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The seawater desalination and wastewater treatment by the interfacial solar steam generation (ISSG) technique is considered as a green, economical, sustainable, low‐energy‐consumption, and potential fresh water production strategy to solve the water shortage and energy crisis. Recently, efficient biomass‐based ISSGs (BISSGs) have been widely reported due to its efficient photothermal conversion efficiency and good hydrophilic performance. The BISSGs with efficient solar absorption and water transmission performance by design and optimization their various forms and structures and related photothermal properties is also significantly great for its scale application. This review highlights recent advancements in 3D BISSG systems, with a focus on the design and optimization of photothermal conversion materials and substrate materials. Then, the review also discusses the potential of biomass materials in BISSG applications, aiming to provide a theoretical basis for developing cost‐effective, efficient, and sustainable water purification technologies. Finally, the challenges and development prospects of the BISSG system in basic research and practical application will provide theoretical guidance for the further development of this technology. [ABSTRACT FROM AUTHOR]

In this work, we report on a comparative study of the topology, luminescence, and wettability properties of ZnMgO films prepared by a cost-effective spray pyrolysis technology on GaAs substrates with (100), (001), and (111) crystallographic orientations, as well as on Si(100) substrates. Deposition on nanostructured GaAs substrates was also considered. It was found that film growth is not epitaxial or conformal, but rather, it is granular, depending on the nucleating sites for the crystallite growth. The distribution of nucleation sites ensured the preparation of nanostructured films with good uniformity of their topology. The observed difference in columnar growth on Si substrates and pyramidal growth on GaAs ones was explained in terms of the impact of chemical bonding in substrates. The films grown on GaAs substrates with a (001) orientation were found to be made of larger crystallites compared to those deposited on substrates with a (111) orientation. These effects resulted in a difference in roughness of a factor of 1.5, which correlates with the wetting properties of films, with the most hydrophobic surface being found on films deposited on GaAs substrates with a (111) orientation. The prospects for photocatalytic and gas sensor applications of films produced on flat substrates, as well as for plasmonic and other applications of films deposited on nanostructured substrates, are discussed, taking into account the results of the analysis of their photoluminescence properties. [ABSTRACT FROM AUTHOR]

In high‐frequency applications such as 5G‐6G communication, internet of things, automotive radar, and automated driver‐assistance systems, substrate materials excel as insulating layers owing to their superior dielectric properties. However, traditional methods for material development are often laborious and costly. To overcome these limitations, we employed molecular dynamics (MD) simulations to predict the dielectric properties of these materials at frequencies exceeding 107 Hz. Specifically, we selected thermosetting polyphenylene oxide (m‐PPO) as the resin matrix and combined it with three crosslinking agents, respectively: triallyl cyanurate, triallyl isocyanurate, and trimethylallyl isocyanurate. Our overarching goal is to provide comprehensive insights into the development and enhancement of materials critical for high‐frequency electronic devices. We anticipate that this methodology will be widely adopted for the development of advanced substrate materials across various applications, with the objective of effectively screening crosslinkers. Highlights: Developed a simulation method to efficiently explore material scenarios for high‐frequency applications.Studied the dielectric properties of m‐PPO combined with three crosslinking agents at high frequencies.Successfully predicted dielectric properties using MD simulations. [ABSTRACT FROM AUTHOR]

The development of conductive coatings has significant implications for microelectronics and electrochemistry. However, conductive coatings may exhibit different electrochemical properties when prepared on different substrate materials. This research explores the comparative performance of graphene, graphene oxide (GO), and silver nanoparticle (Ag NP) composites as conductive coatings on diverse substrate materials, including polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), and glass. The study employed various preparation methods, such as mixing conductive materials with substrate materials and preparing copolymer composite materials. The conductive coating approach was found to be the most straightforward and convenient, with broader development prospects and fewer restrictive conditions. The results indicate that the distinct surface characteristics of the substrate materials influence the conductive properties of coating materials. Consequently, results show that graphene exhibits the highest conductivity on all three substrates, while GO is more conductive than Ag NPs on PMMA and PDMS but less conductive than Ag NPs on glass. That offers valuable insights into the selection of substrate materials and coating materials for the preparation of conductive materials.

The development of conductive coatings has significant implications for microelectronics and electrochemistry. However, conductive coatings may exhibit different electrochemical properties when prepared on different substrate materials. This research explores the comparative performance of graphene, graphene oxide (GO), and silver nanoparticle (Ag NP) composites as conductive coatings on diverse substrate materials, including polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), and glass. The study employed various preparation methods, such as mixing conductive materials with substrate materials and preparing copolymer composite materials. The conductive coating approach was found to be the most straightforward and convenient, with broader development prospects and fewer restrictive conditions. The results indicate that the distinct surface characteristics of the substrate materials influence the conductive properties of coating materials. Consequently, results show that graphene exhibits the highest conductivity on all three substrates, while GO is more conductive than Ag NPs on PMMA and PDMS but less conductive than Ag NPs on glass. That offers valuable insights into the selection of substrate materials and coating materials for the preparation of conductive materials. [ABSTRACT FROM AUTHOR]

Rapid, sensitive, and accurate detection of adrenoceptor agonists is a significant research topic in the fields of food safety and public health. Immunoassays are among the most widely used methods for detecting adrenoceptor agonists. In recent years, surface-enhanced Raman spectroscopy combined with immunoassay (SERS-IA) has become an effective technique for improving detection sensitivity. This review focuses on the innovation of Raman reporter molecules and substrate materials for the SERS-IA of adrenoceptor agonists. In addition, it also investigates the challenges involved in potentially applying SERS-IA in the detection of adrenoceptor agonists. Overall, this review provides insight into the design and application of SERS-IA for the detection of adrenoceptor agonists, which is critical for animal-derived food safety and public health. [ABSTRACT FROM AUTHOR]

