Design Of Switch Research Articles

Exploring amorphous Ge-As-Se-Te as an active layer candidate in memristive devices

The implementation of resistive switches in neuromorphic computing and long-term data storage has been delayed by inherent difficulties in their fabrication process, their stability and reproducibility. Low operating voltages, high-density integration and low energy consumption are common challenges in resistive switch design. Here, we report the implementation of a resistive switch based on the amorphous semiconductor Ge15As25Se15Te45 (GAST) between an inert (W) and an active (Ag) electrode. The device was built using contact photolithography and standard microfabrication techniques, allowing the integration with traditional manufacturing processes. The device is able to switch at voltages as low as 0.15V and 0.6V, when operating in DC and pulsed conditions, respectively. Our results suggest that the adoption of mixed conductors such as GAST may yield devices that operate at low voltages and low energy for neuromorphic applications.

Design of multi-frequency point, high-isolation switches for micro-channel plate data acquisition.

In order to replace the phosphor screen of a proximity-gated x-ray framing camera with a readout circuit using a time-interleaved structure, this paper carries out the design of a high-isolation RF switch. In this paper, a Metal-Oxide-Semiconductor Field Effect Tube (MOSFET) switching circuit is designed to achieve high isolation and low insertion loss at 0.5-3GHz. This solves the problem that the switching circuit cannot be turned off properly due to the parasitic capacitance of MOSFETs in the process of RF signal transmission, resulting in signal feedthrough. It also ensures that the input signal can be transmitted to the output intact when the switching circuit is turned on. High isolation is achieved by using parallel resonance to increase the voltage division and series resonance to leak the current. The switch achieves 76 dB isolation and 0.07 dB insertion loss at 1GHz frequency. Isolation is increased by adding parallel branches near the 2 and 3GHz frequency points, achieving greater than 33 dB isolation from 0.5 to 3GHz.

Design and Control of an Analog Optical Switch Based on the Coupling of an Electrothermal Actuator and a Mass–Spring System

Extending the analog output function has become an important trend in current MEMS optical switches. The electrothermal actuator is a potential candidate for realizing the analog optical switch since the output displacement can be continuously controlled throughout its driving range. However, since most existing micromirrors employ the out-of-plane motion, which is directly driven by the actuator, the design flexibility is limited and the temperature effect cannot be ignored. In this article, an analog optical switch is designed based on the coupling of an electrothermal actuator, a mass–spring system, and a sidewall reflective optical path. The in-plane reciprocating motion of the sidewall reflection micromirror is realized through the coupling, with the load analysis of the optical switch being significantly simplified. A temperature decrease as high as 305.5 K can be achieved by the integration at an applied voltage of 15 V. The dynamic coupling mechanism is well explained by a multibody electro-thermal–mechanical model. Furthermore, a position sensorless control scheme is proposed to realize the analog output function and anti-interference of the coupling optical switch. The linear analog output is presented throughout the micromirror's displacement of 0–90.57 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m. We believe that this work is significant for providing a novel functional device in intelligent optical window, laser ignition system, optical neural computing, etc.

Protecting car engines and controlling their temperature by using shape memory alloy as an automatic mechanical cooling sensor

Shape memory alloys (SMA) are smart materials with a dual function as a sensor as well as an actuator that can generate cyclic contraction and extension when exposed to an increasing and decreasing temperature. In this work, the potential of SMA in the form of spring as an actuator that activates a warning system for detecting high temperatures in vehicle engine is investigated. The working principle of SMA spring is it activates thermomechanically to generate linear reciprocating motion as a result of the contraction (heated) and extension (cooled). This unique feature is employed in the design of a new type of smart automatic switch that regulates and controls the temperature of the vehicle engine instead of using conventional sensors such as thermocouple. The smart automatic switch has two poles positive and negative, where the positive pole represents the SMA spring, which is completely immersed in the water of the engine. While the negative pole is the operating shaft that collects all the parts of the smart switch and is installed on the engine body. A lab scale experiment was conducted to analyse the displacements and results shown that contraction of 20 mm can be produced from the SMA spring due to pulling force when the temperature of the engine increases from 50 ℃ to 80 ℃ and the recovery of the SMA spring to the original position can be obtained by the pushing force 0.5 N from a bias spring when the temperature decreased. From this experiment, a design of the smart switch is that can be utilized the shape memory function is presented. The simplified design proposed demonstrates the shape memory alloy as having good potential in automotive applications such as this as it low cost, space saving, silent operation, and simple in design aspect.

