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Organic solar cells (OSCs) are considered as a promising new generation of clean energy. Bulk heterojunction (BHJ) structure has been widely employed in the active layer of efficient OSCs. However, precise regulation of morphology in BHJ is still challenging due to the competitive coupling between crystallization and phase separation. Recently, a novel pseudo‐planar heterojunction (PPHJ) structure, prepared through solution sequential deposition, has attracted much attention. It is an easy‐to‐prepare structure in which the phase separation structures, interfaces, and molecular packing can be separately controlled. Employing PPHJ structure, the properties of OSCs, such as power conversion efficiency, stability, transparency, flexibility, and so on, are usually better than its BHJ counterpart. Hence, a comprehensive understanding of the film‐forming process, morphology control, and device performance of PPHJ structure should be considered. In terms of the representative works about PPHJ, this review first introduces the fabrication process of active layers based on PPHJ structure. Second, the widely applied morphology control methods in PPHJ structure are summarized. Then, the influences of PPHJ structure on device performance and other property are reviewed, which largely expand its application. Finally, a brief prospect and development tendency of PPHJ devices are discussed with the consideration of their challenges. [ABSTRACT FROM AUTHOR]

Hefei Advanced Light Facility (HALF) will use a 499.8 MHz superconducting cavity to provide energy for the beam in the storage ring. The fundamental power coupler (FPC) needs to feed 140 kW RF power into the superconducting cavity. In order to meet the requirements of the HALF project, a 499.8 MHz FPC prototype was developed at the National Synchrotron Radiation Laboratory (NSRL). This paper presents the design of the FPC prototype. The fabrication process of the FPC prototype will also be described. The cold test of the FPC prototype room-temperature test stand was carried out. The results show that the cold test performance of the FPC prototype meets the requirements and it can be tested with high power. The high power test of the FPC prototype will be carried out in the future. [ABSTRACT FROM AUTHOR]

A compact, multi-channel ionic liquid-gated graphene field-effect transistor (FET) has been proposed and developed in our work for on-field continuous monitoring of nitrate nitrogen and other nitrogen fertilizers to achieve sustainable and efficient farming practices in agriculture. However, fabricating graphene FETs with easy filling of ionic liquids, minimal graphene defects, and high process yields remains challenging, given the sensitivity of these devices to processing conditions and environmental factors. In this work, two approaches for the fabrication of our graphene FETs were presented, evaluated, and compared for high yields and easy filling of ionic liquids. The process difficulties, major obstacles, and improvements are discussed herein in detail. Both devices, those fabricated using a 3 μm-thick CYTOP® layer for position restriction and volume control of the ionic liquid and those using a ~20 nm-thick photosensitive hydrophobic layer for the same purpose, exhibited typical FET characteristics and were applicable to various application environments. The research findings and experiences presented in this paper will provide important references to related societies for the design, fabrication, and application of liquid-gated graphene FETs. [ABSTRACT FROM AUTHOR]

Seed mucilages are potential sources of natural polysaccharides. They are biodegradable, biocompatible, sustainable, renewable, and safe for human consumption. Due to the desirable physicochemical and functional properties (e.g. gelling, thickening, stabilizing, and emulsifying), seed mucilages have attracted extensive attention from researchers for utilization as a promising material for the development of advanced carrier systems. Seed mucilages have been utilized as natural polymers to improve the properties of various carrier systems (e.g. complex coacervates, beads, nanofibers, and gels) and for the delivery of diverse hydrophilic and lipophilic compounds (e.g. vitamins, essential oils, antioxidants, probiotics, and antimicrobial agents) to achieve enhanced stability, bioavailability, bioactivity of the encapsulated molecules, and improved quality attributes of food products. This review highlights the recent progress in seed mucilage-based carrier systems for food and nutraceutical applications. The main contents include (1) sources, extraction methods, and physicochemical and functional characteristics of seed mucilages, (2) application of seed mucilages for the development of advanced carrier systems, (3) major issues associated with carrier fabrication, and (4) mechanisms of carrier development, latest improvements in carrier formulation, carrier efficiency in the delivery of bioactive agents, and application in food and nutraceuticals. Furthermore, major challenges and future perspectives of seed mucilage-based carriers for a commercial application are discussed. [ABSTRACT FROM AUTHOR]