Under the background of peak carbon dioxide emissions and achieving carbon neutrality, clean energy technologies such as water electrolysis, metal–air batteries, and fuel cells have attracted extensive attention due to the advantages of high efficiency, good safety, a simple structure, low cost, and eco-friendliness. However, the key reactions on oxygen catalytic electrodes, the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are kinetically sluggish, which considerably hinders their commercial applications. The traditional oxygen catalytic electrodes with the use of binders have the disadvantages of a cumbersome synthesis process, low controllability, poor uniformity, high cost, and easy carrier catalyst agglomeration, which limit their catalytic performance. Recently, self-supported oxygen catalytic electrodes have attracted extensive attention due to their advantages of high catalytic active sites and a stabilized spatial framework, which can solve the problems faced by traditional oxygen catalytic electrodes and further improve the catalytic performance of the electrode. As the catalyst material carrier, the substrate materials play an important role in the catalytic performance of self-supporting oxygen electrodes. The high interaction forces between the substrate and the catalyst material lead to a single-direction growth orientation and uniform dispersion. Reportedly, the substrate materials for self-supporting oxygen catalytic electrodes have not been fully discussed in comprehensive reviews. Therefore, timely updates in this potential field must be provided. This paper summarizes the research progress and synthesis methods of commonly self-supporting oxygen catalytic electrodes based on different substrate materials, including two- and three-dimensional metal materials and carbon materials. In addition, this paper introduces the outstanding ORR/OER catalytic properties of common self-supporting oxygen catalytic electrodes, which are not only due to the intrinsic catalytic activity of the supported catalytic active materials but also related to the high specific surface area and high electron transfer rate caused by the structure of the self-supported electrode substrate. Finally, the future research and the development trend of self-supporting oxygen catalytic electrodes are addressed from the four aspects of density general function theory, improving electrode energy density, constructing an efficient gas–liquid–solid three-phase interface of an electrode, and establishing a standard evaluation protocol of self-supported oxygen catalytic electrodes. This review should provide new research insights for developing renewable energy storage and conversion systems.

The creation of an electronic component base based on microelectromechanical systems is one of the main directions of the development of modern microelectronics and the basis for the construction of a new generation of radar and communication systems. This is due to the possibility of obtaining fundamentally new electrophysical properties of devices obtained on the basis of microsystem technology. Classification of devices based on microsystem technology includes: switches, varactors, resonators, actuators, filters, etc. Currently, the most widely used radio frequency MEMS switches. This is due, in particular, to the linearity of the transmission characteristics of radio frequency signal switches in a wide frequency range. Radio frequency devices built on the basis of microsystem technology have a good level of isolation (>30 dB) and low insertion losses (<0.5 dB). One of the factors that have a significant impact on the operation of the RF MEMS switch is the choice of materials. The design of the RF MEMS switch consists of the following main elements: substrate, conducting lines, dielectric, beam structures. The choice of materials for each of the listed elements is important, but the substrate material has the most significant effect on the operation of the RF MEMS switch. [ABSTRACT FROM AUTHOR]

Rapid, sensitive, and accurate detection of adrenoceptor agonists is a significant research topic in the fields of food safety and public health. Immunoassays are among the most widely used methods for detecting adrenoceptor agonists. In recent years, surface-enhanced Raman spectroscopy combined with immunoassay (SERS-IA) has become an effective technique for improving detection sensitivity. This review focuses on the innovation of Raman reporter molecules and substrate materials for the SERS-IA of adrenoceptor agonists. In addition, it also investigates the challenges involved in potentially applying SERS-IA in the detection of adrenoceptor agonists. Overall, this review provides insight into the design and application of SERS-IA for the detection of adrenoceptor agonists, which is critical for animal-derived food safety and public health.

The rational design and applications of MXene‐based materials have yielded remarkable progress in flexible sensors, including wearable devices, soft robots, and smart medical equipment. The emerging MXene and substrate materials can be precisely engineered to improve the mechanical properties and sensing sensitivity of the sensors, opening up a wider range of application possibilities for MXene‐based sensors. Therefore, a systematic and comprehensive review summarizing the progress of MXene‐based sensor research based on these backgrounds is necessary. First, we discuss the basic structure of MXene materials and introduce the flexible substrate materials for MXene‐based flexible sensors in detail. Then, we also discuss the different preparation methods of MXene‐based sensors, describe the classifications, and highlight the applications of MXene‐based flexible sensors in various scenarios. Finally, we identify the challenges that need to be overcome to accelerate the development of MXene‐based materials in flexible sensing. This review provides a comprehensive and systematic insight into MXene‐based flexible sensors and it is expected that this review will contribute to the development of higher performance MXene‐based flexible sensors. [ABSTRACT FROM AUTHOR]

The interest for small-size wireless systems has been expanding for quite a few years and this has been made possible by adapting miniaturized antennas with a wide range of performance. Nature-inspired microstrip patch antennas are one of the best solutions to meet the demand for multiband frequencies. A maple-shaped monopole antenna is designed with multiband characteristics and the performance analysis on various substrate materials is carried out. The antenna works over the frequency bands of 3.19 GHz–4 GHz (S-band), 4 GHz–7–17 GHz (C-band), 8.09 GHz–12 GHz (X-band), and 12 GHz–13.81 GHz (Ku-band). The antenna design is simulated using HFSS and obtained the results of return loss, VSWR, gain, and bandwidth. A maximum operating bandwidth of 10.62 GHz and gain of 6.78 dB is achieved with benzocyclobuten as a dielectric substrate and maximum return loss of −57 dB at 8.9 GHz frequency when FR4 epoxy is used. The antenna prototype was made with low-cost FR4 epoxy as a substrate material and tested over the frequency range of 4.27 GHz–14.52 GHz to verify the proposed design. The proposed multiband antenna is suitable for applications in radio altimeters, RADAR, and satellite communications. [ABSTRACT FROM AUTHOR]

