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In this paper, we present a study on a broadband transparent tapered slot antenna. In general, the objective of achieving optical transparency is to enable antennas to seamlessly integrate into windows, offering an aesthetically pleasing and inconspicuous appearance. The aim of our research is to develop antennas that possess the ability to adjust horizontal plane beams across a wide frequency range, from 24 to 28 GHz, for 5G applications. This structure combines three antennas into a single unit, providing an advantage in terms of saving space. Furthermore, this structure offers the possibility of choosing between using a single antenna to obtain a directional beam in the −90°, 0°, or +90° directions (depending on the activated antenna) corresponding to three states, or the combination between two states to obtain another three additional states. The combination of the three states also allows for the acquisition of another state. At this point, the total number of states is 23 − 1. Only three PIN diodes are employed to switch between all states. Additionally, by adjusting the bias values of the PIN diodes, which function as variable resistors, the antenna beamwidth can be adjusted in order to achieve a coverage of 300°, offering more radiation pattern reconfigurability. The proposed method offers several advantages, including simplicity and feasibility in controlling the beamwidth and the beam direction electronically. This structure can be easily integrated into the development of fifth-generation communication systems. [ABSTRACT FROM AUTHOR]

Due to the widespread use of low-power embedded devices in both industrial and consumer applications, research into the use of alternate energy sources has been sparked by the requirement for continuous power. Due to its accessibility and ability to be implanted, RF energy is always taken into consideration among the traditional energy sources that are currently available. There is a significant necessity for efficient RF front-ends, which must provide effective circular polarization (CP) features, effectiveness, feasibility from a design standpoint, and optimal usage of ambient RF signals accessible in the environment. So, for understanding their utilization in RF energy harvesting, a metasurface reflector-inspired CP-printed reconfigurable antenna integrated with a Greinacher voltage divider (GVD) rectifier circuit is reported. It offers broadband CP with fractional bandwidth > 25%, CP gain > 8.35 dBic, and directional radiation with the 3 dB angular beamwidth > 100° in the 3.5/5 GHz bands. With the integration of the rectifier circuit, a theoretical DC output > 4.8 V at 12 dBm is obtained. The acceptable impedance bandwidth, axial ratio bandwidth, antenna gain, antenna efficiency, and directional radiation with a 3 dB angular beamwidth value are studied and subsequently matched with the trade-offs (usage of diodes, complexity of DC biasing circuits, and attainment of polarization reconfigurability) obtained from the state of the art. A comprehensive study of the reconfigurable antennas is reported to highlight the findings as a widespread solution for these limitations in RF energy harvesting application. [ABSTRACT FROM AUTHOR]

The availability of dynamic resource management will be crucial for the deployment of future wireless systems characterized by high data rate services with rigid quality of service demands. Flexible radios appear as the technological answer required to achieve constraint goals under different channel conditions and transmission scenarios. This paper is focused on enhancing another step of flexibility within the resource management by including an efficient handling of computing resources. This concept towards flexible architectures represents a key word for a real successful implementation due to the relationship between the radio applications, which face the scarcity of resources within a heterogeneous environment, and the processing power needed to execute them.

With the rapid development of electromagnetic (EM) wave manipulation technique, programmable metasurfaces with real‐time EM responses (e.g., phase, amplitude) have emerged as a new type of wireless communication transmitter, which has the advantages of simple architecture and low cost. Here, it has been proposed a design strategy of dual‐band wireless communication system based on a spatial‐division‐assisted multi‐level amplitude‐programmable metasurface. The carrier frequency and modulation scheme of each physical channel can be independently designed by changing the external bias voltages and the spatial‐coding sequences applied onto the metasurface. As the proof‐of‐concept, experiments are conducted to prove the feasibility of the system in sub 6G communication band. Two pictures are successfully transmitted via high and low‐frequency channels using binary amplitude‐shift keying and 4 amplitude‐shift keying modulation schemes, respectively. [ABSTRACT FROM AUTHOR]

