular ring, and two combined identical swastik shaped structures. The calculation reveals that the suggested MMA is capable of providing triple band operations with near unity absorptions of 99.81, 99.77, and 99.68% at 5.20 GHz (C‐band), 9.99 GHz (X‐band), and 14.56 GHz (Ku‐band), respectively. The corresponding full width at half maximum (FWHM) bandwidths are 180 MHz (5.11–5.29 GHz), 320 MHz (9.83–10.15 GHz), and 560 MHz (14.28–14.84 GHz) respectively. The intended unit‐cell is very compact (0.135λ0 × 0.135λ0) and showing ultra‐thin (0.0104λ0) feature. Polarization insensitivity is ensured by means of quadruple symmetry of the proposed unit cell. It is found that the absorptivity greater than 80% is maintained up to 60° for transverse electric (TE) modes and 75° for transverse magnetic (TM) modes. Therefore, it can be stated that it provides excellent wide incidence angle stability. Moreover, adoption of 0.6 mm thick substrate makes it suitable to be employable in defense applications where conformability is a crucial issue. [ABSTRACT FROM AUTHOR]

Aiming at improving the driving safety problems caused by the functional deterioration of the original pavement surface or early diseases when the pavement structure diseases are not prominent and the strength is sufficient, the post blending process is applied to study the ultra-thin cover of skeleton dense SMA-10 warm mix epoxy asphalt. Through a series of tests, the mechanical properties, water stability, crack resistance, sliding durability and interlayer bonding properties were systematically evaluated. The results show that the ultra-thin cover of warm mixed epoxy asphalt has stable and good mechanical properties and serviceability; Basalt fiber has significantly improved its crack resistance. Compared with wood fiber, its bending tensile strain, impact toughness and crack resistance index have increased by 16.7%, 93.9% and 130.4% respectively; Epoxy asphalt mixture has better skid resistance and durability than SBS modified asphalt, which can significantly improve the rapid decline of asphalt pavement functionality; At the same time, epoxy asphalt as binder, its bonding performance is significantly better than matrix asphalt and SBS modified asphalt, and it is suggested that the amount of binder material should be reasonably reduced in high-temperature areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Architecting ultra-thin SiO 2 shell for high magnetic performance of Fe 3 O 4 particles. • Microwave-assisted (MA) synthesis of Fe 3 O 4 @SiO 2 @NH 2 core–shell nanoparticles. • Products with excellent magnetic performance for biomedical applications. • MA had remarkable advantages: ultrafast speed, facile, and ultra-thin SiO 2 shell products. • Fe 3 O 4 @SiO 2 @NH 2 had superparamagnetic characteristic and improved cell compatibility. This research focuses on the architectural design of the silica shell on the Fe 3 O 4 nanoparticle to precisely control and minimize its thickness, with the aim of achieving a final product with optimal saturation magnetization (Ms) for biomedical applications. A rapid and facile microwave-assisted synthesis method was developed for the synthesis of Fe 3 O 4 @SiO 2 and Fe 3 O 4 @SiO 2 @NH 2 core–shell nanoparticles with ultra-thin SiO 2 shells and excellent magnetic performance. The particle size distribution of the Fe 3 O 4 @SiO 2 nanoparticles was in the range of 15–35 nm, with a mean particle size of approximately 21 nm. The mean thickness of the SiO 2 shells on the Fe 3 O 4 cores was found to be 3 nm. FTIR analysis also confirmed the successful silica coating on Fe 3 O 4 nanoparticles and the successful amino-functionalization of silica-coated Fe 3 O 4 nanoparticles. The Ms of Fe 3 O 4 , Fe 3 O 4 @SiO 2 , and Fe 3 O 4 @SiO 2 @NH 2 nanoparticles were found to be 64.4, 59.8, and 52.4 emu/g, respectively. It has been confirmed that the ultra-thin SiO 2 coating has a negligible effect on the magnetic characteristics of the nanoparticles. The developed microwave - assisted synthesis method in this study not only provides an interesting, rapid, and facile synthesis route but also results in a product with a narrow particle size distribution, an ultra-thin SiO 2 shell, favorable magnetic properties, and improved cell compatibility, which may be used in several different applications, particularly biomedical applications. [ABSTRACT FROM AUTHOR]