Research and experiments on low throttle loss switched inertance hydraulic systems based on inertive elements

Switching hydraulic inertial systems (SIHS) manipulate the interaction of inertial and capacitive components through switching valves to achieve the efficient and rapid pressure regulation. However, the opening and closing of the switching valve lead to fluid expansion and compression in the switched volume, which generates throttling losses in the switching valve transition cycle, resulting in substantial energy loss. Hydraulic soft switching is an essential means to solve the loss of switching valves. However, the poor resonance performance of the hydraulic system leads to arduousness in the soft switching design. Therefore, this paper proposes that a mechanical-hydraulic coupling mechanism can realize the soft switching. A new approach is proposed to realize soft switching with a parallel double-motor mechanism based on the new idea. The approach connects inertive elements, at the back, to the switching valve to suppress the sudden flow increase caused by the compressed fluid in the switched volume during the opening transition stage of the switching valve, thus effectively reducing the loss caused by the throttling flow of the switching valve. The new approach has been experimentally verified to reduce the throttling flow by 33%, resulting in an increase of the SIHS output efficiency by 10%–15%.

Design of a graphene RF MEMS switch for X–V band

In this paper, we propose a graphene RF MEMS switch design for the X–V band. The structural parameters of graphene, such as the number of layers, the thickness of the medium and the material of the upper electrode, were analyzed by HFSS simulation software. The drive voltage of the switch was found to be as low as 3 V. The switching time is 320 ns. The highest isolation is −47.46 dB@8 GHz; In the 2–56 GHz band, the isolation is better than −20dB. Moreover, we carry out the process design of the switch, including key techniques such as graphene beam fabrication and graphene transfer, it shows that the switch has a great application prospect in the future.

Rational design of small-molecule responsive protein switches.

Small-molecule responsive protein switches are powerful tools for controlling cellular processes. These switches are designed to respond rapidly and specifically to their inducer. They have been used in numerous applications, including the regulation of gene expression, post-translational protein modification, and signal transduction. Typically, small-molecule responsive protein switches consist of two proteins that interact with each other in the presence or absence of a small molecule. Recent advances in computational protein design already contributed to the development of protein switches with an expanded range of small-molecule inducers and increasingly sophisticated switch mechanisms. Further progress in the engineering of small-molecule responsive switches is fueled by cutting-edge computational design approaches, which will enable more complex and precise control over cellular processes and advance synthetic biology applications in biotechnology and medicine. Here, we discuss recent milestones and how technological advances are impacting the development of chemical switches.

Online evaluation of the distribution system resiliency criteria using Choquet‐based graph technique

AbstractNowadays, due to network expansions, system operators are dealing with natural events including system failures. Evaluating the system readiness to maintain the network interconnections during severe faults are known as an important challenge of today's distribution networks. To do this, this paper presents an online non‐model‐based scheme of evaluating the system resiliency and supplying critical loads within severe natural conditions. In this case, by developing system resiliency as multi‐metric decision making problem and proposing the Choquet integral and graph theoretic methodology, the system resiliency is evaluated. The proposed resiliency scheme is an online non‐model‐based approach can be used for all distribution system configurations with the potential of natural event failures. In this case, by proposing online resiliency criteria based on the system critical loads and branches and developing the proposed criteria on Choquet integral scheme in the form of optimization procedure, the system resiliency is evaluated. The validity of the proposed approach is carried out on two different systems including the IEEE 123‐bus test system and the Consortium for Electric Reliability Technology Solutions (CERTS) microgrid. Simulation results present effectiveness of the proposed scheme to provide proper protective switching strategy and design the system resiliency criteria for future distribution systems.