Emerging 2D nonvolatile Schottky‐barrier‐field‐effect transistors (NSBFETs) are envisaged to build a promising reconfigurable in‐memory architecture to mimic the brain. Herein, a vertically stacked multilayered graphene (MGr)‐molybdenum disufide (MoS2)‐tungsten ditelluride (WTe2) NSBFET is reported. The semimetal WTe2 with the charge‐trapping effect enables the simultaneous integration of the electrode and the self‐gating function. The effective Schottky barrier height offset ΔΦB is programed from ΔΦB‐p = 132.6 meV to ΔΦB‐n = 109.4 meV, inducing the reversed built‐in electric field to make the NSBFET, so as to provide one with a multifunctional platform to integrate the nonvolatility and the reconfigurable self‐powered photo response. The reversible open‐circuit voltages of NSBFET synapse are programmed from −0.1 to 0.25 V and the self‐powered responsivity with reversed signs is tuned from 290 to −50 mA W−1, which enables the representation of a signed weight in a single device to enrich multiple optical sensing and computing capabilities. [ABSTRACT FROM AUTHOR]

The counterfeiting of products is a serious concern for any nation with the increasing activity of counterfeit markets. Anticounterfeiting tags demand low‐cost, unclonable, facile, and ultrafast manufacturing processes. In this study, a laser‐induced carbonization (LIC) technique is employed to produce discrete sizes of LIC spots distributed randomly in an array fashion, as a tag, preferably on a laser wavelength‐sensitive polyimide (PI) film. This technique enables the intrinsic creation of LIC spots in PI without any foreign functional materials, thus avoiding the need for external material. Owing to laser technology, based on the input design and laser processing parameters, the reconfigurable desired output tags can be accomplished in a very short time. Different forms of LIC spots in an optical image are grouped and sorted into three‐level bits based on their sizes and brightness for digitalization. The unique LIC‐based tags can be applied to the flexible printed circuit board industry to address counterfeiting. [ABSTRACT FROM AUTHOR]

Photonic logic gates have important applications in fast data processing and optical communication. This study aims to design a series of ultra-compact non-volatile and reprogrammable photonic logic gates based on the Sb2Se3 phase-change material. A direct binary search algorithm was adopted for the design, and four types of photonic logic gates (OR, NOT, AND, and XOR) are created using silicon-on-insulator technology. The proposed structures had very small sizes of 2.4 μm × 2.4 μm. Three-dimensional finite-difference time-domain simulation results show that, in the C-band near 1550 nm, the OR, NOT, AND, and XOR gates exhibit good logical contrast of 7.64, 6.1, 3.3, and 18.92 dB, respectively. This series of photonic logic gates can be applied in optoelectronic fusion chip solutions and 6G communication systems. [ABSTRACT FROM AUTHOR]

The current uncertain and volatile business context is challenging firms worldwide, leading to the need to be responsive at a competitive cost. This trend is so substantial that it even affects industries traditionally competing in rather stable contexts, such as the process industry. Although the process industry includes multiple sectors with different technologies and processes, these share several aspects that make the industry as a whole distinctive to the discrete manufacturing industry. Based on a literature review, this study identifies and describes trends leading the process industry to the need for responsiveness, corresponding solutions to accommodate the need, and related challenges hindering the industrialization and diffusion of solutions in this industry. This study shows that trends, such as the uncertainty and volatility of market requirements, are challenging the process industry to develop reconfigurability solutions across multiple production levels. The development of reconfigurability solutions is hindered by modularity, integrability, co-ordination and collaboration challenges. [ABSTRACT FROM AUTHOR]

Thermoset polymers cross‐linked by dynamic covalent bonds are recyclable and reconfigurable based on solid‐state plasticity, resulting in less waste and environmental pollution. However, most thermoset polymers previously reported show thermal‐responsive solid‐state plasticity, depending much on external conditions and not allowing for local shape modulation. Herein, the isocyanate modified carbon nanotubes (CNTs‐NCO) are introduced into the polythiourethane (PCTU) network with multiple dynamic covalent bonds by in situ polymerization to prepare the composite with thermal/light dual‐responsive solid‐state plasticity, reconfigurability, and recyclability. The introduction of CNTs‐NCO simultaneously strengthens and toughens the PCTU composite. Moreover, based on the photothermal properties and light‐responsive solid‐state plasticity, the PCTU/CNTs composite or bilayer sample can achieve complex permanent shape by locally precise shape regulation without affecting other parts. This work provides a simple and reliable method for preparing high‐performance polymer composite with light‐responsive solid‐state plasticity, which may be applied in the fields of sensing and flexible electronics. [ABSTRACT FROM AUTHOR]