This research paper examines the execution of ultra-thin solar cells made from chalcopyrite copper indium gallium diselenide (CIGS). The study presents a new CIGS heterojunction solar cell structure, which includes a Cd-free tungsten disulfide (WS 2) buffer layer and poly (3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT: PSS) passivation layer. The performance of the solar cell is raised by a back surface field (BSF). A highly recombining rear surface is kept away from minority carriers by a field created by further strong doping at the back. The structure is Ni/PEDOT:PSS/CIGS/WS 2 /ZnO/Al and has been estimated numerically using the Opto-electrical stimulation of semiconductor layers simulator SCAPS-1D. A high efficiency with a Back surface passivated layer of 25.70 % with V oc of 0.81 V, J sc of 39.33 mA/cm2, and FF of 79.89 % and without passivated layer efficiency of 17.58 % with V oc of 0.73 V, J sc of 32.18 mA/cm2, and FF of 74.78 % is found for the intended CIGS-based solar cell with WS 2 buffer. The interface between CIGS and WS 2 forms a band structure that resembles spikes. This structure is crucial in enhancing the outputs by reducing carrier recombination. The optimal thicknesses for the buffer and CIGS absorber layers are 0.02 μm and 0.2 μm, respectively. These findings help reduce the cost per watt of the solar cell. Fabrication at a mass production scale, minimizing the thickness will have a significant impact on reducing cost. • A novel heterojunction Ni/PEDOT:PSS/CIGS/WS 2 /ZnO/Al solar cell has been designed. • Reducing the thickness of the CIGS absorber layer means a reduction in the cost per watt of the solar cell. • For the first time, an Ultra-thin (200 nm) CIGS solar cell with back surface passivation got an efficiency of 25.70 % with V oc of 0.81 V, J sc of 39.33 mA/cm2, and FF of 79.89 % evaluated. • Improvement of the performance of CIGS solar cells using back surface passivation that minimizes the recombination losses. • Cd-free WS 2 buffer layer with a CIGS absorber reduces carrier recombination and enhances PV outputs. [ABSTRACT FROM AUTHOR]

Abstract Li metal batteries (LMBs) have attracted widespread attention in recent years because of their high energy densities. But traditional LMBs using liquid electrolyte have potential safety hazards, such as: leakage and flammability. Replacing liquid electrolyte with solid polymer electrolyte (SPE) can not only significantly improve the safety, but also improve the energy density of LMBs. However, till now, there is only limited success in improving the various physical and chemical properties of SPE, especially in thickness, posing great obstacles to further promoting its fundamental and applied studies. In this review, the authors mainly focus on evaluating the merits of ultrathin SPE and summarizing its existing challenges as well as fundamental requirements for designing and manufacturing advanced ultrathin SPE in the future. Meanwhile, the authors outline existing cases related to this field as much as possible and summarize them from the perspective of synthetic chemistry, hoping to provide a comprehensive understanding and serve as a strategic guidance for designing and fabricating high‐performance ultrathin SPE. Challenges and opportunities regarding this burgeoning field are also critically evaluated at the end of this review.

In this paper, we present a scheme for achieving broadband efficient beam splitting based on homogeneous ultra-thin metasurfaces, which is composed of an ultrathin dielectric spacer sandwiched between periodic arrays of identical rectangular metal resonators and an optically thick metal film. Based on this scheme, three beam splitters for incident wavelengths in the ultraviolet (UV), visible, and infrared (IR) are designed and investigated numerically. Although these beam splitters exhibit polarization-dependent optical responses, each one still has an operational band in which the conversion efficiency remains above 90 % for any polarization incidence. The operational band is respectively 250–299 nm, 478–574 nm, and 1411–1700 nm for these three metasurface-based beam splitters. Moreover, we propose a dual-band beam splitter and a four-channel beam splitter based on this metasurface with MIM configuration. The operational window of the dual-band beam splitter respectively locates in the visible and infrared regions.

