Infrared transparent frequency selective surface based on iterative metallic meshes

In this paper, we present an infrared transparent frequency selective surface（ITFSS） based on iterative metallic meshes, which possesses the properties of high transmittance in infrared band and band-pass effect in millimeter wave band. Cross-slot units are designed on the iterative metallic meshes, which is composed of two same square metallic meshes with a misplaced overlap. In the infrared band of 3–5 μm, the ITFSS has an average transmittance of 80% with a Mg F2 substrate. In the millimeter wave band, a transmittance of-0.74 d B at the resonance frequency of 39.4 GHz is obtained. Moreover, theoretical simulations of the ITFSS diffractive characteristics and transmittance response are also investigated in detail. This ITFSS may be an efficient way to achieve the metamaterial millimeter wave/infrared functional film.

Comprehensive evaluation factor of optoelectronic properties for transparent conductive metallic mesh films

Finding the optimal optoelectronic properties(zero-order optical transmittance,shielding effectiveness,and stray light uniformity)of metallic mesh is significant for its application in electromagnetic interference shielding areas.However,there are few relevant studies at present.Based on optoelectronic properties,we propose a comprehensive evaluation factor Q,which is simple in form and can be used to evaluate the mesh with different parameters in a simple and efficient way.The effectivity of Q is verified by comparing the trend of Q values with the evaluation results of the technique for order preference by similarity to ideal solution(TOPSIS).The evaluation factor Q can also be extended to evaluate the optoelectronic properties of different kinds of metallic meshes,which makes it extremely favorable for metallic mesh design and application.

Electrohydrodynamic lithography of metallic mesh for optically transparent flexible and conformal antennas

The optically transparent antenna is becoming a very attractive proposition for various applications, such as wearable devices and vehicle radars. The fabrication of transparent flexible/conformal antennas is a long-lasting interest in academia and industry.However, the preparation of radio-frequency radiators with excellent conductivity and optical transmittance is still quite challenging. Herein, we introduce a facile approach to directly fabricate optically transparent flexible and conformal coplanar waveguide-fed antennas using programmable electrohydrodynamic lithography. Metallic meshes with transmittance above 90%have been successfully created based on the conformal electrohydrodynamic printing of high-viscosity photoresist masks, and the corresponding sheet resistance can be tuned down to ~2 Ω/□. Then, the geometrical structure of the proposed transparent antenna has been systematically optimized because of the basic radio frequency components, including the radiator, feeder line,ground plane, and size of metallic meshes. Optically transparent flexible and conformal antennas are finally obtained, presenting an optical transmittance of 92% and 55%, respectively. The simulated and measured results demonstrate that the transparent antennas with a good optoelectronic performance indeed exhibit a nice electromagnetic behavior. We believe that this newly developed conformal electrohydrodynamic lithography method can be utilized to fabricate a variety of other transparent electronic devices, such as transparent electromagnetic shielding meshes on aircraft canopies, in the future.

Flexible, Transparent and Conductive Metal Mesh Films with Ultra‑High FoM for Stretchable Heating and Electromagnetic Interference Shielding

Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference(EMI)shielding,achieving a flexible EMI shielding film,while maintaining a high transmittance remains a significant challenge.Herein,a flexible,transparent,and conductive copper(Cu)metal mesh film for EMI shielding is fabricated by self-forming crackle template method and electroplating technique.The Cu mesh film shows an ultra-low sheet resistance(0.18Ω□^(-1)),high transmittance(85.8%@550 nm),and ultra-high figure of merit(>13,000).It also has satisfactory stretchability and mechanical stability,with a resistance increases of only 1.3%after 1,000 bending cycles.As a stretchable heater(ε>30%),the saturation temperature of the film can reach over 110°C within 60 s at 1.00 V applied voltage.Moreover,the metal mesh film exhibits outstanding average EMI shielding effectiveness of 40.4 dB in the X-band at the thickness of 2.5μm.As a demonstration,it is used as a transparent window for shielding the wireless communication electromagnetic waves.Therefore,the flexible and transparent conductive Cu mesh film proposed in this work provides a promising candidate for the next-generation EMI shielding applications.

基于机器视觉的大面积触控屏Metal Mesh缺陷检测

由于在大面积触控屏Metal Mesh的生产过程中,曝光机在长时间运行时会出现运行轨迹偏离,造成金属网断线和毛刺等问题.对此,设计了一种用于检测金属网缺陷的机器视觉检测系统,该机器视觉系统能通过工业摄像机采集图像,然后进行图像增强算法祛除环境干扰,Canny边缘检测算法划定图像边界,能快速检测出缺陷和其坐标位置.

Fast ion diffusion alloy layer facilitating 3D mesh substrate for dendrite-free zinc-ion hybrid capacitors

Although aqueous zinc ion hybrid capacitors have advantageous integration of batteries and supercapacitors,they still suffer from the inherent problems of dendrite growth and interfacial side reactions on Zn anodes.Herein,a universal fast zinc-ion diffusion layer on a three-dimensional(3 D)mesh structure model is demonstrated to effectively improve Zn plating/stripping reversibility.The fast ion diffusion alloy layer accelerates the Zn^(2+)migration in an orderly manner to homogenize Zn^(2+)flux and overcomes the defects of the commercial mesh substrate,effectively avoiding dendrite growth and side reactions.Consequently,the proof-of-concept silver-zinc alloy modified stainless steel mesh delivers superb reversibility with the high coulombic efficiency over 99.4%at 4 mA cm^(-2)after 1600 cycles and excellent reliability of over 830 h at 1 mA cm^(-2),Its feasibility is also evidenced in commercial zinc ion hybrid capacitors with activated carbon as the cathode.This work enriches the fundamental comprehension of fast zinc-ion diffusion layer combined with a 3 D substrate on the Zn deposition and opens a universal approach to design advanced host for Zn electrodes in zinc ion hybrid capacitors.