Copyright of Foundry Technology (1000-8365) is the property of Foundry Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Foundry Technology (1000-8365) is the property of Foundry Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to investigate the influence of micro-nano rough structures on the performance of polytetrafluoroethylene (PTFE) superhydrophobic coatings on cement concrete-based substrates, this study considered the rough structures on the concrete surface and the micro-nano rough structures constructed using micrometer-level diamond, silicon carbide, alumina powder, and nanometer-level hydrophobic silica powder. Contact angle measurements and scanning electron microscopy (SEM) were used to characterize the wettability and micro-structure of PTFE coatings on various rough structures. Additionally, the slip resistance and wear resistance of the coatings were evaluated. The results showed that a two-step fabrication process, involving the construction of micro-nano rough structures followed by PTFE coating modification, achieved the highest superhydrophobic performance. The best results were obtained when micrometer-level and nanometer-level powders were combined, with the performance improving as the dosage increased, with a recommended ratio of 1: 1 and a particle size ratio controlled within the range of 60-120 times. Among different rough structures, diamond showed the best performance, followed by silicon carbide and corundum. After concrete surface treatment with chiseling, all the coatings met the requirements for slip resistance, and after 1000 cycles of reciprocal friction on the test surface using a wet wheel abrasion tester, the superhydrophobicity remained above 85%. This study provides insights into the mechanisms by which micro-nano rough structures affect coating performance and can guide the preparation of practical, high-performance PTFE superhydrophobic coatings. [ABSTRACT FROM AUTHOR]

Ocular prostheses play a crucial role in restoring the form, function, and esthetics of individuals who have undergone trauma or have congenital defects. This case report presents the fabrication and successful application of a ocular prosthesis for a patient who had suffered loss of eye due to trauma in his childhood days. The prosthesis provided the patient with improved facial symmetry, and psychological well-being. The fabrication process, materials used, and clinical outcomes are discussed in detail, along with a review of relevant literature on ocular prostheses.

Negative Poisson's ratio (NPR) structure is a common mechanical meta-material that has great potential in impact protection engineering due to its special indentation resistance. There are many studies on the NPR structures, but there are still few reports on the NPR structures with the parent materials of fiber-reinforced plastics (FRPs). As a type of advanced functional composites, the FRPs have higher specific modulus and specific energy absorption, and have become the most popular lightweight materials. In this review, the characteristics of NPR structures and FRPs were first analyzed and then the existing structure shapes, material types, manufacturing processes and mechanical behaviors were reported and discussed. Finally, the future direction of the mechanical meta-materials with the NPR structure was explored based on the current engineering requirements and preparation technologies. This review is expected to attract more scholars to pay more attention to the NPR structures fabricated by the FRPs. [ABSTRACT FROM AUTHOR]

The eXTP (enhanced X-ray Timing and Polarization) satellite is a prominent X-ray astronomy satellite designed primarily for conducting deep space X-ray astronomical observations. The satellite's scientific payload consists of X-ray focusing mirrors. In order to fulfill the requirements of weight reduction and enhanced effective area, the thickness of mirrors is reduced to the sub-millimeter range and a multi-layer nested structure is employed. Manufacturing mirrors poses a significant challenge to both their quality and efficiency. The present research investigates the optimal replication process for mandrel ultraprecision machining, polishing, coating, electroforming nickel, and demolding. It analyzes the factors contributing to the challenging separation and the inability to release the mirror shells. Additionally, an automatic demolding device is developed, and the X-ray performance of the replication mirrors is verified. The fabrication process flow of the mirrors was initially introduced. To ensure the easy release of the mirror shells from the mandrels, a layer of diamond-like carbon (DLC) was applied as a release layer between the Au and NiP alloy. The adhesion strength of Au-C was found to be significantly lower than that of Au-NiP, as demonstrated by both molecular dynamic simulation and tensile testing. The development of an automatic demolding device with force feedback has been successfully completed. The reduction in the half-power diameter (HPD) of the mirror from 48 inches to 25 inches is an improvement that surpasses the production target. [ABSTRACT FROM AUTHOR]