In this study, an innovative fabrication method called rolling-slitting forming, which forms ultra-thin diamond blades, was presented for the first time. Furthermore, the feasibility of the rolling-slitting forming method when applied to silicon carbide wafer dicing blades was investigated; moreover, the cold-pressing blade samples were manufactured through the conventional process under the same sintering conditions to compare and analyze the manufacturing efficiency, organization and performance. The results show that the new method achieves high-precision and low-thickness dicing blades through continuous production without molds—with the thinnest blades being 0.048 mm thick. Furthermore, the rolling-slitting blade has a unique multiporous heat-conductive matrix structure and in-situ generated amorphous pyrolytic carbon, which can reduce the dicing resistance and contribute to a better cutting quality. In addition, the effects of the dicing parameters on SiC were investigated by using indications of spindle current, dicing chipping size and kerf width during the high dicing process. For a dicing depth of 0.2 mm, the ideal performance of dicing SiC with an ultra-thin blade was achieved at a spindle speed of 22,000 rpm and a feed rate of 5 mm/s. This research provides a new idea for the manufacturing of dicing blades, which can satisfy the demand for ultra-narrow dicing streets of high integration of ICs. [ABSTRACT FROM AUTHOR]

CuO is a material with a great promise because of its good stability, environmental protection, low cost, easy development and manufacture, so CuO with various nanostructures has been widely used in different fields such as hydrogen evolution reaction, oxygen evolution reaction, nitrogen reduction reaction, carbon reduction, etc. In this work, the 3D ultra-thin CuO nanosheets were obtained in situ on the copper foam (CuO NS/CF) by a self-designed dielectric barrier discharge microplasma method under ambient temperature and pressure in 10 min. The ultra-thin CuO NS/CF electrode has good electrocatalytic performance for glucose oxidation, with a linear range of 2 μM–6 mM, a sensitivity of 7477 (mA mM−1 cm−2), also has excellent selectivity, reproducibility and stability. This work options for the preparation of ultra-thin CuO nanosheets and their applications in electrochemical sensing. 3D ultra-thin CuO nanosheets were obtained in situ on the copper foam (CuO NS/CF) by a self-designed dielectric barrier discharge (DBD) microplasma method. The CuO NS/CF electrode has excellent sensing performance for glucose with high sensitivity of 7477 μA mM−1 cm−2, low detection limit of 0.53 μM at S/N = 3. [ABSTRACT FROM AUTHOR]

The quest for material‐efficient Cu(In,Ga)Se2 (CIGS) solar cells encourages the development of ultra‐thin absorbers. Their use reduces material consumption and energy usage during production by increasing the throughput. Thereby, both the bill of materials as well as the energy and capital costs are reduced. However, because thin absorbers are prone to increase back contact recombination, back surface passivation schemes are necessary to reach a similar or higher conversion efficiency than for absorbers with conventional thickness. Here, we investigate nanostructured hafnium oxide (HfO2) rear passivation layers for ultra‐thin CIGS solar cells. We fabricate regular arrays of point contacts with 200 nm diameter through HfO2 layers with thicknesses between 7 and 40 nm using electron beam lithography and reactive ion etching. The current–voltage curves of solar cells with a 500 nm thick CIGS absorber layer and the nanostructured passivation layer show improved performance concerning Voc and Jsc compared to non‐passivated reference devices. Furthermore, external quantum efficiency and optical reflection confirm an effective passivation behavior, with an average efficiency increase of up to 1.2% for the cells with the 40 nm thick HfO2 layer. In addition, simulation work shows that even 40 nm thick HfO2 passivation layers have only a minimal effect on the optical properties of ultra‐thin CIGS solar cells, and hence, the photocurrent increase verified experimentally stems from electrical improvements caused by the HfO2 layer passivation effect. We also investigate the impact of ultra‐thin (0.3, 0.6, 1.3, and 2.5 nm) non‐patterned HfO2 passivation layers on the same type of solar cells. However, these results showed no improvement in solar cell performance, despite an increase in the current density with layer thickness. [ABSTRACT FROM AUTHOR]