The rapid development of the 5G communication technology requires the improvement of the thermal stability and dielectric performance of high-frequency copper clad laminates (CCL). A cyclic olefin copolymer (COC) resin was added to the original 1,2-polybutadienes (PB)/styrene ethylene butylene styrene (SEBS) binary resin system to construct a PB/SEBS/COC ternary polyolefin system with optimized dielectric properties, mechanical properties, and water absorption. Glass fiber cloths (GFCs) and SiO2 were used to fill the resin matrix so to reduce the thermal expansion coefficient (CTE) and enhance the mechanical strength of the composites. It was found that the CTE of polyolefin/GFCs/SiO2 composite laminates decreased with the increase of SiO2 loading at first, which was attributed to the strong interfacial interaction restricting the segmental motion of polymer chains between filler and matrix. It was obvious that the addition of COC and SiO2 had an effect on the porosity, as shown in the SEM graph, which influenced the dielectric loss (Df) of the composites directly. When the weight of SiO2 accounted for 40% of the total mass of the composites, the laminates exhibited the best comprehensive performance. Their CTE and Df were reduced by 63.3% and 22.0%, respectively, and their bending strength increased by 2136.1% compared with that of the substrates without COC and SiO2. These substrates have a great application prospect in the field of hydrocarbon resin-based CCL. [ABSTRACT FROM AUTHOR]

The synthesis of TIO2/SIO2/GSs by using the sol-gel method was done with the mass ratio of Titanium: (GSs) as 1:0.07 and calcined at 450°. The synthesized powder was immobilized onto the sponge substrate by using the dipping method with Polyvinyl alcohol as a binder prepared with the various thickness of the sponge substrate of 0.3, 0.5, 0.8, and 1 cm. The microstructure was investigated utilizing Scanning Electron Microscope (SEM) and phase composition utilizing x-ray Diffraction Spectrometer (XRD). The results of XRD pattern of TIO2/SIO2/GSs show the presence of anatase phase and rutile (83.82%: 16.18%) and the average crystal size is 34.26 nm. The SEM photograph of synthesized powder gave a brief picture of the structure pattern of TIO2/SIO2/GSs follow the layer pattern of GSs while the dipped samples show the tendency of powder powder-coated along the surface of fibers of the sponge. The degradation of methylene blue was analyzed under four kinds of light emission (dark, UV lamp, LED lamp, and solar light). The results show that there are no differences in photocatalytic activity under a UV lamp and solar light. The degradation of MB with the various thickness of the sponge substrate gave different results, on the first 60 min, a sample with thickness 1 cm has the highest degradation of 95% while at 3 h of experiments, all samples gave a similar result. However, the thickness of the sponge substrate in the degradation process has no significant effect occurs to the photocatalytic activity under solar light. [ABSTRACT FROM AUTHOR]

Vacuum-based deposition of optoelectronic thin films has a long-standing history. However, in the field of perovskite-based photovoltaics, these techniques are still not as advanced as their solution-based counterparts. Although high-efficiency vacuum-based perovskite solar cells reaching power conversion efficiencies (PCEs) above 20% are reported, the number of studies on the underlying physical and chemical mechanism of the co-evaporation of lead iodide and methylammonium iodide is low. In this study, the impact of one of the most crucial process parameters in vacuum processes--the substrate material--is studied. It is shown that not only the morphology of the co-evaporated perovskite thin films is significantly influenced by the surface polarity of the substrate material, but also the incorporation of the organic compound into the perovskite framework. Based on these studies, a selection guide for suitable substrate materials for efficient co-evaporated perovskite thin films is derived. This selection guide points out that the organic vacuum-processable hole transport material 2,2�€�,7,7�€�-tet ra(N,N-di-p-tolyl)amino-9,9-spirobifluorene is an ideal candidate for the fabrication of efficient all-evaporated perovskite solar cells, demonstrating PCEs above 19%. Furthermore, building on the insights into the formation of the perovskite thin films on different substrate materials, a basic crystallization model for co-evaporated perovskite thin films is suggested. [ABSTRACT FROM AUTHOR]

A cantilever piezoelectric energy harvester (PEH) is a popular choice to harvest energy for applications with natural or unnatural vibrations. Other than the choice of piezoelectric material, the substrate layer material also plays an important role to increase the energy harvesting in PEH. Earlier researches have emphasized on selecting a few substrate materials than all available in literature. However, we argue that the choice of the substrate material and its mechanical properties depend on the design of the PEH. We establish this fact by designing 20 different PEH models by varying the size of cantilever, substrate layer thickness, and types of the piezoelectric materials. These models are simulated in COMSOL with every known substrate material to select the best substrate material. We also propose a greedy approach to further increase the energy harvesting by optimizing the mechanical properties of the best substrate material. In all models, the best substrate material harvests at least 2 × more energy. The greedy approach increases energy harvesting in almost 50% of the models. Some of the substrate materials with optimized mechanical properties are reported in literature, however, this research opens up a discussion to manufacture new substrate materials to increase energy harvesting in PEH. [ABSTRACT FROM AUTHOR]

The ultra-slippery surface with exceptional slipperiness shows great potential in the fields of liquid food packaging and biomedicine. Although the superhydrophobic surface inspired and created by the "lotus leaf effect" has succeeded in contributing to a high contact angle and widespread applications, its unstable structure, inadequate durability, and reduced hydrophobicity for fluids with high viscosity or poor fluidity are significant drawbacks, which has seriously frustrated the feasible utilization of "lotus leaf effect" induced superhydrophobic surface. To overcome these key bottlenecks, "slippery liquid-infused porous surfaces (SLIPS)" based on the "pitcher plant effect" have emerged at the right moment beyond the superhydrophobic surface, offering excellent performance for fluids with high viscosity, low surface energy, and poor fluidity, as well as low contact angle lag, outstanding self-repairing ability, and high pressure stability. This review first concludes three typical design standards of SLIPS based on the fundamental design principles, followed by summarizing 12 different thermodynamic configurations and 5 kinds of SLIPS failure, which has not yet been well analyzed. Furthermore, the most recent progress on the latest preparation process of SLIPS based on the above principles is also reviewed, and the key effects of substrate structure types, modification characteristics, and lubricants on the functional stability of SLIPS are comprehensively analyzed. The cutting-edge SLIPS prototypes inspired by "pitcher plant effect" principles as well as their promising applications in various great potential fields demonstrating that the green, efficient, stable, easy-to-prepare, and multifunctional materials will play an indispensable role in designing smart and practical SLIPS. [Display omitted] • The design mechanisms of ultra-slippery non-adhesive surface were discussed. • The differences between "lotus leaf effect" and "pitcher plant effect" were demonstrated. • Three design standards of SLIPS based on the fundamental principles were reviewed. • The effects of substrate structure types, modification characteristics, and lubricants of SLIPS are analyzed. • The most recent study progress of SLIPS in high-end applications was reviewed. [ABSTRACT FROM AUTHOR]