Evaluation of Fracture Resistance for Autopolymerizing Acrylic Resin Materials Reinforced with Glass Fiber Mesh, Metal Mesh and Metal Wire Materials: An in Vitro Study

Statement of problem: Many processes have been applied to improve the fracture resistance of acrylic resin dentures by reinforcing them. The maximum goal of any denture repair is to restore the main strength of the denture and to avoid further fracture. Purpose: This study investigated the ability of self-curing acrylic resin to be strength and deflection of repaired acrylic resin joints reinforced with various reinforcement materials to resist fracture. Material and methods: Transverse strength of polymethyl methacrylate acrylic resin reinforced with glass fiber mesh, metal mesh, and metal wire was evaluated with a 3-point load test on 40 intact specimens (n = 10 for control group) (n = 10 per each reinforcement material group). Fractured joint margins were rounded, a 4-mm gap was placed between them, and then they were repaired with autopolymerizing acrylic resin and retested. Results: Transverse strength for the polymethyl methacrylate acrylic resin samples has showed fracture at the side of sample rather than in the middle area of reinforcement materials and some other samples showed bending statue rather than fracture. Conclusion: Reinforcement with glass fiber mesh, metal mesh, and metal wire produced transverse strength in the side area of resin denture base material rather than in the middle of reinforcement area with bending samples rather than fracture response.

Understanding of the Relationship between the Properties of Cu(In,Ga)Se_(2) Solar Cells and the Structure of Ag Network Electrodes

The relation between the structure of the silver network electrodes and the properties of Cu(In,Ga)Se_(2)(CIGS)solar cells is systemically investigated.The Ag network electrode is deposited onto an Al:ZnO(AZO)thin film,employing a self-forming cracked template.Precise control over the cracked template's structure is achieved through careful adjustment of temperature and humidity.The Ag network electrodes with different coverage areas and network densities are systemically applied to the CIGS solar cells.It is revealed that predominant fill factor(FF)is influenced by the figure of merit of transparent conducting electrodes,rather than sheet resistance,particularly when the coverage area falls within the range of 1.3–5%.Furthermore,a higher network density corresponds to an enhanced FF when the coverage areas of the Ag networks are similar.When utilizing a thinner AZO film,CIGS solar cells with a surface area of 1.0609 cm^(2)exhibit a notable performance improvement,with efficiency increasing from 10.48%to 11.63%.This enhancement is primarily attributed to the increase in FF from 45%to 65%.These findings underscore the considerable potential for reducing the thickness of the transparent conductive oxide(TCO)in CIGS modules with implications for practical applications in photovoltaic technology.

Conversion of CO2 by non-Thermal Inductively-Coupled Plasma Catalysis

CO2 decomposition is a very strongly endothermic reaction where very high temperatures are required to thermally dissociate CO2.Radio frequency inductively-coupled plasma enables to selectively activate and dissociate CO2 at room temperature.Tuning the flow rate and the frequency of the radio frequency inductively-coupled plasma gives high yields of CO under mild conditions.Finally the discovery of a plasma catalytic effect has been demonstrated for CO2 dissociation that shows a significant increase of the CO yield by metallic meshes.The metallic meshes become catalysts under exposure to plasma to activate the recombination reaction of atomic O to yield O2,thereby reducing the reaction to convert CO back to CO2.Inductively-coupled hybrid plasma catalysis allows access to study and to utilize high CO2 conversion in a non-thermal plasma regime.This advance offers opportunities to investigate the possibility to use radio frequency inductively-coupled plasma to store superfluous renewable electricity into high-valuable CO in time where the price of renewable electricity is plunging.

Additive Manufacturing of Large-scale Metal Mesh with Core-shell Composite Structure for Transparent Electromagnetic Shielding/glass Heater

Transparent electromagnetic(EM)shielding glass with a metal mesh has significant potential for application in different fields of EM radiation and anti-EM interference light-transmitting observation windows.In particular,a transparent EM-shielding glass with a large-aspect-ratio metal mesh can effectively alleviate the contradictory problems of shielding effectiveness and light-transmission performance constraints.However,the fabrication of high-aspect-ratio metal meshes on glass substrates has problems such as high cost,complex processes,low efficiency,small area,and easy damage issues,which limit their application in the field of high-performance,transparent EM-shielding glass.Therefore,this paper proposes a composite additive manufacturing process based on electric-field-driven microjet 3D printing and electroplating.By fabricating metal meshes with an Ag-Cu core-shell structure on a glass substrate,EM-shielding glass with high shielding efficiency and light transmission can be manufactured without increasing the aspect ratio of the metal meshes.The prepared Ag-Cu composite metal mesh has excellent optoelectronic properties(period 250𝜇m,line width 10𝜇m,90.1%transmission at 550 nm visible light,square resistance 0.21Ω/sq),efficient electrothermal effect(3 V DC voltage can reach 189°C steady-state temperature),stable EM-shielding effectiveness(average shielding effectiveness 23 dB at X-band),and acceptable mechanical and environmental stability(less than 3%change in square resistance after 150-times adhesion test and less than 6%and 0.6%change in resistance after 72 h in acid and alkali environments,respectively).This method provides a new solution for the mass production of high-performance large-area transparent electric heating/EM-shielding glass.

Design study of an FEL oscillator with a waveguide

We present a design study of a free electron laser （FEL） oscillator for high power THz source experiments on the basis of the Shanghai femtosecond accelerator device. A circular groove guide is used as a new interaction structure. Plane metal meshes are used as upstream and downstream mirrors of the resonator. The general design parameters are presented. We analyzed the spontaneous emission and stimulated emission in the oscillator using these parameters.