Metal foam composite is a kind of lightweight composite with low density, high strength, high shielding performance, high damping performance and other characteristics. It has a wide range of application prospects in aerospace, drilling trap floats, artificial bone and other fields, which has attracted people's attention. In this paper, based on the research of the existing literature, the fabrication methods of metal foam composites were introduced, the effect of microstructure on the properties of metal foam composites was analyzed, the progress of mechanical properties, damping properties, shielding properties and heat insulation and their mechanisms of metal foam composites and their applications in relevant fields were reviewed, which provides a theoretical basis for the development of metal foam composites in the future, and the new fabrication technology, modeling research, sandwich structure of metal foam composites and the fabrication of high performance foam hollow sphere composite were also prospected.

Abstract All‐inorganic perovskite solar cells have shown great potential owing to their superior stability against thermal stress and moisture compared to organic–inorganic perovskite solar cells. However, there are some remaining issues in the all‐inorganic perovskite solar cell fabrication process, such as the low solubility of the perovskite precursors and the occurrence of the secondary phases. In this review, we focus on all‐inorganic CsPbBr3 perovskite solar cells and categorize them based on their fabrication process. Various processes and strategies that have been developed to solve the aforementioned issues including the general process of multistep spin coating are thoroughly investigated. Finally, a summary of the various processes for the all‐inorganic CsPbBr3 perovskite solar cells and an outlook for the development of highly efficient all‐inorganic perovskite solar cells are proposed.

ABSTRACTIonic polymer-metal composites (IPMCs) are typical smart materials that are commonly used in bionic applications, including soft robots, bionic flapping aircraft, and bionic fish. However, their low output force seriously limits device performance. Stacking of multiple IPMC actuators to improve the overall performance of soft actuators is a strategy that is used in practical applications. Under the energy dissipation condition in the IPMC stacking structure, if each single IPMC in the structure has high power density, the structure will produce excellent performance with high efficiency that can greatly promote wider application of IPMC actuators. To meet this requirement, a method for fabrication process integration with multiple optimized factors was used to obtain IPMC materials in this paper. Carbon nanotube (CNT) doping, isopropyl alcohol-assisted plating, and hot pressing with a mesoscopic structural mold were selected as typical optimization methods for process integration and were initially investigated separately to determine the optimal process parameters. By combining the best process parameters in an integrated process, the IPMC treated by isopropyl alcohol-assisted plating and CNT doping process (No. AC7) showed excellent actuation performance and high work density (~9.71/12.36 gf, ~14.93/31.89 kJ/m3 under 3/4 VDC). The enhanced performance meets the requirements for practical bionic applications.

Fast development of automotive industry increases demands in terms of fuel efficiency, reduction of weight and increased reliability of constructions. Nowadays major materials for production of pistons are cast iron, Aluminum–Silicon (Al-Si) alloys and some composites. Use of hypereutectic Al-Si alloys is increasing in automobile and aerospace industry. Application of hypereutectic Al-Si alloys with more than 12wt.% of Si is due to their properties like good thermal and electrical conductivity, high strength to weight ratio, good corrosion resistance and others. Higher Si content in the alloy can affect its properties; it increases size of primary Si and hardness but reduces machinability. In order to improve their properties and meet the high requirements of the industry, usually, grain refinement of these alloys is needed. Some of the ways to obtain grain refinement and potentially improve hypereutectic Al-Si alloys' properties are different manufacturing technologies, heat treatments and/or addition of grain refiners like Ni, Mg, Sr, Sn and many others. There is a large amount of manufacturing technologies used for hypereutectic Al-Si alloys, and in this paper will be considered most of them, as well as their influence on microstructure, mechanical and tribological properties of hypereutectic Al-Si alloys and composites. Also, the effect of higher Si content in the hypereutectic Al-Si alloy on its properties will be considered, as well as addition of modificator/refiner or reinforcement. Liquid state processes are usually used for hypereutectic Al-Si alloys, but some newer (semi-solid and solid processes) have emerged that give better microstructure, mechanical and tribological properties, and those are tixocasting, rheocasting and selective laser melting. Based on available investigations tixocasting gives promising results, the only drawback is the price and in the future, investigations should be oriented to finding ways for its reduction. [ABSTRACT FROM AUTHOR]