A broadband ultra‐thin metamaterial absorber (MA) with a multilayer structure is proposed. The G‐type metal layer (GTML) and the square ring metal layer (SRML) are attached to the upper and lower surfaces of the dielectric substrate. Its bandwidth is determined by the high frequency resonant point f퐻0 and low frequency resonant point f퐿0 generated by GTML and SRML. The MA with unit size of 19 mm × 19 mm × 8.6 mm was simulated, manufactured and measured. The results show that the bandwidth of the structure can cover 2.89–8.06 GHz, and the relative bandwidth is 94.43%. Compared with other structures, the total thickness of the element is only 0.083λL, where λ퐿 is the wavelength at 2.89 GHz. [ABSTRACT FROM AUTHOR]

In and Sn are the type of catalysts which do not introduce deep level electrical defects within the bandgap of germanium (Ge). However, Ge nanowires produced using these catalysts usually have a large diameter, a tapered morphology, and mixed crystalline and amorphous phases. In this study, we show that plasma-assisted vaporâ€"liquidâ€"solid (PA-VLS) method can be used to synthesize Ge nanowires. Moreover, at certain parameter domains, the sidewall deposition issues of this synthesis method can be avoided and long, thin tapering-free monocrystalline Ge nanowires can be obtained with In and Sn catalysts. We find two quite different parameter domains where Ge nanowire growth can occur via PA-VLS using In and Sn catalysts: (i) a low temperature-low pressure domain, below ∼235 °C at a GeH4 partial pressure of ∼6 mTorr, where supersaturation in the catalyst occurs thanks to the low solubility of Ge in the catalysts, and (ii) a high temperature-high pressure domain, at ∼400 °C and a GeH4 partial pressure above ∼20 mTorr, where supersaturation occurs thanks to the high GeH4 concentration. While growth at 235 °C results in tapered short wires, operating at 400 °C enables cylindrical nanowire growth. With the increase of growth temperature, the crystalline structure of the nanowires changes from multi-crystalline to mono-crystalline and their growth rate increases from ∼0.3 nm sâˆ'1 to 5 nm sâˆ'1. The cylindrical Ge nanowires grown at 400°C usually have a length of few microns and a radius of around 10 nm, which is well below the Bohr exciton radius in bulk Ge (24.3 nm). To explain the growth mechanism, a detailed growth model based on the key chemical reactions is provided. [ABSTRACT FROM AUTHOR]

Lithium-sulfur (Li-S) batteries present significant potential for next-generation high-energy-density devices. Nevertheless, obstacles such as the polysulfide shuttle and Li-dendrite growth severely impede their commercial production. It is still hard to eliminate gaps between individual particles on separators that serve as potential conduits for polysulfide shuttling. Herein, the synthesis of a nanoscale thickness and defect-free cross-linked polyamide (PA) layer on a polypropylene (PP) separator is presented through in situ polymerization. The PA modification layer can effectively impede the diffusion of polysulfides with a thickness of only 1.5 nm, as evidenced by the results of cyclic voltammetry (CV) and time-of-flight (TOF) testing. Therefore, the Li/Li symmetric battery assembled with the functional separator exhibits an overpotential of merely 12 mV after 1000 h of cycling under test conditions of 1 mA cm -2 -1 mAh cm -2 . Furthermore, the capacity degradation rate of the Li-S battery is only 0.06% per cycle over 450 cycles at 1 C, while the Li-S pouch cell retains 87.63% of its capacity after 50 cycles. This work will significantly advance the preparation and application of molecules in Li-S batteries, and it will also stimulate further research on defect-free modification of separators., (© 2024 Wiley‐VCH GmbH.)