Assembly systems require to be designed considering flexibility from a holistic perspective to produce the variety of current and future product generations. Reactive ad hoc changes after realizing both the product and assembly system designs require considerable effort and may even be impossible. A systematic collaborative approach that concurrently considers the early phases of product and assembly system development appears to be essential for working with long-term changes. To this end, a greater understanding of the working procedures and design activities concerning flexibility is required. In this paper, this is investigated based on a theoretical framework and a multiple case study at a world-leading manufacturer of heavy-duty vehicles. As a result, a developed early phase design process to enable long-term flexibility in assembly systems is presented. The theoretical implications provided and the findings are also relevant to those involved in the design process of flexible assembly systems. [ABSTRACT FROM AUTHOR]

Flexible and reconfigurable (FAR) electronics are in high demand for emerging applications, including wearable, bioelectronics, and internet of things. Highly scalable antenna arrays or periodic surfaces are required for high directivity or electromagnetic wave path control, particularly for 5G millimeter‐wave (mm‐wave) due to high path losses. Conventional lumped tuning components have limitations related to scalable FAR electronics and hence highly scalable and flexible vanadium dioxides (VO2) switch array is proposed for mm‐wave applications. A frequency reconfigurable mm‐wave absorber is designed by screen printing the VO2 switch array to demonstrate the proposed approach feasibility for large scale electronics, achieving high scalability, tunability, and flexibility because the 40 µm thick VO2 switch array satisfies radio frequency switch requirement. Flexibility and repeatability are tested up to 2000 bending cycles with 25 mm bending radius, and tunability and scalability are demonstrated with 300 ON/OFF ratio, and 98% product yield for 400 switches printed on 144 × 144 mm2 polyethylene terephthalate substrates. Absorption frequency is switchable from 14 to 28 GHz at 150 mm bend radius while retaining better than 90% absorptivity as a frequency reconfigurable mm‐wave absorber. Therefore, the proposed VO2 switch array would be suitable for scalable 5G and 6G FAR electronics. [ABSTRACT FROM AUTHOR]

Digital twins are representations of real-world systems in the digital world, relying on physical system data to optimise, manipulate, detect, and interact. The requirements of digital twins diverge depending on the application in focus. The complexity ranges from simple to highly complex use cases, which increases setup time and reduces maintainability. Therefore, different representations and views of the digital twin are necessary, e.g., file type conversions or abstractions of geometry. Standards that try to solve these problems are ISO 21597, by providing containerisation and linkage of data, and ITU-T Y.3090 and ISO 23247, by providing frameworks to support the creation process of digital twins. Based on these standards, this paper aims to enable a holistic view of digital twin applications in flexible manufacturing cells to reduce the implementation effort when the system is installed or changes. We identify a digital twin's most relevant features, parameters, and assets. This feature set is categorised regarding the frequency of changes. The main observable manufacturing elements are machine tools, robots, peripheral devices like autonomous mobile robots (AMRs), manufacturing utilities like tools, and processes. Various information systems depend on or interact with these manufacturing cells, e.g., CAM, PLM, MES, tool management, fleet control, and cell control. While applying the framework of ISO 23247 to a flexible manufacturing cell, we found that life cycle changes are only considered for products and not for the digital twin itself. Therefore we try to emphasise life cycle changes by linking the manufacturing cell to a life cycle meta-layer, simplifying the design, deployment, and updates of digital twin applications. This linkage remains valid through changes, reducing application maintenance effort by allowing re-instantiation of the applications. Therefore, a multidimensional representation of the physical layer can address rapidly changing real-time data to hardly changing life cycle information. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic revealed weaknesses in the global supply chain management. With stock-outs, transportation problems and the bullwhip effect caused by ever-changing demand, it is necessary for decision-makers to review their supply chain configuration. The latter must adapt to new market changes and respond quickly and cost-effectively to customer requirements. In fact, the selection criteria of the most reconfigurable configuration, i.e., the configuration that adapts its structure and its functions to the new market changes, must respond to this problem. The aim of this paper is to conduct a literature review of the criteria and methods for configuration selection in reconfigurable manufacturing systems and reconfigurable supply chains. This study allows to define a roadmap for the configuration selection in reconfigurable supply chains based on the most efficient reconfigurability criteria. We provide new trends to consider in this selection problem. This paper allows managers to choose the most appropriate criteria to implement a reconfigurable supply chain. [ABSTRACT FROM AUTHOR]