Graphene and graphene-based materials gifted with high electrical conductivity are potential alternatives in various related fields. However, the electrical conductivity of the macro-graphene materials is much lower than their metal counterparts. Herein, we improved the electrical conductivity of reduced graphene oxide (rGO) based graphene assembled films (GAFs) by applying a series of compressive stress and systematically investigated the relationship between the compressive stress and the electrical conductivity. The result indicates that with increasing applied compressive stress, the sheet resistance increased as well, while the thickness decreased. Under the combined effect of these two competing factors, the number of charge carriers per unit volume increased dramatically, and the conductivity of compressed GAFs (c-GAFs) showed an initial increasing trend as we applied higher pressure and reached a maximum of 5.37 × 105 S/m at the optimal stress of 450 MPa with a subsequent decrease with stress at 550 MPa. Furthermore, the c-GAFs were fabricated into strain sensors and showed better stability and sensitivity compared with GAF-based sensors. This work revealed the mechanism of the tunable conductivity and presented a facile and universal method for improving the electrical conductivity of macro-graphene materials in a controllable manner and proved the potential applications of such materials in flexible electronics like antennas, sensors, and wearable devices. [ABSTRACT FROM AUTHOR]

Ionic polymer-metal composites (IPMCs) are typical smart materials that are commonly used in bionic applications, including soft robots, bionic flapping aircraft, and bionic fish. However, their low output force seriously limits device performance. Stacking of multiple IPMC actuators to improve the overall performance of soft actuators is a strategy that is used in practical applications. Under the energy dissipation condition in the IPMC stacking structure, if each single IPMC in the structure has high power density, the structure will produce excellent performance with high efficiency that can greatly promote wider application of IPMC actuators. To meet this requirement, a method for fabrication process integration with multiple optimized factors was used to obtain IPMC materials in this paper. Carbon nanotube (CNT) doping, isopropyl alcohol-assisted plating, and hot pressing with a mesoscopic structural mold were selected as typical optimization methods for process integration and were initially investigated separately to determine the optimal process parameters. By combining the best process parameters in an integrated process, the IPMC treated by isopropyl alcohol-assisted plating and CNT doping process (No. AC7) showed excellent actuation performance and high work density (~9.71/12.36 gf, ~14.93/31.89 kJ/m3 under 3/4 VDC). The enhanced performance meets the requirements for practical bionic applications. [ABSTRACT FROM AUTHOR]

Herein, we report the oxygen transport phenomenon in the cathode catalyst layer of polymer electrolyte fuel cells. The oxygen transport resistance in the catalyst layer depended on the hot-pressing temperature of the fabrication procedure, suggesting morphological changes in the perfluorosulfonic acid ionomer of the catalyst layers. This work aims to highlight the importance of the manufacturing process in the oxygen transport properties of the catalyst layer.

A new fabrication technique and mixed monomers for a polymer-sustained-alignment liquid-crystal (PSA-LC) cell were proposed in this study. The proposed process for formation of the PSA layer is exposing visible light for polymerization instead of exposing ultraviolet (UV) light. The backlight consisted of light emitting diode (LED) for the LC display (LCD) was used as the source of the visible light, and the mixed monomers were 2,7-dimethacryloyl-oxy-phenanthrene (2,7-DMAPhen) and 4,4'-dimethacryloyl-oxy-benzil (4,4'-DMABzl). Since the monomer 4,4'-DMABzl could generate radicals by a hydrogen abstraction reaction under exposure of the visible light, the PSA layer was formed under the LED-backlight exposure through an intermediary of a polarizer. The fabricated PSA-LC cell showed equal level of voltage holding ratio, residual direct current voltage, and difference in pretilt angle before and after application of an alternate current voltage to the PSA-LC cell fabricated by the UV light exposure. Therefore, we expect that future PSA-LCD would be fabricated without exposure of the UV light. [ABSTRACT FROM AUTHOR]