Developing a Novel Hierarchical VPLS Architecture Using Q-in-Q Tunneling in Router and Switch Design

Virtual Private LAN Services (VPLS) is an ethernet-based Virtual Private Network (VPN) service that provides multipoint-to-multipoint Layer 2 VPN service, where each site is geographically dispersed across a Wide Area Network (WAN). The adaptability and scalability of VPLS are limited despite the fact that they provide a flexible solution for connecting geographically dispersed sites. Furthermore, the construction of tunnels connecting customer locations that are separated by great distances adds a substantial amount of latency to the user traffic transportation. To address these issues, a novel Hierarchical VPLS (H-VPLS) architecture has been developed using 802.1Q tunneling (also known as Q-in-Q) on high-speed and commodity routers to satisfy the additional requirements of new VPLS applications. The Vector Packet Processing (VPP) performs as the router’s data plane, and FRRouting (FRR), an open-source network routing software suite, acts as the router’s control plane. The router is designed to seamlessly forward VPLS packets using the Request For Comments (RFCs) 4762, 4446, 4447, 4448, and 4385 from The Internet Engineering Task Force (IETF) integrated with VPP. In addition, the Label Distribution Protocol (LDP) is used for Multi-Protocol Label Switching (MPLS) Pseudo-Wire (PW) signaling in FRR. The proposed mechanism has been implemented on a software-based router in the Linux environment and tested for its functionality, signaling, and control plane processes. The router is also implemented on commodity hardware for testing the functionality of VPLS in the real world. Finally, the analysis of the results verifies the efficiency of the proposed mechanism in terms of throughput, latency, and packet loss ratio.

Dual-Responsive Fe3O4@Polyaniline Chiral Superstructures for Information Encryption.

Incorporating stimuli-responsive mechanisms into chiral assemblies of nanostructures offers numerous opportunities to create optical materials capable of dynamically modulating their chiroptical properties. In this study, we demonstrate the formation of chiral superstructures by assembling Fe3O4@polyaniline hybrid nanorods by using a gradient magnetic field. The resulting superstructures exhibit a dual response to changes in both the magnetic field and solution pH, enabling dynamic regulation of the position, intensity, and sign of its circular dichroism peaks. Such responsiveness allows for convenient control over the optical rotatory dispersion properties of the assemblies, which are further integrated into the design of a chiroptical switch that can display various colors and patterns when illuminated with light of different wavelengths and polarization states. Finally, an optical information encryption system is constructed through the controlled assembly of the hybrid nanorods to showcase the potential opportunities for practical applications brought by the resulting responsive chiral superstructures.

Inf uence of the variable geometry of the diverter nozzle on the metrological characteristics of a calibration unit with weighing devices

This article discusses the issues of improving the metrological characteristics, weight-dimensional and technical and economic indicators of calibration installations with weighing devices due to the introduction of a fl ow switch with a variable nozzle exit geometry into their design. It is assumed that the use of this design of the fl ow switch will solve the problem of fi lling the nozzle exit with water, reduce the dimensions of the hydraulic path, simplify the maintenance procedure, and reduce the cost of installations. A description of the design, principles of operation and a timing diagram of a fl ow switch with a variable nozzle exit geometry are presented. The local hydrodynamic characteristics of the water fl ow by a Pitot tube in the nozzle exit are studied with a change in its width in the mass fl ow rate range from 25 to 550 t/h. The optimal values of the nozzle cut width are experimentally determined depending on the value of the mass fl ow rate of the liquid, at which it is completely fi lled with liquid. A study of the metrological characteristics of a calibration installation with weighing devices, which includes a fl ow switch with a variable nozzle exit geometry, methods of indirect measurements and comparisons using a comparison standard in a wide range of liquid mass fl ow rates, has been carried out. The impact on the metrological characteristics of a calibration installation with weighing devices of the nozzle cut width in the investigated range of liquid fl ow is established. Graphical dependences of the expanded measurement uncertainty of the installation when reproducing the unit of liquid mass fl ow rate on the measurement time interval and on the mass fl ow rate of the liquid are presented. Based on the research results, the optimal values of the nozzle cut width and measurement time intervals were determined depending on the mass fl ow rates of the liquid when using a fl ow switch with a variable nozzle cut geometry. The expansion of the range of operation of weighing devices, which are part of the verifi cation installations with weighing devices, is justifi ed. According to the results of the research, the proposed design of the fl ow switch with a variable geometry of the nozzle exit is recommended for use in the design of new and modernization of installations for calibration with weight devices of fl ow switches.