Fresh and preserved button mushrooms (Agaricus bisporus) are among the most consumed varieties worldwide. The cultivation is highly optimized and largely based on the use of different compost materials from agricultural wastes as substrates. In this study, we determined the stable carbon (13C) and nitrogen (15N) isotope signatures of the fruiting bodies and used the measured δ values (‰) to obtain indirect information on the medium on which they were grown. The δ13C values (‰) of the investigated fresh and processed button mushrooms from the German market were quite narrow (δ13C values −24.8 ± 0.9 ‰, n = 72), which indicated C3 plant materials as carbon sources. Overall high δ15N values (δ15N values > 5.5 ‰) of the cultivated mushrooms enabled a differentiation to wild growing saprophytes. Furthermore, the broad range of δ15N values (Δ=7 ‰) pointed toward a cultivation on compost materials with varying shares of farmyard manure. While only few samples suggested a cultivation on dominantly plant-based substrates, more than 50% of the investigated button mushrooms were related to high shares of animal manures in the compost mixture. Little variation of δ15N values (‰) in related products collected on subsequent years indicated a high level of standardization of the individual cultivation processes over several years. Analysis of the carbon and nitrogen isotope signatures of cultivated button mushrooms could thus be valuable parameters used for long-term monitoring and controlling purposes. [ABSTRACT FROM AUTHOR]

Integration of electromagnetic (EM) wave absorber with patch antenna array on single substrate provides a very efficient way to improve the radiation pattern of array by reducing mutual coupling effect. The placing of absorber on array assembly may however affect the radiation characteristics due to the heat generated from absorbed power. As the microwave absorber dissipates the inter-element waves in terms of heat via absorption, the ambient temperature of array increases which consequently varies the patch dimensions and dielectric properties of the substrate thus shifting the resonant frequency of array. These effects have been investigated for graphene oxide-based absorber loaded rectangular patch array designed on different substrates such as silicon, gallium arsenide, aluminium oxide and Roger RO3210. On the basis of percentage variation in return loss and effective bandwidth an optimum substrate is proposed which undergoes minimize temperature effect without deteriorating the gain and directivity of the antenna array. The results show that for Graphene oxide-based absorber with Roger RO3210 substrate having high melting temperature of 4236.85 °C, side lobe level of array is reduced from 3.737 dB to 2.551 dB with increased major lobe gain. Due to absorbed power, ambient temperature of array increased from room temperature (27 °C) to 187 °C significantly shifting the resonant frequency from 10.4 GHz to 8.9 GHz. Further the comparison results show that with aluminium oxide substrate the array exhibits minimum temperature sensitivity hence proving to be a better choice for design of microwave absorber loaded antenna array. [ABSTRACT FROM AUTHOR]

In this study, estimation of Ultra-Wideband (UWB) characteristics of microstrip elliptic patch antenna is investigated by means of k-nearest neighborhood algorithm. A total of 16,940 antennas are simulated by changing antenna dimensions and substrate material. Antennas are examined by observing Return Loss and Voltage Standing Wave Ratio (VSWR) characteristics. In the study, classification of antennas in terms of having UWB characteristics results in accuracies higher than 97%. Additionally, Consistency based Feature Selection method is applied to eliminate redundant and irrelevant features. This method yields that substrate material does not affect the UWB characteristics of the antenna. Classification process is repeated for the reduced feature set, reaching to 97.44% accuracy rate. This result is validated by 854 antennas, which are not included in the original antenna set. Antennas are designed for seven different substrate materials keeping all other parameters constant. Computer Simulation Technology Microwave Studio (CST MWS) is used for the design and simulation of the antennas. [ABSTRACT FROM AUTHOR]

Chemical mechanical polishing (CMP) has attracted much attention for high-performance manufacturing and setups, in which the surface roughness Ra is required to be less than 1 nm. In CMP, abrasives play a significant role in polishing quality and efficiency. Herein, we review the synthesis methods of abrasives including sSiO2@mSiO2, PS@CeO2, PS@SiO2 composites and their applications in CMP slurries. Then, the problems and solutions in CMP for soft- and hard-brittle solids and metals are presented in detail, such as cadmium zinc telluride (CdZnTe, soft brittle), silicon carbide (SiC, hard brittle) and copper (Cu, metal). After that, we summarize the molecular dynamics simulations of the CMP processes. Finally, the current problems of CMP and its development perspectives are discussed. [ABSTRACT FROM AUTHOR]

Developing high-efficiency solar photothermal conversion and storage (SPCS) technology is significant in solving the imbalance between the supply and demand of solar energy utilization in time and space. Aiming at the current research status in the field of SPCS, this review thoroughly examines the phase change materials and substrates in SPCS systems. It elucidates the design principles and methods of SPCS integrated composites. Comparatively, it analyzes the parameters of various types of SPCS composites in terms of photothermal conversion, thermal conductivity, energy density, and cycling stability. Additionally, the review discusses the trade-offs between each parameter to achieve the most optimal effect of SPCS. By sorting out the current status of the application of SPCS technology in solar thermal/photovoltaic, aerospace, buildings, textile, and other industries, this analysis clarifies the requirements for various latent heat, phase change temperature, and other properties under different environmental conditions. Through a comprehensive discussion of SPCS technology, this paper accurately captures the development trend of efficiently and comprehensively utilizing solar energy by analyzing existing scientific problems. It identifies bottlenecks in SPCS technology and suggests future development directions that need focused attention. The insights gained from this analysis may provide a theoretical basis for designing strategies, enhancing performance, and promoting the application of SPCS. [Display omitted] • SPCS technology show high efficiency for energy utilization and management. • SPCS can solve the imbalance in the supply and demand of solar energy utilization. • The study of the design principles and methods of SPCS is important. • SPCS system can solve the energy crisis and environmental pollution. • SPCS systems have great potential for practical water treatment in the future. [ABSTRACT FROM AUTHOR]

In this paper, a rectangular microstrip patch antenna (MPA) is designed using different substrate materials for analyzing the performance of the MPA. Alumina (Al2O3), Bakelite, Beryllium oxide (BeO), Gallium Arsenide (GaAs), RT-Duroid and Flame Retardant 4 (FR-4) are the six different substrate used in the design. The size of the rectangular microstrip patch antenna varies according to the dielectric constant of substrate materials used. The operating frequency taken for this analysis is 5.8 GHz. The proposed design provides the study on the performance of rectangular microstrip patch antenna for different substrate materials using the same frequency. This study conveys that which substrate material provides better performance. Moreover, this comparative study conveys that which substrate material provides better performance. The simulation parameters are investigated using HFSS.