Over the years, scientists have been focused on the development of microneedle coating process to coat a broad range of therapeutic agents onto the surface of the solid microneedles for effective drug delivery. The precise dose control, content uniformity as well as large-scale production of coated microneedles are still the core issues that have been the interest of researchers in this topic. To this end, a repeatable method that involved a micro-molding process was demonstrated for mass fabrication of coated microneedles with homogeneous and controllable drug loading under mild conditions. In this system, the dissolvable drug carriers with precise dosage were first mounted onto the solid microneedles and then exposed to the high moisture condition to finally obtain the coated microneedle with uniform and precise drug loading. Using the microneedle molds with the volume of 4.71 nL, 8.24 nL, 10.47 nL, and 12.56 nL per cavity, the drug loadings were precisely controlled at 4.8 ng, 6.4 ng, 9.3 ng, and 13.5 ng per needle, with the standard deviation of 0.09, 0.01, 0.07, and 0.53%, respectively. Mechanical property tests showed that the coated microneedles are strong enough for reliable skin insertion, and with in vivo trials in diabetic mice, we further confirmed the similar hypoglycaemic effect of insulin-coated microneedles to subcutaneous injection. Taken together, the micro-molding-based fabrication process has practical merits in the mass production of coated microneedles with homogeneous and controllable drug loading, facilitating the clinical translation of the microneedle technique. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) and its alloys are potential metals for biodegradable implants because of several benefits, including a reduction of stress shielding effect in the implant for orthopedic application and the elimination of the step of a second surgery to remove the implant. On the other hand, unexpected degradation can cause the Mg to collapse, and the implant fails; thus, many studies have been done to control the rate of degradation of Mg alloys. Heterogeneous corrosion of these implants leads to rapid mechanical properties loss, limiting the clinical applications. Adding ceramic reinforcements to the Mg matrix as so-called Mg nanocomposites is one method to enhance the ductility and also mechanical properties of the Mg alloys without a noticeable weight cost. Good corrosion resistance and noticeable mechanical properties of the Mg-based nanocomposites have developed their applications. However, it is difficult to uniformly disperse the ceramic-based nanoparticles as reinforcements in the Mg matrix and attain desired characteristics. As a result, selecting Mg-ceramic composite production methods and reinforcing types to overcome Mg restriction and increase the favorable material features based on their applications is critical. As a result, this review study focus on the different fabrication techniques and reinforcement material types and their influence on Mg-ceramic composites’ mechanical characteristics, in vitro corrosion performance and biocompatibility. The potential applications, and future research ideas of Mg matrix nanocomposite are investigated. The existing successes in this field are discussed, and future investigation areas are identified in order to boost the usage of degradable Mg-based composites.

Micro‐light‐emitting diode (Micro‐LED) is a new type of display device based on the third‐generation semiconductor gallium nitride (GaN) material. Micro‐LED has been applied to micro‐display technology due to its huge development potential. However, the EQE of Micro‐LEDs decreases with the decrease of the sidewall defects, and the passivation process can reduce the sidewall damage and improve the EQE. In this study, the fabrication technology of Micro‐LEDs was summarized and InGaN/GaN multi‐quantum wells (MQWs) Micro‐LEDs from 10 × 10 μm to 200 × 200 μm were fabricated. The improvement effect of different passivation materials on the electrical characteristics of Micro‐LEDs was explored. The results showed that passivation materials could effectively reduce the leakage of the device, reduce the sidewall damage and reduce the ideal factor, among which Si 3N 4 had the most obvious effect. [ABSTRACT FROM AUTHOR]

The eXTP (enhanced X-ray Timing and Polarization) satellite is a prominent X-ray astronomy satellite designed primarily for conducting deep space X-ray astronomical observations. The satellite’s scientific payload consists of X-ray focusing mirrors. In order to fulfill the requirements of weight reduction and enhanced effective area, the thickness of mirrors is reduced to the sub-millimeter range and a multi-layer nested structure is employed. Manufacturing mirrors poses a significant challenge to both their quality and efficiency. The present research investigates the optimal replication process for mandrel ultraprecision machining, polishing, coating, electroforming nickel, and demolding. It analyzes the factors contributing to the challenging separation and the inability to release the mirror shells. Additionally, an automatic demolding device is developed, and the X-ray performance of the replication mirrors is verified. The fabrication process flow of the mirrors was initially introduced. To ensure the easy release of the mirror shells from the mandrels, a layer of diamond-like carbon (DLC) was applied as a release layer between the Au and NiP alloy. The adhesion strength of Au-C was found to be significantly lower than that of Au-NiP, as demonstrated by both molecular dynamic simulation and tensile testing. The development of an automatic demolding device with force feedback has been successfully completed. The reduction in the half-power diameter (HPD) of the mirror from 48 inches to 25 inches is an improvement that surpasses the production target.