The effectiveness of Recurrent Neural Networks (RNNs) for tasks such as Automatic Speech Recognition has fostered interest in RNN inference acceleration. Due to the recurrent nature and data dependencies of RNN computations, priorwork has designed customized architectures specifically tailored to the computation pattern of RNN, getting high computation efficiency for certain chosen model sizes. However, given that the dimensionality of RNNs varies a lot for different tasks, it is crucial to generalize this efficiency to diverse configurations. In this work, we identify adaptiveness as a key feature that is missing from today's RNN accelerators. In particular, we first show the problem of low resource utilization and low adaptiveness for the state-of-the-art RNN implementations on GPU, FPGA, and ASIC architectures. To solve these issues, we propose an intelligent tiled-based dispatching mechanism for increasing the adaptiveness of RNN computation, in order to efficiently handle the data dependencies. To do so, we propose Sharp as a hardware accelerator, which pipelines RNN computation using an effective scheduling scheme to hide most of the dependent serialization. Furthermore, Sharp employs dynamic reconfigurable architecture to adapt to the model's characteristics. Sharp achieves 2×, 2.8×, and 82× speedups on average, considering different RNN models and resource budgets, compared to the state-of-the-art ASIC, FPGA, and GPU implementations, respectively. Furthermore, we provide significant energy reduction with respect to the previous solutions, due to the low power dissipation of Sharp (321 GFLOPS/Watt). [ABSTRACT FROM AUTHOR]

Origami tubes can be crafted from thin-walled sheets, enabling the creation of a wide range of unique three-dimensional structures that are foldable and reconfigurable through ingenious mechanical designs. In this paper, a novel reconfigurable origami tube with flat-foldable motion and tunable load-bearing capacity is proposed. The unit cell of the origami tube is designed by combining two origami triangle elements with varying creases. The geometry of the triangle elements are analyzed, leading to different types of unit cells with various kinematical configurations. The proposed origami structures possess both the ability to fold flat and the flexibility to tune its load-bearing capacity while maintaining consistent external dimensions. In such a manner, the origami structure can be assembled in series or parallel and show a wide range of a programmable mechanical properties Both experimental tests and finite element models are built to investigate the deformation behaviors of the unit cells. It is found that the proposed Miura-ori structures can achieve high load bearing capability (up to 2300 times of its self weight). It is anticipated that our design and analysis approach could facilitate the development of man-made reconfigurable metamaterials. [Display omitted] • A reconfigurable origami tube is created with varied inner crease designs. • The origami pattern enables different configurations with consistent external size. • The tube supports loads up to 2300 times its weight while remaining flat-foldable. • Tubes can be assembled in series or parallel for customizable load-bearing capacity. [ABSTRACT FROM AUTHOR]

The ability to adapt to changes in products, processes and technologies is a key competitive factor. Changeable manufacturing paradigms have emerged to address this need, but the industrial implementation remains challenging. In this paper, a participatory design methodology for changeable manufacturing systems is proposed, including requirements specification, selection of appropriate manufacturing paradigm and suitable physical and logical enablers. The methodology supports companies in determining the potential for and mechanisms of transitioning towards changeable manufacturing systems, based on knowledge of products, production, technologies and facilities. The developed methodology is applicable to both new and existing manufacturing systems. It is demonstrated in two industrial cases which highlight its applicability and differences in the appropriate recommended manufacturing systems transition towards changeability as a result of differences in manufacturing characteristics, change requirements and enablers. [ABSTRACT FROM AUTHOR]

The fourth industrial revolution requires higher capabilities of changeability and reconfigurability (C-R) of the future factories (FoF), as well as a higher focus on business models that are based on total-cost-of-ownership (TCO) paradigm. Up to date, there are little scientific contributions to deploy C-R into TCO models, as well as to systematic plan and design manufacturing resources such as to facilitate FoF ecosystem. In order to address this issue, this paper introduces research results that show how to deploy C-R, connectivity, smartness and TCO requirements into the technical solutions of manufacturing resources of FoF. Contributions emerging from this research include an index to measure C-R capability of manufacturing resources, a model to assess economic feasibility of a FoF over its lifecycle, as well as a methodology and related tools to design smart connected manufacturing resources with embedded features to facilitate changeability and reconfigurability in a FoF. Theoretical contributions are explained through a case study of a fast reconfigurable robotic manufacturing cell. Preliminary results demonstrate that it is possible to rapid design smart connected manufacturing resources and integrate them into FoF architectures that support convertibility, integrability, modifiability, adaptability, serviceability, scalability, integration of resources from various producers, service clustering and cloud-based services. [ABSTRACT FROM AUTHOR]