Theoretical investigation on horizontally inhomogeneous rectangular microstrip antenna is presented here. The dielectric inhomogeneity is introduced by adding two different substrate materials side by side to increase the degrees of freedom by 2 (arm ratio and relative permittivity of newly added material). TE and TM both modes are used here for theoretical investigations. The transcendental equation is derived here to predict the resonant frequency for different modes. Closed‐form analytical expressions are also given to predict the far‐zone electric fields for different HEM modes. Theoretical results are compared with published results as found in the open literature, data obtained using commercially available numerical three‐dimensional electromagnetic simulator high‐frequency structure simulator, and the authors' own experimental data to show the accuracy of their theory. The additional horizontal dielectric segment gives more flexibility to the antenna designer, leading to wider tuning range over conventional homogeneous RMA. Advantages of this novel antenna structure are also discussed in detail. The authors' theory can be used (or extended) to investigate log‐periodic antenna using RMAs, fractal‐shaped RMAs etc. [ABSTRACT FROM AUTHOR]

Abstract The sun is considered as the most promising abundant renewable energy source that can be exploited to solve many of human beings' challenges such as energy and water scarcity. Solar energy can be utilized in steam and vapor generation processes which has a great importance in many engineering applications such as water desalination, domestic water heating, and power generation. However, dilute solar flux (∼1000 W/m2) cannot supply the absorber with enough power required to overcome water latent heat of vaporization to evaporate water. Optical concentrators such as parabolic trough collector, parabolic dish reflector, and circular Fresnel lens can be used to concentrate the solar radiation to achieve the required power however they suffer from complexity and high cost. Moreover, the efficiency of the conventional solar desalination devices such as solar stills decreases dramatically with increasing bulk water quantity, due to the heat loss to bulk water. Therefore, the need to solar steam generation (SG) devices, that localize heating on a thin layer of water rather than the water bulk, arises. Thin film technology has shown promising progress in SG in which solar energy is utilized to wastewater desalination. The past five years have seen a significant surge in the development of thin film based SG devices. In this review, recently developed thin film-based SG devices are scrutinized with respect to their physical mechanisms, fabrication methods, structure, advantages, and disadvantages. Different types of thin-film materials, including: metal-based nanoparticles, metal oxides, carbon-based materials, polymers, etc.; as well as different substrates materials, including: wood, paper, cotton fabric, carbon fabric, polystyrene foam, and gauze, have been discussed. Moreover, different preparation and synthetization methods of the steam generation devices have been discussed. Suggestions for future research directions are also presented. [ABSTRACT FROM AUTHOR]

• Exploration of thin film sensors: focus on substrates and methods. • Various types of substrates, sensor types, and manufacturing techniques are analyzed. • The choice of substrate directly affects performance and emphasizes sensing modes. • The microstructure of the resistive material has a critical impact on the sensor. Sensors play a pivotal role in modern science and industry. To develop and manufacture high-performance sensors, the selection of appropriate substrate materials, understanding the various types of sensors and their applications, and employing effective fabrication techniques are essential. In this paper, a comprehensive survey is presented on the recent progress in these three core areas. Firstly, the paper analyzes substrate materials for sensors, including metals, semiconductors, and polymers, and explores their characteristics and applications in different types of sensors. Secondly, it provides an overview of the main categories of sensors, including pressure, temperature, and gas sensors, and analyzes their operating principles and applications through several recent case studies. Lastly, fabrication methods for sensors are discussed, and an analysis of how these methods impact the performance and reliability of sensors is presented. This paper aims to offer a preliminary guide for researchers and engineers to make informed decisions in the development and manufacturing of sensors. [ABSTRACT FROM AUTHOR]

The selection of appropriate substrate material acts as a performance regulator for miniaturized graphene patch antenna. The substrate material not only controls the transport properties of graphene but also influences the resonant properties of the graphene patch antenna. The edge fed microstrip line graphene based rectangular patch antenna is designed here for operating in the frequency range 2.67–2.92 THz for wireless applications. The performance is investigated for silicon nitride, aluminum oxide, boron nitride, silica and quartz substrate materials on the basis of return loss, voltage standing wave ratio (VSWR), absorption cross section, bandwidth and radiation efficiency. The comparison of results shows that silicon nitride exhibits overall excellent performance by the virtue of having higher bandwidth and radiation efficiency as compared to other chosen substrate materials.

Existing regulations on the thermal efficiency of building envelope assemblies are based on the steady state thermal properties of substrate materials. Heat transfer mechanisms of passive heat curbing methods such as phase change materials and cool materials, which are dynamic in nature, are currently not being accounted for. The effectiveness of thermo-physical and solar radiation properties of building materials (i.e., solid homogeneous layers without air gap) in reducing the heat gain into a building in a hot climate could be well understood with the equivalent thermal resistance (Req) concept. A simple and easy-to-use mathematical derivation (i.e., to estimate the instantaneous heat flux across an envelope assembly) is proposed in this paper to understand the mechanism of equivalent R-value (i.e., reciprocal of thermal transmittance, U-value) due to solar radiation properties of passive substrate materials. The model is validated against field experiments carried out at two apartment units of a residential building. The Req due to high outer surface solar radiation properties (i.e., by applying a cool coating) is dynamic as it varies with the weather conditions. The effect of a substrate material’s solar radiation and thermo-physical properties on the overall roof thermal performance is investigated using the Req model for four cooling dominated climates around the globe, having different diurnal conditions and sky temperatures. Increasing the outer surface’s solar reflectance (from 10% to 80%) reduces net heat gain through the flat roof during both daytime and nighttime. In contrast, adding only thermal resistance (from 5 mm to 75 mm thick polyurethane) or volumetric heat capacity (by adding 5 mm thick phase change material) to the building envelope brings down heat gain during the day, but not in the night. Thermal insulation is found to be the second effective property, followed by thermal mass irrespective of different diurnal conditions and sky temperatures across the climates.