Properties such as superior specific strength, being imponderous, and the ability to reprocess are the key features that have drawn attention to magnesium. In the last few years, applications such as automotive, aerospace, and medical applications have been seeking light-weight equipment, and light-weight materials are required for making them. These demands were matched by developing metal matrix composites with magnesium as a base and reinforced with carbon nanotubes (CNTs), grapheme nanoplatelets (GNPs), or ceramic nanoparticles. CNTs have been adopted for developing high-strength metal matrix composites (MMCs) because of their delicately superior thermal conductivity, surface-to-volume ratio, and tensile strength, but lower density. In developing high-performance light-weight magnesium-based MMCs, a small number of CNTs result in refined properties. However, making Mg-based MMCs has specific challenges, such as achieving uniform reinforcement distribution, which directly relates to the processing parameters. The composition of CNT, CNT sizes, their uniform distribution, Mg-CNT interfacial bonding, and their in-between alignment are the characteristic deciding factors of Mg-CNT MMCs. The current review article studies the modern methods to develop Mg-CNT MMCs, specifications of the developed MMCs, and their vital applications in various fields. This review focuses on sifting and summarizing the most relevant studies carried out on the methods to develop Mg-CNT metal matrix composites. The article consists of the approach to subdue the tangled situations in highlighting the Mg-CNT composites as imminent fabrication material that is applicable in aerospace, medical, and automotive fields. [ABSTRACT FROM AUTHOR]

Box girders bridges are widely used in modern highway systems because of their efficiency and attractive appearance. Vehicles loads represent one of the mainly factors that influence the structure reliability of the box girders bridges. Calculation of bridge resistance with different stress due to vehicles loads as close as possible to the real ones constitute the premise of a correct design of the structure. The goal of this study is to realize a description regarding the behavior of box girders bridges analyzed under different vehicles loads conditions. Nowadays the finite element methods (FEM) are highly used because of their capacity to simulate and evaluate the structure efficiency of bridges. By highlighting where the maximum stress values appear we will help the constructor to avoid dangerous sections. Based on this study, we will outline future research directions, aiming to identify and improve the mechanical and strength characteristics of box girders bridges. [ABSTRACT FROM AUTHOR]

Composite materials for vehicle parts require lightweight, high strength and good impact properties. In this study, the optimized manufacturing conditions of epoxy foam (EF) were investigated to improving mechanical performance of carbon fiber reinforced plastic (CFRP)/EF/CFRP sandwich composites for vehicle parts such as impact, flexural property. The optimal curing temperature was found to be 60 °C, by measuring the reaction rate, volume increase rate, density, cell size, glass transition temperature, and specific compressive strength of the EF. In addition, foams after 180 °C thermal aging were observed, and the properties of the EF cured at 60 °C were the most stable under the thermal aging. The performance of the sandwich EF composites was investigated using compressive, flexural strength, lap shear strength, and impact tests. The optimized cell condition of the EF was correlated to improving interfacial adhesion of sandwich composite.

Micro-light-emitting diode (Micro-LED) is a new type of display device based on the third-generation semiconductor gallium nitride (GaN) material. Micro-LED has been applied to micro-display technology due to its huge development potential. However, the EQE of Micro-LEDs decreases with the decrease of the side wall defects, and the passivation process can reduce the sidewall damage and improve the EQE. In this study, the fabrication technology of Micro-LEDs was summarized and InGaN/GaN multi-quantum wells (MQWs) Micro-LEDs from 10 × 10 μm to 200 × 200 μm were fabricated. The improvement effect of different passivation materials on the electrical characteristics of Micro-LEDs was explored. The results showed that passivation materials could effectively reduce the leakage of the device, reduce the sidewall damage and reduce the ideal factor, among which Si3N4 had the most obvious effect. [ABSTRACT FROM AUTHOR]