The development of the next generation of wireless systems is bringing renewed attention to the physical layer of the communication link. Indeed, the new low-latency requirements cannot be satisfied relying only upon the extreme virtualization of the hardware functions. Moreover, conventional wireless systems with fixed characteristics and functionalities are not appropriate to modern electromagnetic environments, which undergo continuous and fast variations. Embedded smartness is a required feature for widening the range of the possible electromagnetic responses to support advanced and novel functionalities. In this paper, we show how the combination of 2D metastructures with conventional antennas and reflectors enables an unprecedented electromagnetic behavior, which is at the basis of new properties, capabilities, and applications. In particular, we propose an emerging design approach based on the shifting of the reconfigurability, adaptivity, sensing, and power management of a wireless system at the physical level, thanks to the use of properly designed 2D metastructures to be coupled with standard antennas and reflectors.

In this work, several representative terahertz (THz) graphene holographic impedance surface antenna are presented. Different to the conventional impedance surface antenna that manipulates the surface impedance via varying the patch size in each unit cell, the surface impedance of the proposed antenna in this paper is readily controlled by applying a tunable DC biasing to each graphene patch cell, the physics behind which is that the conductivity of the graphene is a function of imposed voltage. Thus, the graphene patches of the proposed antenna have same size as well as equal spacing, which makes the modeling process more convenient and efficient. Furthermore, for the purpose of beam scanning, the proposed THz graphene holographic antenna can be easily reached by varying the DC supply. Besides, due to the excellent mechanical property of graphene, the proposed THz graphene holographic antenna can be designed conformal to required platforms. To validate and verify the proposed above ideas, a linear polarized with beam scanning capability, a circularized and a conformal THz graphene holographic antenna are designed and simulated via full-wave commercial software HFSS, the simulation results are in good agreements with the design theories.

In Cable-Suspended Parallel Robots (CSPRs), reconfigurability, i.e., the possibility of modifying the position of the cable connection points on the base frame, is particularly interesting to investigate, since it paves the way for future industrial and service applications of CSPRs, where the base frame can also be replaced by mobile agents. This report focuses on fully actuated Translational Reconfigurable CSPRs (TR-CSPRs), i.e., reconfigurable CSPRs with a point mass end-effector driven by three cables. The objective of the work is twofold. First, it is shown that the Wrench Exertion Capability (WEC) performance index can be exploited to identify the configurations of the cable connection points optimizing a task-related performance in a single point or throughout the workspace, and hence to implement a workspace analysis. Then, by referring to the case of a TR-CSPR with a single reconfigurable connection point and in quasi-static working condition, an analytical approach is provided to reconfigure the robot while executing a task to avoid one of the paramount problems of cable robots: cable slackness. Brought together, the two contributions allow defining a reconfiguration strategy for TR-CSPRs. The strategy is presented by applying it to a numerical example of a TR-CSPR used for lifting and moving a load along a prescribed path: the use of the WEC allows analyzing the workspace and predicting if robot reconfigurability makes it possible to pass quasi-statically along all the points of a given path; then reconfigurability is exploited to avoid cable slackness along the path.

Modular self-configurable robot (MSR) systems have been investigated for decades, and their applications have been widely explored to meet emerging automation needs in various applications, such as space exploration, manufacturing, defense, medical industry, entertainment, and services. This paper aims to gain a deep understanding of up-to-date research and development on MSR through a thorough survey of market demands and published works on design methodologies, system integration, advanced controls, and new applications. In particular, the limitations of existing mobile MSR are discussed from the reconfigurability perspective of mechanical structures.

Soft robots are of increasing interest as they can cope with challenges that are poorly addressed by conventional rigid‐body robots (e.g., limited flexibility). However, due to their flexible nature, the soft robots can be particularly prone to exploit modular designs for enhancing their reconfigurability, that is, a concept which, to date, has not been explored. Therefore, this paper presents a design of soft building blocks that can be disassembled and reconfigured to build different modular configurations of soft robots such as robotic fingers and continuum robots. First, a numerical model is developed for the constitutive building block allowing to understand their behavior versus design parameters, then a shape optimization algorithm is developed to permit the construction of different types of soft robots based on these soft building blocks. To validate the approach, 2D and 3D case studies of bio‐inspired designs are demonstrated: first, soft fingers are introduced as a case study for grasping complex and delicate objects. Second, an elephant trunk is used for grasping a flower. Third, a walking legged robot. These case studies prove that the proposed modular building approach makes it easier to build and reconfigure different types of soft robots with multiple complex shapes. [ABSTRACT FROM AUTHOR]