Redox-Regulated Magnetic Conversions between Ferro- and Antiferromagnetism in Organic Nitroxide Diradicals.

Redox-induced magnetic transformation in organic diradicals is an appealing phenomenon. In this study, we theoretically designed twelve couples of diradicals in which two nitroxide (NO) radical groups are connected to the redox-active couplers including p-benzoquinonyl, 1,4-naphthoquinyl, 9,10-anthraquinonyl, naphthacene-5,12-dione, pentacene-6,13-dione, hexacene-6,15-dione, pyrazinyl, quinoxalinyl, phenazinyl, 5,12-diazanaphthacene, 6,13-diazapentacene, and 6,15-diazahexacene. As evidenced at both the B3LYP and M06-2X levels of theory, the calculations reveal that the magnetic reversal can take place from ferromagnetism to antiferromagnetism, or vice versa, by means of redox method in these designed organic magnetic molecules. It was observed that p-benzoquinonyl, 1,4-naphthoquinyl, 9,10-anthraquinonyl, naphthacene-5,12-dione, pentacene-6,13-dione, and hexacene-6,15-dione-bridged NO diradicals produce antiferromagnetism while their dihydrogenated counterparts exhibit ferromagnetism. Similarly, pyrazinyl, quinoxalinyl, phenazinyl, 5,12-diazanaphthacene, 6,13-diazapentacene, and 6,15-diazahexacene-bridged NO diradicals present ferromagnetism while their dihydrogenated counterparts show antiferromagnetism. The differences in the magnetic behaviors and magnetic magnitudes of each of the twelve couples of diradicals could be attributed to their distinctly different spin-interacting pathways. It was found that the nature of the coupler and the length of the coupling path are important factors in controlling the magnitude of the magnetic exchange coupling constant J. Specifically, smaller HOMO-LUMO (HOMO: highest occupied molecular orbital, LUMO: lowest unoccupied molecular orbital) gaps of the couplers and shorter coupler lengths, as well as shorter linking bond lengths, can attain stronger magnetic interactions. In addition, a diradical with an extensively π-conjugated structure is beneficial to spin transport and can effectively promote magnetic coupling, yielding a large |J| accordingly. That is, a larger spin polarization can give rise to a stronger magnetic interaction. The sign of J for these studied diradicals can be predicted from the spin alternation rule, the shape of the singly occupied molecular orbitals (SOMOs), and the SOMO-SOMO energy gaps of the triplet state. This study paves the way for the rational design of magnetic molecular switches.

Factors and Underlying Mechanisms That Influence the Repetitive Breakdown Characteristics of Corona-Stabilized Switches

The corona-stabilized switch has the potential to be a high repetition rate pulsed-power switching device, but there has been limited investigation into its repetitive breakdown stability and insulation recovery characteristics. Repetitive breakdowns of gas are characterized by a memory effect, where the subsequent breakdown process is inevitably influenced by the preceding one. However, there are still some issues that require further exploration in the current research on the mechanism of memory effect on repetitive breakdown characteristics. To clarify the factors and mechanisms that affect the repetitive breakdowns of corona-stabilized switches, this paper introduced optical observation methods into the experimental investigation. Through optical–electrical coupled diagnosis, the repetitive breakdown stability and insulation recovery performance of corona-stabilized switches under different working conditions and repetition frequencies were analyzed. The monotonic promoting effect of corona stabilization on switch insulation strength recovery is proposed as well as the non-monotonic and complex regulatory mechanism of corona stabilization on repetitive breakdown stability. The research results provide a theoretical and practical basis for clarifying the mechanism of repetitive corona-stabilized breakdowns and optimizing the design of corona-stabilized switches.