Background : The reconstruction of soft tissue defects of the hand, wrist, and forearm with exposed tendons, joints, bones, and neurovascular bundles represents a great challenge for plastic surgeons. Such defects require early and effective quality coverage to protect the underlying vital structures, preserve hand functions, and allow for early rehabilitation. This study aimed to evaluate the versatility of ultra-thin abdominal flap for the coverage of hand and forearm soft tissue loss with no or minimal morbidity or further debulking procedures. Methods: From January 2013 to April 2019, all patients in whom ultra-thin abdominal flaps were used to resurface soft tissue defects of the hand and forearm were retrospectively reviewed and included in this study. Patient satisfaction was also investigated and categorized into three groups: satisfaction with reconstructed defects, flap donor sites, and the graft donor site. Results: Thirty flaps were used to resurface 30 upper limb defects with minimal complications and good esthetic outcome with no need for further flap debulking. Twenty patients were very satisfied with the defect coverage, nine were satisfied, and one patient was not satisfied. Regarding the flap donor site, 11 patients were very satisfied, 17 were satisfied, while two patients were not satisfied. Conclusions: Soft tissue defects of the upper limb can be reconstructed effectively with the ultra-thin abdominal flap resulting in minor or no complications. This flap gives good results with minimal donor site morbidity if it is well designed and meticulously dissected. Level of evidence: Level IV, Therapeutic study [ABSTRACT FROM AUTHOR]

Cadmium Telluride thin film solar cell is very suitable for building integrated photovoltaics due to its high efficiency and excellent stability. To further reduce the production costs, relieve the scarcity of Tellurium, and apply in building integrated photovoltaics, ultra-thin CdTe photovoltaic technology has been developed. Some study have discussed the research progress of ultra-thin solar cells in terms of silicon and copper indium gallium selenide solar cells, but there are few review papers from the aspect of CdTe solar cells. This review focuses on the ultra-thin CdTe solar cell for the first time and provides a comprehensive and systematic summary. Firstly, the structure of this device is described, and the history of its development is reviewed. Secondly, the advantages and disadvantages of different methods are discussed, and the corresponding solutions are given. Thirdly, the factors limiting device efficiency are analyzed and future directions are suggested. Lastly, the application of ultra-thin device in semi-transparent devices is presented and the challenges are summarized. By reviewing a wide range of materials, we aim to provide valuable insights into the development of ultra-thin cadmium telluride solar cells and to promote its application in building integrated photovoltaics, which is of great importance in reducing carbon emissions to achieve sustainable development. [Display omitted] • This study makes a comprehensive and systematic summary of the development history of ultra-thin CdTe solar cell. • It also analyzes the factors limiting the device efficiency and discusses how to improve the device V oc and J sc. • The future trends and challenges are discussed. • Outlooks the development prospect of ultra-thin semi-transparent CdTe solar cells in BIPV and tandem cell. [ABSTRACT FROM AUTHOR]

[Display omitted] • Direct current electrodeposition of copper foils was intensified by high-gravity. • Thicknesses of equiaxed nanotwinned copper foils were 3.70–4.08 μm. • Copper foils had the tensile strength and elongation of 787 MPa and 21.2 %. • Copper foils had the grain size of 335 nm and the twin lamella thickness of 20 nm. • High efficiency and low energy consumption were obtained in high-gravity fields. In study, a novel strategy was adopted by the integration of microstructure control and electrodeposition process intensification for high-efficiency, low-consumption and convenient electrodeposition of high performance and ≤4.5 μm ultra-thin copper foils for lithium-ion battery (LIB) collectors. The microstructure and the electrodeposition process of copper foils were effectively controlled and enhanced by the synergy of optimized electrolyte and Multi-Concentric Cylindrical Electrodes-Rotating Bed (MCCE-RB) which was used to generate high-gravity fields. Equiaxed nanotwinned copper (nt-Cu) foils possessed ultra-thin thicknesses ranging from 3.70 to 4.08 μm. They exhibited tensile strength and elongation of 787 MPa and 21.2 %, respectively. In contrast to the conventional direct current electrodeposition, electrodeposition and current efficiency were increased by 15.1 % and 27.2 %, respectively, while the energy consumption was decreased by 23.7 % in the high-gravity field. This is beneficial to improve the weight and energy density of LIBs by applying the strategy and technique of high-gravity intensifying. [ABSTRACT FROM AUTHOR]