In this study, a new multi-nozzle trapezoidal microchannel heat sink (MNT-MCHS) was proposed. Five substrate materials, two nanofluids with nanoparticle volume fractions, 0.1% ≤  φ  ≤ 1%, and channel hydraulic diameters, 157.7 µm ≤  D h  ≤ 248.2 µm, were numerically examined in detail. In addition, heat fluxes in the range of 100–1450 W/cm 2 subject to inlet coolant temperature from 15 °C to 75 °C were examined in detail. A locally optimal MNT-MCHS was defined, and a novel equation was proposed for predicting the maximum temperature on the locally optimal MNT-MCHS depending on the heat flux, coolant inlet temperature, and the Reynolds number. It was found that at a Reynolds number of 900, the overall thermal resistance of a MNT-MCHS using copper as a substrate material is improved up to 76% as compared to that using stainless steel 304. The locally optimal MNT-MCHS, using TiO 2 -water nanofluid with φ = 1 % , could dissipate a heat flux up to 1450 W/cm 2 at a Re of 900. A minimum thermal resistance in the present study is improved up to 11.6% and 36.6% in association with those of a multi-nozzle MCHS and a double-layer MCHS, respectively. [ABSTRACT FROM AUTHOR]

Abstract Liquid metals (LM) such as eutectic gallium-indium and gallium-indium-tin are important functional liquid-state metal materials with many unique properties, which have attracted wide attentions especially from soft robot area. Recently the amoeba-like transformations of LM on the graphite surface are discovered, which present a promising future for the design and assemble of self-fueled actuators with dendritically deformable body. It appears that the surface tension of the LM can be significantly reduced when it contacts graphite surface in alkaline solution. Clearly, the specific surface should play a vital role in inducing these intriguing behaviors, which is valuable and inspiring in soft robot design. However, the information regarding varied materials functions underlying these behaviors remains unknown. To explore the generalized effects of surface materials in those intriguing behavior, several materials including glass, graphite, nickel and copper oxides (CuO) were comparatively investigated as substrate surfaces. Important results were obtained that only LM amoeba transformations were observed on graphite and CuO surfaces. In order to identify the proper surface condition for LM transformation, the intrinsic properties of substrate surfaces, such as the surface charge and roughness, as well as the specific interaction with LM like wetting behavior and mutual locomotion etc., were characterized. The integrated results revealed that LM droplet appears more likely to deform on surfaces with higher positive surface charge density, higher roughness and less bubble generation on them. In addition, another surface material, CuO x , is identified to own similar ability to graphite, which is valuable in achieving amoeba-like transformation. Moreover, this study offers a fundamental understanding of the surface properties in realizing LM amoeba transformations, which would shed light on packing and structure design of liquid metal-based soft device within multi-material system. [ABSTRACT FROM AUTHOR]

In this paper, a rectangular microstrip patch antenna (MPA) is designed using different substrate materials for analyzing the performance of the MPA. Alumina (Al2O3,), Bakelite, Beryllium oxide (BeO), Gallium Arsenide (GaAs), RT-Duroid and Flame Retardant 4 (FR-4) are the six different substrate used in the design. The size of the rectangular microstrip patch antenna varies according to the dielectric constant of substrate materials used. The operating frequency taken for this analysis is 5.8 GHz. The proposed design provides the study on the performance of rectangular microstrip patch antenna for different substrate materials using the same frequency. This study conveys that which substrate material provides better performance. Moreover, this comparative study conveys that which substrate material provides better performance. The simulation parameters are investigated using HFSS. [ABSTRACT FROM AUTHOR]

An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10 17 m −3 . By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification. [ABSTRACT FROM AUTHOR]

Cellular phones are used in the vicinity of a human head, which absorbs power from antenna radiation. This investigation analyzes the effects of antenna substrate materials on electromagnetic (EM) absorption in a human head. Antennas are used in analysis with four different dielectric substrate materials, which are Bakelite, FR4 glass epoxy, Rogers R04003, and Taconic TLC. Moreover, two different thicknesses of each substrate are considered in the experimental setup. The EM absorption associated with two types of cell phone antennas is evaluated in the closed vicinity of the human head model. One of them is planar inverted-F antenna (PIFA), which is used as the internal handset antenna and another one is helical antenna, which is used as external handset antenna. This investigation consists of two different operating frequency bands, GSM 900 MHz and DCS 1800 MHz. The EM absorption in the human head is presented using the peak specific absorption rate (SAR) and total absorbed power (TAP) by the user. The finite-difference time-domain (FDTD) method based on Computer Simulation Technology (CST) Microwave studio is utilized in this investigation. The obtained results show that the substrate materials do not effect SAR and TAP values considerably for both antennas, but substrate thickness affects the SAR and TAP values significantly. In addition, the substrate thickness affects the SAR and TAP values significantly in most of the cases Moreover, PIFA produces lower SAR than that of a helical antenna significantly for both GSM and DCS frequency band. [ABSTRACT FROM AUTHOR]