Photonic microring resonator (MRR)-based hardware accelerators have been shown to provide disruptive speedup and energy-efficiency improvements for processing deep convolutional neural networks (CNNs). However, previous MRR-based CNN accelerators fail to provide efficient adaptability for CNNs with mixed-sized tensors. One example of such CNNs is depthwise separable CNNs. Performing inferences of CNNs with mixed-sized tensors on such inflexible accelerators often leads to low hardware utilization, which diminishes the achievable performance and energy efficiency from the accelerators. In this article, we present a novel way of introducing reconfigurability in the MRR-based CNN accelerators, to enable dynamic maximization of the size compatibility between the accelerator hardware components and the CNN tensors that are processed using the hardware components. We classify the state-of-the-art MRR-based CNN accelerators from prior works into two categories, based on the layout and relative placements of the utilized hardware components in the accelerators. We then use our method to introduce reconfigurability in accelerators from these two classes, to consequently improve their parallelism, the flexibility of efficiently mapping tensors of different sizes, speed, and overall energy efficiency. We evaluate our reconfigurable accelerators against three prior works for the area proportionate outlook (equal hardware area for all accelerators). Our evaluation for the inference of four modern CNNs indicates that our designed reconfigurable CNN accelerators provide improvements of up to $1.8\times $ in frames-per-second (FPS) and up to $1.5\times $ in FPS/W, compared to an MRR-based accelerator from prior work. [ABSTRACT FROM AUTHOR]

In this paper, a concept of a reconfigurable chipless radio frequency identification (RFID) sensor tag for detecting solvent vapors/gas in IoT applications was presented. The concept was based on the authors' previously published rectangular loop structure equipped with a U-folded dipole loaded with a glide-symmetrical interdigital capacitor coated with a thin layer of tetrasulfonated copper phthalocyanine deposited as a sensing layer to improve the sensing capability in the presence of acetone vapor. In order to further maximize the sensitivity of the designed structure to the desired solvent, a circuit for a central frequency adjustment using a radio frequency varactor diode biased with a wireless power transfer (WPT) was designed. By varying the DC bias of the diode, a continuous tunable range of approximately 200 MHz was achieved. The proposed reconfigurable wireless sensor tag was manufactured and the frequency shift was verified by measurement. The proposed external frequency control can be applied to a wide class of electrical resonators. [ABSTRACT FROM AUTHOR]

Research on so‐called "chemical artificial intelligence" (CAI) is an emerging field with the aim of constructing information‐processing systems with learning capabilities based on chemical methodologies. This can be regarded as an attempt to reconstruct Cybernetics using molecular based systems. Many chemical reaction systems with computational abilities are proposed, but most are fixed functions that deliver molecular output for a given molecular input. On the other hand, chemical AI is a system with learning capability; namely, the output should be variable and gradually change upon repeated molecular inputs. In this paper, a compartmentalization approach for implementing cellular chemical AI using liposomes is discussed. The existing studies in terms of the methods used for assembling systems consisting of many liposomes with different functions, methods for achieving recursiveness and plasticity in chemical reaction systems, and methods for reconfiguring the network topology by liposome deformation are reviewed. Issues that must be addressed in order to realize chemical AI are also identified. [ABSTRACT FROM AUTHOR]

This article proposes an active frequency selective surface (FSS) with application to satellite multi‐band antennas in X and Ka bands. The FSS offers two reflective bands at 20 and 30 GHz (downlink and uplink frequencies of broadband communication satellites in Ka‐band) under one biasing state, whereas the frequency characteristics are switched in X‐band (between 9 and 12 GHz, frequencies used for broadcast satellite services and space exploration) under the second biasing state. The unit cell of the FSS consists of three metallization layers, including four PIN diodes on the bottom layer that provide reconfigurability in X‐band. The FSS performance has been analyzed using an equivalent circuit model diagram, which provides a better understanding of the operation principle. The proposed FSS exhibits a robust transmission response for incidence angles up to 40°. Several samples of the FSS formed by a 2 × 4 cell array have been fabricated and measured in a waveguide simulator to confirm the results of the electromagnetic simulations at the lower operating frequencies. [ABSTRACT FROM AUTHOR]