Flexible pressure sensors have gained significant attention in recent years owing to their versatile applications in health monitoring, human-machine interfaces, and artificial robotics. Geometric microengineering of the active layer, including micropatterned structures, porous layers, and multilayered packed structures has been investigated to improve the sensing performance. However, accompanying challenges such as increased thickness and difficulties in achieving mass production still persist. This work presents a full printed technique for fabricating high-performance piezoresistive pressure sensors. Thermal-treated graphene oxide (TGO) colloid was selected as the printing ink. Combined with an in-situ chemical foaming strategy, structural microengineering of the piezoresistive layer was achieved. The obtained hierarchical protruding micro-domes endow the piezoresistive pressure sensors with a wide sensing range of 550 kPa and ultrathin features (18 μm). In addition, the full-printed manufacturing method enables the batch-producible fabrication of pressure sensors. These sensors can be employed for human motion detection and pressure mapping applications. [Display omitted] • Thermally treated graphene oxide colloid was used as printable inks. • In-situ chemical foaming enable generation of hierarchical protruding micro-domes. • The piezoresistive pressure sensors exhibit a wide sensing range (550 kPa) and ultrathin features (18 μm). • A batch-producible strategy was proposed by full printed technique. [ABSTRACT FROM AUTHOR]

• We numerically show that an ultra-thin Weyl semimetal film can achieve an excellent performance of a high polarization extinction ratio (more than 40 dB) and a low insertion loss (less than 0.07 dB). • Monolayer polarizer shows that the optimum insertion loss is not achieved in the band with the highest PER. An isotropic substrate has little effect on the TM mode, while effectively adjusts the position of TE mode transmission peak. Thus, the proposed sandwich structure can further reduce insertion loss (from 0.06 dB to 0.03 dB) and obtain wider acceptances range of angle (from 49. 5 ∘ to 71 ∘). • Due to the high reflectivity of the two interfaces inside the WSM layer, the incident light is reflected several times in the single-layer structure, forming a structure similar to the Fabry-Perot cavity, which seriously affects the polarizer's performance. To overcome the challenges above, the proposed a gradient Fermi level structure eliminates the interference peak, thus resulting a wider bandwidth (approximately 60 % improvement). This method can be generalized to larger thickness cases. • With the increasing demand for on-chip integrated devices, our work can be helpful for the integration of a range of potential optical applications in optical communication and omnidirectional polarization detectors. Recently, Weyl semimetals have been extensively studied due to their unique optical responses, especially in the mid-infrared region. However, the possibility of developing optical polarizers based on Weyl semimetals remains unexplored. In this paper, under the Voigt geometry, we numerically show that an ultra-thin Weyl semimetal film with thickness L = 100 nm can achieve an impressive polarization extinction ratio (more than 40 dB) with a wide acceptance angle. Further, the proposed sandwich structure can effectively adjust the position of the TE mode transmission peak alone, thus obtaining lower insertion loss (from 0.06 dB to 0.03 dB) and wider acceptance range of angle (from 49. 5 ∘ to 71 ∘). The proposed gradient Fermi level structure eliminates the Fabry-Perot cavity resonance, thus resulting a wider bandwidth (approximately 60 % improvement). Our proposed ultra-thin and wide-angle polarizer may have potential applications in optical communication and omnidirectional polarization detectors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chemical plating and electroplating can be used to prepare ultra-thin copper–aluminum composite foils. • The process is shorter than the traditional aluminum-based copper plating process. • Preparation of transition layers by electroplating tin can form beneficial rivet structures. • The copper–aluminum composite foils have excellent bonding performance and electrical conductive properties. Copper-aluminum composite foils have the advantages of excellent electrical and mechanical properties, lightweight, and low cost. However, overcoming the equipment limitations of physical preparation methods to produce ultra-thin copper–aluminum composite foils with outstanding properties has been a challenge. Herein, smooth-faced, dense, and tightly bonded copper–aluminum composite foils are prepared using a combination of electroless plating and electroplating. This process involves the use of tin and nickel as transition layers, followed by electroplating the copper-clad layer. Ultra-thin copper–aluminum composite foils with a copper layer thickness ranging from 0.5 to 7 μm and a minimum square resistance of 4.6 mΩ can be prepared with a mass of 36.7 %-70 % of that of pure copper foils of the same thickness. These foils are expected to be used in a variety of energy storage components that require extreme lightweight. [ABSTRACT FROM AUTHOR]