Cells are cultured on platforms made of a variety of materials with selected topographies during studies of cell response and behavior. Understanding the effects of substrates is essential for such applications as developing effective interfaces between body cells and implanted materials and devices. In this study, the effects of substrate surface properties on cell differentiation and alignment on C2C12 myoblasts cultured on conventional or fabricated polymeric cell culture substrates were investigated. Comparisons were made between cells cultured on tissue culture grade polystyrene (TCPS), glass, Permanox, and cured polydimethylsiloxane (PDMS) substrates. Fluorescent immunohistochemistry of cell markers was used to analyse the extent of differentiation. Alignment and guidance of cell growth and spread were studied using patterned platforms. Gratings were made on polystyrene (PS) and PDMS and differentiation was facilitated after 5 days by media exchange. Differences in cell morphology were observed between cells cultured on TCPS and PDMS substrates. Fully differentiated myotubes were observed in highest numbers on TCPS substrates and were non-detectable on PDMS substrates in the time frame of 144 h. Muscle cell alignment and their differentiation followed along the grating patterns on PS and elongated along the pattern length. On the other hand, on PDMS cells formed sheets of tissue and peeled from the substrate. We have revealed the potential for the combinations of surface materials and topography on cell behavior to induce accelerated differentiation and coordinated alignment. The results demonstrate that culture environment can be designed or engineered to modify or regulate muscle cell functions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1638-1645, 2016. [ABSTRACT FROM AUTHOR]

Thin, compliant substrates are increasingly being used for flexible electronics, displays, wearable devices, etc. The dissipation of heat generated in such devices is likely to be an important technological challenge that has not been investigated sufficiently. This paper reports measurement of the out-of-plane thermal conductivity of materials for thin substrates, which is a key material property that governs thermal performance. One-dimensional, steady state thermal conduction is set up in the substrate of interest. Measurements of temperature gradient induced by an imposed heat flux result in the determination of out-of-plane thermal conductivity. Thermal contact resistance between the substrate and experimental setup is also obtained. Measurements are carried out on polyethylene naphthalate (PEN) and polyethylene teraphthalate (PET) substrates of varying thicknesses. Based on the measured thermal conductivity, simulations are carried out to compare the thermal performance of a thin substrate with a traditional substrate. Though flexible electronic devices dissipate very less power, the low thermal conductivity measured here, and the low substrate thickness indicate the critical need for thermal management of such devices. Results reported here indicate an upper limit on power dissipation in a flexible device compared to a traditional device for maintaining similar thermal performance. Measurements reported in this paper may help in the fundamental understanding of thermal transport and thermal management strategies in flexible electronics and displays. [ABSTRACT FROM AUTHOR]

Quality and properties of microwave circuits depend on all the circuit components. One of these components is the substrate. The process of substrate material selection is a decision-making problem that involves multicriteria with objectives that are diverse and conflicting. The aim of this work was to select the most suitable substrate material type to be used in antennas in the microwave frequency range that gives best performance and reliability of the substrate. For this purpose, a model was built to ease the decision-making that includes hierarchical alternatives and criteria. The substrate material type options considered were limited to fiberglass-reinforced epoxy laminates (FR4εr = 4.8), aluminium (III) oxide (aluminaεr = 9.6), gallium arsenide III–V compound (GaAsεr = 12.8) and PTFE composites reinforced with glass microfibers (Duroidεr = 2.2–2.3). To assist in building the model and making decisions, the analytical hierarchy process (AHP) was used. The decision-making process revealed that alumina substrate material type was the most suitable choice for the antennas in the microwave frequency range that yields best performance and reliability. In addition, both the size of the circuit and the loss tangent of the substrates were found to be the most contributing subfactors in the antenna circuit specifications criterion. Experimental assessments were conducted utilising The Expert Choice™ software. The judgments were tested and found to be precise, consistent and justifiable, and the marginal inconsistency values were found to be very narrow. A sensitivity analysis was also presented to demonstrate the confidence in the drawn conclusions. [ABSTRACT FROM AUTHOR]

At millimeter-wave (mm-wave) frequencies, antennas and systems are highly influenced by the electromagnetic characteristics of packaging materials. Accurate knowledge of the complex permittivity of packaging materials is vital for the optimal and robust design of such systems. In this paper, the covered transmission-line method is used to determine the complex permittivity at 60 GHz for several common FR-4 and FR-5 packaging materials. Measurements show that packaging materials must be accurately characterized at high frequencies because their properties can appreciably differ from those at lower frequencies. Moreover, depending on the fabrication process, different thickness samples of the same material can have different permittivity values. The complex permittivity variation versus temperature is also analyzed. We show that, at low frequencies, this variation is negligible, but at mm-wave frequencies, it can represent up to a 5% variation in the relative permittivity and have a severe impact on the loss tangent. The covered transmission-line method is explained in detail and its accuracy and measurable permittivity range are also discussed. [ABSTRACT FROM PUBLISHER]

This paper presents a two-staged, pilot-scale vertical flow engineered wetland-based septage treatment system (VFEWs), which was designed and constructed in Curtin University Sarawak Campus to determine the system efficiency in treatment of septage. The treatment system consists of storage tanks, vertical flow wetlands, and a network of influent and effluent distribution pipes. The first stage of the VFEWs treatment system consists of three vertical flow wetlands placed in parallel to provide pre-treatment to raw septage to reduce solids and organic matters mainly by physical filtration and sedimentation processes. The percolate from the first stage is then further treated in the second stage, with four vertical flow wetlands, each with variation in operational regime and substrate (filter) type. The influences of various system and application-related parameters such as substrate material, presence of plants and plant types, and septage feeding practices (solid loading rate (SLR), batch and intermittent loading, and frequency of daily feeding) on pollutant removal efficiency were studied. Results from the first stage wetlands indicate that the removal of total solids and organic matter (BOD and COD) from the raw septage is promising (> 80%) at both SLR of 100 kg TS/m².yr and 250 kg TS/m².yr, respectively. However, a higher SLR decreased the average NH3-N removal efficiency. The findings on bed clogging assessment during the study period are also presented in this paper. Validation and expansion of these results are carried out with ongoing assessments on the system performance. [ABSTRACT FROM AUTHOR]