There are several Rubik Cube types; their internal structure is complex, making them harder to understand, analyze, and design. Since the Rubik's Cube is a complex mechanism consisting of a large number of parts, its reconfigurable theory and bifurcation characteristics need to be studied. Thus, this paper first presents the piece matrix for each Rubik's Cube piece based on its motion characteristics, taking the classic third-order Rubik's Cube and Square-1 Rubik's Cube as examples. This allows the authors to explain the meaning of elements within the piece matrix. The Rubik's Cube reconfigurable configuration model is established next, and its reconfigurable motion model and the associated configuration are given. The Rubik's Cube reconfigurable motion model in any configuration is obtained by using the transformation matrix. The Rubik's Cube bifurcation characteristics are analyzed on the basis of reconfigurable configuration model. The work at hand improves the existing reconfigurable theory of Rubik's Cube mechanism and offers beneficial classification cubes to the subsequent research and synthesis. [ABSTRACT FROM AUTHOR]

Emerging memristive devices offer enormous advantages for applications such as non-volatile memories and in-memory computing (IMC), but there is a rising interest in using memristive technologies for security applications in the era of internet of things (IoT). In this review article, for achieving secure hardware systems in IoT, low-power design techniques based on emerging memristive technology for hardware security primitives/systems are presented. By reviewing the state-of-the-art in three highlighted memristive application areas, i.e. memristive non-volatile memory, memristive reconfigurable logic computing and memristive artificial intelligent computing, their application-level impacts on the novel implementations of secret key generation, crypto functions and machine learning attacks are explored, respectively. For the low-power security applications in IoT, it is essential to understand how to best realize cryptographic circuitry using memristive circuitries, and to assess the implications of memristive crypto implementations on security and to develop novel computing paradigms that will enhance their security. This review article aims to help researchers to explore security solutions, to analyze new possible threats and to develop corresponding protections for the secure hardware systems based on low-cost memristive circuit designs.

In this paper, we present a study on a broadband transparent tapered slot antenna. In general, the objective of achieving optical transparency is to enable antennas to seamlessly integrate into windows, offering an aesthetically pleasing and inconspicuous appearance. The aim of our research is to develop antennas that possess the ability to adjust horizontal plane beams across a wide frequency range, from 24 to 28 GHz, for 5G applications. This structure combines three antennas into a single unit, providing an advantage in terms of saving space. Furthermore, this structure offers the possibility of choosing between using a single antenna to obtain a directional beam in the −90°, 0°, or +90° directions (depending on the activated antenna) corresponding to three states, or the combination between two states to obtain another three additional states. The combination of the three states also allows for the acquisition of another state. At this point, the total number of states is 23 − 1. Only three PIN diodes are employed to switch between all states. Additionally, by adjusting the bias values of the PIN diodes, which function as variable resistors, the antenna beamwidth can be adjusted in order to achieve a coverage of 300°, offering more radiation pattern reconfigurability. The proposed method offers several advantages, including simplicity and feasibility in controlling the beamwidth and the beam direction electronically. This structure can be easily integrated into the development of fifth-generation communication systems.

• Inspired by SSH model, topological state in multi-stable metamaterial is studied. • Ligament-oscillator multi-stable metamaterial is designed based on bistable curve. • The designed element is proved bistable/reconfigurable by compression experiment. • Topology edge state in designed structure is found numerically and experimentally. Multi-stable mechanical structures find cutting-edge applications across various domains due to their reconfigurability, which offers innovative possibilities for engineering and technology advancements. This study explores the emergence of topological states in a one-dimensional chain-like multi-stable mechanical metamaterial composed of bistable units through a combination of mechanical and optical experiments. Drawing inspiration from the SSH (Su-Schrieffer-Heeger) model in condensed matter physics, we leverage the unique mechanical properties of the reconfigurable ligament-oscillator metamaterial to engineer a system with coexisting topological phases. Based on the one-dimensional periodic bistable chain, there is an exponential decay diffusion of elastic energy from both end boundaries towards the interior of the body. Experimental characterizations demonstrate the existence of stable topological phases within the reconfigurable multi-stable mechanical metamaterial. The findings underscore the potential of reconfigurable mechanical metamaterials as versatile platforms for flexibly exploring and manipulating topological phenomena, with applications ranging from impact resistance to energy harvesting and information processing. [ABSTRACT FROM AUTHOR]