We demonstrate the growth of ultra-thin (~5 nm) indium ytterbium oxide (In-Yb-O) thin film using a simple vacuum-free aqueous solution approach for the first time. The influences of Yb addition on the microstructural, chemical, optical, and electrical properties of In2O3 are well investigated. The analyses indicate that Yb dopant could suppress oxygen vacancy defects effectively owing to the lower standard electrode potential, lower electronegativity, and stronger metal-oxide bond strength than that of In. The optimized In-Yb-O thin-film transistors (TFTs) exhibit excellent electrical performance (mobility of 8 cm2/Vs and on/off ratio of ~108) and enhanced stability. The triumph of In-Yb-O TFTs is owing to the high quality In2O3 matrix, the remarkable suppressor of Yb, and the nanometer-thin and atomically smooth nature (RMS: ~0.26 nm) of channel layer. Therefore, the eco-friendly water-induced ultra-thin In-Yb-O channel provides an excellent opportunity for future large-scale and cost-effective electronic applications. [ABSTRACT FROM AUTHOR]

We propose a detailed study of an on-chip optical modulator using a non-conventional silicon-based platform. This platform is based on the optimum design of ultra-thin silicon on insulator waveguide. This platform is characterized by low field confinement inside the core waveguide and high sensitivity to the cladding index. Accordingly, it lends itself to a wide range of applications, such as sensing and optical modulation. By employing this waveguide into the Mach–Zehnder interferometer configuration, an efficient optical modulator is reported using an organic polymer as an active material for the electro-optic effect. An extinction ratio of more than 20 dB is achieved with energy per bit of 13.21 fJ/bit for 0.5 V applied voltage. This studied platform shows promising and adequate performance for modulation applications. It is cheap and easy to fabricate. [ABSTRACT FROM AUTHOR]

Frequency-selective surfaces (FSSs), have various applications in microwave electromagnetics. This paper reports a solution to the current FSS challenges of flexibly, low profile, simple fabrication and polarization control using a novel structure operating across X and Ku frequency bands where a linearly polarized wave is rotated by 90°. The FSSs were fabricated by laser engraving a thin layer of $5\mu \text{m}$ aluminum on a $65~\mu \text{m}$ Mylar substrate with a relative permittivity of 2.7, and separated by a dielectric spacing layer of 0.9 mm polypropylene substrate, with a relative permittivity of 3. The co and cross-polarized reflection and transmission response of the structure was investigated using numerical modeling and was measured experimentally. A parametric study was also conducted focusing on key performance indicators, and specifically the bandwidth of the structure. The novelty of this polarization rotation structure lies in its ultra-thin profile ( $0.034~\lambda _{0}$ ), flexibility and significant transmission bandwidth. The fabricated prototypes experimental results were in good agreement with the simulated results, with a simulated −6 dB bandwidth of 61% and a measured −6dB bandwidth of 60%. Applications include antenna radomes where polarization is particularly important, as well as other polarization filtering applications which require a conformal low profile structure.

An ultra-thin, fracture-resistant and bioresorbable stent may be advantageous for provisional stenting in vessel bifurcations, if catheter passage and side-branch post-dilatation is facilitated to prevent a 'stent jail' by struts obstructing the orifice of a major side branch. We studied a highly radiopaque, slowly bioresorbable zinc alloy stent characterized by a novel design of a radiopaque-marked region of ultra-thin struts in the center of the stent. The stent is characterized by an extended range flexibility and high fracture resistance. Zn-stents and Zn-drug eluting stents (DES) were implanted opposite to rigid Nitinol stents into both femoral artery bifurcations of 21 juvenile pigs, followed for one and three months and studied by angiography and histomorphometry. Results and conclusion: Bare Zn-stents with thinner stent struts showed less neointimal hyperplasia compared to Zn-stents with thicker struts. Neointimal formation was further reduced by 12% in Zn-alloy DES. Both, bare Zn-stents and Zn-DES, can be precisely positioned into the femoral artery bifurcation, allowing easy balloon catheter passage through the very thin strut mesh. Side branch orifices remained open after Zn-stent deployment without stent jailing. No stent fractures or particles emboli occurred after the deployment. A Zn-stent with ultra-thin center struts may be useful for provisional stenting in vessel bifurcations. [ABSTRACT FROM AUTHOR]