Sponge aluminum ranged from 10 to 40 PPI was fabricated by investment casting combined with vacuum infiltration, the effects of infiltration temperature, pressure and size of infiltration channel on the infiltration length were systematically studied theoretically and experimentally. The results show that the infiltration temperature difference has little effect on the infiltration length of aluminum foam with the same pore grades. With the increase of infiltration pressure and the decrease of infiltration channel size, the infiltration length increases. By increasing the infiltration pressure to 2 MPa and the infiltration temperature to 700 °C, aluminum sponge with high pore grades can be prepared. Under the same infiltration channel, the porosity of aluminum foam is the same. At this point, the applied infiltration pressure increases and the infiltration length increases. In order to ensure that the infiltration length of sponge aluminum with large pore grades is the same as that of sponge aluminum with small pore grades, the infiltration pressure should be increased. When the size of the infiltration channel, namely the pore grades, remains unchanged, and the infiltration temperature of the metal fluid is increased, the infiltration length will increase. However, it is necessary to consider the gypsum temperature. If the infiltration temperature is too high, the gypsum temperature will be too high, resulting in cracks in the gypsum type and defects in the sponge aluminum. When preparing sponge aluminum with high pore grades, it is necessary to raise the infiltration temperature of the metal liquid in order to obtain the same infiltration length. [ABSTRACT FROM AUTHOR]

This article proposes a methodology and model to optimize the torque of the torsional electromagnetic actuators. Specifically, the analytical expression of the torque is derived, and then optimization of coil’s configuration and the size of the permanent magnet are investigated based on this, which is of great significance to improve the torque and reduce driving current. Additionally, three times of device’s torque performance is achieved when testing the fabricated samples with different sizes of permanent magnets. The experimental results, finite element simulation, and theoretical analysis are in good agreement, illustrating the reliability, practicality, and simplicity of the proposed methodology in a wide range of magnetic actuators. [ABSTRACT FROM AUTHOR]

A novel tunable miniaturized band reject filter employing RF MEMS varactors is reported. Another tunable filter was reported by the authors to work in the Ka-band of frequencies. The present work refers to C-band application making it suitable for satellite and wireless links. Novelty of the work lies in introduction of tunability to such low frequency ranges, compactness in size, CMOS compatibility and more efficient optimized fabrications process. This level of miniaturization has not been achieved by others hitherto. A Coplanar Waveguide (CPW) on a silicon substrate consisting of a central strip conductor with semi-infinite ground planes on both sides is considered where two Complementary Split Ring Resonators (CSRRs) are in series connection on the signal line of CPW. To achieve tunability of the band reject filter, a MEMS bridge capacitor is put on the signal line of the CPW in shunt in either up or down state. The rejection of stop bands are around − 23.80 dB for down state and − 22.90 dB for up state, whereas the centre frequency is 6.5 GHz for down state and 8.1 GHz is for up state simulation and the corresponding measured data are 6.7 GHz (− 35.29 dB) and 8.0 GHz (− 42.90 dB) respectively. The frequency roll off is very sharp because of additional poles. [ABSTRACT FROM AUTHOR]

We designed, fabricated and measured full-color, reflective electrowetting displays (EWDs). The display system is composed of three-layer cyan, magenta and yellow EWD elements fabricated with standard photolithographic techniques. The EWDs were driven successfully by the proposed control system and the measurement results show that the electro-optical performance was improved. The aperture ratio of the EWD element can be tuned from 0 to ∼80% as the applied voltage is changed from 0 to 30 V. The response time and the color gamut were measured to be ∼18 ms and ∼58% NTSC, respectively. This paper makes it possible for large numbers of reflective full-color EWDs to be fabricated directly, with advantages of saving power significantly by 85% and no eye irritation compared with LED displays.