Demonstration of Enhanced Saturable Absorption in Upconverter Integrated MoS2 Heterostructure Thin Film Using Nanopulsed Green Laser

Upconverter/MoS2 heterostructure thin films fabricated by hydrothermal technique are confirmed by X‐ray diffraction and Raman studies. Field‐emission scanning electron microscopy (FESEM) and high‐resolution transmission electron microscopy (HRTEM) reveal the nanobelt structured MoS2 mingled with trapezoid structure fluoride upconverters and sphere‐shaped oxide upconverters. The films exhibit green () and red () emission. The influence of upconverters on the nonlinear absorption of MoS2 is exploited by Z‐scan technique using nanopulsed laser. Estimated ground‐state absorption cross section is higher than the excited‐state absorption cross section of the samples and it confirms the occurrence of saturable absorption. CeO2:Yb,Er@MoS2 exhibits stronger saturable absorption due to synergetic effects like higher linear absorption coefficient at 532 nm, stronger green emission, and reduced size. Results pave way for the design of optical switches, Q‐switches, and mode lockers using upconverter integrated MoS2 thin films.

Optimal allocation of clusters in stepped wedge designs with a decaying correlation structure.

The cluster randomized stepped wedge design is a multi-period uni-directional switch design in which all clusters start in the control condition and at the beginning of each new period a random sample of clusters crosses over to the intervention condition. Such designs often use uniform allocation, with an equal number of clusters at each treatment switch. However, the uniform allocation is not necessarily the most efficient. This study derives the optimal allocation of clusters to treatment sequences in the cluster randomized stepped wedge design, for both cohort and cross-sectional designs. The correlation structure is exponential decay, meaning the correlation decreases with the time lag between two measurements. The optimal allocation is shown to depend on the intraclass correlation coefficient, the number of subjects per cluster-period and the cluster and (in the case of a cohort design) individual autocorrelation coefficients. For small to medium values of these autocorrelations those sequences that have their treatment switch earlier or later in the study are allocated a larger proportion of clusters than those clusters that have their treatment switch halfway the study. When the autocorrelation coefficients increase, the clusters become more equally distributed across the treatment sequences. For the cohort design, the optimal allocation is almost equal to the uniform allocation when both autocorrelations approach the value 1. For almost all scenarios that were studied, the efficiency of the uniform allocation is 0.8 or higher. R code to derive the optimal allocation is available online.

A Numerical Design of High-Resistance and Energy-Efficient HTS Switch Based on Dynamic Resistance

Dynamic resistance effect introduces dissipative loss to the type-II high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</i> c superconductors, which is initially considered as a disadvantage for superconductors when it was first discovered. However, in some cases “dynamic resistance”, a unique effect, can be effectively exploited. Based on the dynamic resistance effect, the AC-magnetic-field-actuated high temperature superconducting (HTS) power switch is developed. It is the key component in the HTS transformer-rectifier flux pump (TRFP). The operating characteristics of power switch are vital to the performance and reliability of the transformer rectifier flux pump. In this paper, we compare three designs of HTS power switch with different stabilizer structures: striated stabilizer layers with wide and narrow strips as well as original non-striated stabilizer layers. The performance of HTS power switch is evaluated by several criteria, including off-state voltage and resistance, temperature rise, power loss, and energy conversion efficiency. This study will help design high-performance, low-loss, and energy-efficient HTS power switch based on “dynamic resistance” effect.