Abstract: Numerical investigations are performed to investigate the laminar flow and heat transfer characteristics of trapezoidal MCHS using various types of base nanofluids and various MCHS substrate materials on MCHS performance. This study considered four types of base fluids including water, ethylene glycol (EG), oil, and glycerin with 2% volume fraction of diamond nanoparticle, and four types of MCHS substrate materials including copper, aluminium, steel, and titanium. The three-dimensional steady, laminar flow and heat transfer governing equations are solved using the finite volume method. It is found that the best uniformities in heat transfer coefficient and temperature among the four mixture flows can be obtained using glycerin-base nanofluid followed by oil-base nanofluid, EG-base nanofluid, and water-base nanofluid heat sinks. However, the heat transfer performance of water-base nanofluid can be greatly enhanced in steel made substrate heat sink. [Copyright &y& Elsevier]

Abstract: The temperature-dependent Raman scattering study of SAT0.16:LA0.04:CAT0.8 solid solution crystal are reported. The assignment of vibrational modes in Raman spectra of investigated crystal has been proposed. The Raman spectra provided the evidence for the existence of local ordering of B-site cations in crystal structure. The most of the lattice modes of investigated SAT0.16:LA0.04:CAT0.8 crystal are temperature sensitive. One of these modes (tilt mode at 240cm−1) shows almost 20cm−1 monotonous down-shift of frequency in investigated temperature range. However, A1g mode possessing the largest value of FWHM is the only one blue-shifted mode with the increase temperature. Temperature-dependent Raman investigations indicate a static structural changes in SAT0.16:LA0.04:CAT0.8 crystal caused by local distortions of orthorhombic structure. [Copyright &y& Elsevier]

Abstract: The Fe–N films were synthesized on glass, single crystal Si (100), and NaCl (100) substrate, respectively, by DC magnetron sputtering, and the substrate temperature was optimized to obtain the single-phase γ′-Fe4N magnetic film. The structure and morphology of the samples were characterized using X-ray diffraction (XRD) and atomic force microscopy (AFM). The magnetic properties of the thin films prepared on different substrates were investigated by superconducting quantum interference device (SQUID). The results showed that substrate materials had a significant influence on the magnetic properties of single-phase γ′-Fe4N. The saturation magnetization of films on three different substrate materials had almost the same value, but the coercive force of the films was higher on single-crystal substrates than that of on the amorphous glass substrate. It was also found that the deposition temperature for obtaining single-phase γ′-Fe4N films on NaCl (100) substrate is the lowest. Furthermore, with decreasing of γ′-Fe4N grain size, the coercive force of thin films also decreased. However, the surface roughness had not resulted in much more differences in coercive force for the single-phase γ′-Fe4N thin films with the same thickness. [Copyright &y& Elsevier]

The authors discuss the application of self-assembly techniques for positioning microscopic components onto a substrate in a desired configuration. The basis is a fluidic self-assembly technique in which capillary forces assemble microparts with submicrometer alignment precision. A heat-curable acrylate-based adhesive is used to provide the capillary forces for assembly and is then polymerized in a bath of water at 80°C for 16 h with continuous nitrogen bubbling. The application we describe is self-assembly of flat silicon micromirrors; onto surface-micromachined actuators for use in an adaptive-optics mirror array. Photolithography defines shapes of hydrophobic self-assembled monolayers for self-assembly. Mirrors with fill factors up to 95% were assembled. Mirrors 464 μm in diameter and assembled onto actuators remain flat to within 6 nm rms. This mirror quality would be difficult to attain without the process decoupling afforded by microassembly. The general self-assembly approach described here can be applied to parts ranging in size from the nanometer to the millimeter scale and to a variety of part and substrate materials [ABSTRACT FROM PUBLISHER]

Broadband polarizers functioning in an extremely wide wavelength range from 0.3 to 5 mum were developed based on structural design and numerical simulation. By properly selecting the dual-layer nanowire grids including metal materials, grid periods, grid thicknesses, and substrate materials, broadband polarizers could be developed to realize high optical performance. We proposed a broadband polarizer using aluminum nanowire grids on a magnesium fluoride substrate with 80-nm square grids. The proposed polarizer can reach an extinction ratio from 47 to 70 dB and a transmission efficiency from 38% to 94% in the wide wavelength range. [ABSTRACT FROM PUBLISHER]

Transient thermal analysis of GaN heterojunction field-effect transistors (HFETs) was carried out in this letter, with a hybrid nonlinear finite element method (FEM) employed, i.e., combining the element-by-element FEM with the preconditioned conjugated gradient technique. The maximum temperature of the HFETs, strongly depending on the input power density and the duration time of the pulsed heat source, was captured numerically. The effects of temperature-dependent thermal conductivities of the substrates on the maximum temperature were also examined and compared for different substrate materials, such as sapphire, silicon, and SiC [ABSTRACT FROM PUBLISHER]

Existing regulations on the thermal efficiency of building envelope assemblies are based on the steady state thermal properties of substrate materials. Heat transfer mechanisms of passive heat curbing methods such as phase change materials and cool materials, which are dynamic in nature, are currently not being accounted for. The effectiveness of thermo-physical and solar radiation properties of building materials (i.e., solid homogeneous layers without air gap) in reducing the heat gain into a building in a hot climate could be well understood with the equivalent thermal resistance (Req) concept. A simple and easy-to-use mathematical derivation (i.e., to estimate the instantaneous heat flux across an envelope assembly) is proposed in this paper to understand the mechanism of equivalent R-value (i.e., reciprocal of thermal transmittance, U-value) due to solar radiation properties of passive substrate materials. The model is validated against field experiments carried out at two apartment units of a residential building. The Req due to high outer surface solar radiation properties (i.e., by applying a cool coating) is dynamic as it varies with the weather conditions. The effect of a substrate material's solar radiation and thermo-physical properties on the overall roof thermal performance is investigated using the Req model for four cooling dominated climates around the globe, having different diurnal conditions and sky temperatures. Increasing the outer surface's solar reflectance (from 10% to 80%) reduces net heat gain through the flat roof during both daytime and nighttime. In contrast, adding only thermal resistance (from 5 mm to 75 mm thick polyurethane) or volumetric heat capacity (by adding 5 mm thick phase change material) to the building envelope brings down heat gain during the day, but not in the night. Thermal insulation is found to be the second effective property, followed by thermal mass irrespective of different diurnal conditions and sky temperatures across the climates. [ABSTRACT FROM AUTHOR]