Flexible electronic devices have received great attention in the fields of foldable electronic devices, wearable electronic devices, displays, actuators, synaptic bionics and so on. Among them, high-performance flexible memory for information storage and processing is an important part. Due to its simple structure and non-volatile characteristics, flexible resistive random access memory (RRAM) is the most likely flexible memory to achieve full commercialization. At present, the minimum bending radius of flexible RRAM can reach 2 mm and the maximum ON/OFF ratio (storage window) can reach 108. However, there are some defects in reliability and durability. In the bending process, the cracks are the main cause of device failure. The charge trap sites provided by appropriate doping or the use of amorphous nanostructures can make the conductive filaments of flexible RRAM steadier. Flexible electrodes with high conductivity and flexible dielectric with stable storage properties are the main development directions of flexible RRAM materials in the future.

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Low-Gain Avalanche Diodes are a recently-developed class of silicon sensors. Characterized by an internal moderate gain that enhances the signal amplitude and if built on thin silicon substrates of a few tens of microns, they feature fast signals and exhibit excellent timing performance. Thanks to their fast timing they are planned to be exploited in timing detectors in High-Energy Physics experiments, for example for the upgrades of the ATLAS and CMS detectors at the High Luminosity Large Hadron Collider (HL-LHC) at CERN. However, to achieve a spatially uniform multiplication a large pixel pitch is needed, preventing a fine spatial resolution. To overcome this limitation, the AC-coupled LGAD approach was introduced. In this type of device, metal electrodes are placed over an insulator at a fine pitch, and signals are capacitively induced on these electrodes. The fabrication technology is similar for the two LGAD families, although a fine tuning of a few process parameters needs to be carefully studied. Other R&D efforts towards detectors that can simultaneously provide good time and spatial resolution, based on the LGAD concept, are under way. These efforts aim also to mitigate the loss of performance at high irradiation fluences due to the acceptor removal within the gain layer. In this paper we describe the main points in the fabrication of LGADs and AC-LGADs in a clean-room. We also discuss novel efforts carried on related topics.

Properties such as superior specific strength, being imponderous, and the ability to reprocess are the key features that have drawn attention to magnesium. In the last few years, applications such as automotive, aerospace, and medical applications have been seeking light-weight equipment, and light-weight materials are required for making them. These demands were matched by developing metal matrix composites with magnesium as a base and reinforced with carbon nanotubes (CNTs), grapheme nanoplatelets (GNPs), or ceramic nanoparticles. CNTs have been adopted for developing high-strength metal matrix composites (MMCs) because of their delicately superior thermal conductivity, surface-to-volume ratio, and tensile strength, but lower density. In developing high-performance light-weight magnesium-based MMCs, a small number of CNTs result in refined properties. However, making Mg-based MMCs has specific challenges, such as achieving uniform reinforcement distribution, which directly relates to the processing parameters. The composition of CNT, CNT sizes, their uniform distribution, Mg-CNT interfacial bonding, and their in-between alignment are the characteristic deciding factors of Mg-CNT MMCs. The current review article studies the modern methods to develop Mg-CNT MMCs, specifications of the developed MMCs, and their vital applications in various fields. This review focuses on sifting and summarizing the most relevant studies carried out on the methods to develop Mg-CNT metal matrix composites. The article consists of the approach to subdue the tangled situations in highlighting the Mg-CNT composites as imminent fabrication material that is applicable in aerospace, medical, and automotive fields.

First, we present a fabrication process for electrospun carbon fiber mats with mean fiber diameters between 108 nm and 623 nm. The carbon fiber mats were produced by electrospinning of polyacrylonitrile (PAN) solutions and subsequent carbonization. The fiber mats feature small variations of their properties that are required for parameter studies. Second, we investigate the kinetics of steam and CO2 activation with three different activation temperatures and times. Both activation methods result in a surface area increase depending on activation temperature and time. Detailed analysis of the macroscopic properties burn-off, surface area, and conductivity reveals insights into the microscopic activation kinetics. The different fiber diameters of the carbon fiber mats enable the distinction of surface driven and bulk processes. Our results indicate, that CO2 activation kinetics are mass transport controlled, and that steam activation kinetics are reaction rate controlled. The turbostratic nature of PAN derived carbon and the distinct characteristics of the activation agents could explain the nonlinear behavior of the burn-off and surface area development. [ABSTRACT FROM AUTHOR]