A convenient switch design for high time resolution and energy resolution in ion velocity imaging

Time-sliced velocity map imaging (VMI) has extensively been applied in photodissociation dynamics studies, thanks to its unique advantages, such as high energy resolution and no requirement of inverse Abel or Hankel transformations. However, its time resolution is generally insufficient for distinguishing adjacent m/z ions with a certain kinetic energy due to the overlapping of time-of-flight distributions. Herein, we have made a novel and convenient switch design for the common ion optics in three-dimensional (3D) VMI. By simply introducing two additional resistors out of the vacuum chamber, the strength ratio of the extraction and acceleration fields is easily changed from 3D VMI to two-dimensional (2D) VMI under optimized conditions, as well as a significant extension of free drift length, leading to a higher time resolution while maintaining the high energy resolution. As a result, 2D and 3D VMI can be quickly switched without breaking the vacuum and replacing the electrostatic plates.

Evolution of molecular switches for regulation of transgene expression by clinically licensed gluconate.

Synthetic biology holds great promise to improve the safety and efficacy of future gene and engineered cell therapies by providing new means of endogenous or exogenous control of the embedded therapeutic programs. Here, we focused on gluconate as a clinically licensed small-molecule inducer and engineered gluconate-sensitive molecular switches to regulate transgene expression in human cell cultures and in mice. Several switch designs were assembled based on the gluconate-responsive transcriptional repressor GntR from Escherichia coli. Initially we assembled OFF- and ON-type switches by rewiring the native gluconate-dependent binding of GntR to target DNA sequences in mammalian cells. Then, we utilized the ability of GntR to dimerize in the presence of gluconate to activate gene expression from a split transcriptional activator. By means of random mutagenesis of GntR combined with phenotypic screening, we identified variants that significantly enhanced the functionality of the genetic devices, enabling the construction of robust two-input logic gates. We also demonstrated the potential utility of the synthetic switch in two in vivo settings, one employing implantation of alginate-encapsulated engineered cells and the other involving modification of host cells by DNA delivery. Then, as proof-of-concept, the gluconate-actuated genetic switch was connected to insulin secretion, and the components encoding gluconate-induced insulin production were introduced intotype-1 diabetic miceas naked DNA via hydrodynamic tail vein injection. Normoglycemia was restored, thereby showcasing the suitability of oral gluconate to regulate in situ production of a therapeutic protein.

Tunable plasma-induced transparency of a novel graphene-based metamaterial

We present a straightforward metamaterial structure based on a graphene monolayer, which comprises a single graphene block and two graphene strips. This innovative design enables plasma-induced transparency (PIT) phenomenal generation by harnessing the interplay between bright and dark modes. To elucidate this phenomenon, we conduct comprehensive theoretical calculations that corroborate the findings of simulate results from finite difference time domain (FDTD). Furthermore, we explore the PIT phenomenon across various Fermi energy levels while also investigating the associated slow light effect in relation to the structural parameter, Fermi energy level, and carrier mobility. By increasing the carrier mobility from 0.4 to 3.4 m2/(V⋅s), the group index can be elevated from 80 to 430. Consequently, this graphene-based metamaterial holds promise for inspiring novel approaches to the design of modulators, optical switches, and devices for manipulating slow light.

Tunable terahertz graphene metamaterial optical switches and sensors based on plasma-induced transparency

A periodic metamaterial comprising three graphene-strips and four C-type graphene square-ring is proposed herein to realize plasmon-induced transparency (PIT). Based on the characteristics of graphene dynamic modulation, we effectively broaden of the transparent window the relative bandwidth to realize the broadband PIT. The influence of the polarized light angle on PIT is investigated, demonstrating that the polarization angle affects PIT significantly, the dynamic change from multiple plasma-induced transparency to single-PIT can be realized. By tuning the Fermi levels in the graphene, our proposed metamaterial structure allows preparing not only a multi-frequency optical switch with modulation degrees of the amplitude (MDA) up to 95.6% and insertion loss (IL) down to 0.315 dB at 5.35THz but also preparing optical switches with MDA > 90% and IL < 0.35 dB in bands ranging from 5.28 to 5.48THz. The refractive index sensitivity of metamaterials is also investigated, and the simulation results show that a sensitivity of 0.7 THz/RIU is achieved, meaning an excellent sensors can be prepared. Thus, the proposed structure provides a new idea for the design of terahertz multi-frequency switches and refractive index sensors.