Electronic Switching Research Articles

Investigation of healing electronic pressure-sensitive soft switch based on liquid metal microfiber

Flexible and wearable electronics have gained extensive attention in health monitoring, electronic skin, and sensors due to their flexibility, portability, sensitivity, and biocompatibility. Liquid metal (LM) is an optimum conductive material for soft electronic devices because of its high conductivity and fluidity at room temperature. Nevertheless, LM electronic devices with stable dimension is a formidable challenge due to its relatively high surface tension and mass density. In this study, we introduce a wet spinning approach that utilises sodium alginate as the exterior phase and LM as the interior phase. Calcium lactate is used to solidify the sodium alginate, thereby producing liquid metal microfibers (LMMs). The LMMs can be modified by adjusting the flow rate of the two-phase materials. The encapsulated LM microcapsule can serve as a healing electronic soft switch that is suitable for use in wearable and flexible electronic devices. Initially, the liquid metal soft switch (LMSS) has a high resistance value. Once a specific amount of pressure is applied, the resistance value drops considerably resulting in the switch’s activation. And LMMs coated by the sodium alginate can dissolve in a trisodium citrate solution, so that the LM can be reshaped under mixed each other. It achieves LMSS’s reusability and recycling.

A Pattern Reconfigurable Antenna for Ka-band Application

In this paper, we present an easy and systematic design approach to realize a dual beam reflector antenna at Ka-band which produces a narrow beam and a wide beam in the boresight. These two beams can be independently selected mechanically or by means of an electronic switching circuit. An exclusive systematic design approach has been presented. Simple mathematical expressions have been used for the design of the reflector and feed horns. The complete antenna has been realized with aluminum and its performances were experimentally validated. It yields ≈11.44% impedance bandwidth. It produces ≈ 35.4 dBi gain in the narrow beam mode with a half power beamwidth of ≈ 4.4° × 3.7° and about ≈ 11.3 dBi gain in the wide beam mode with a 3 dB beamwidth of ≈ 46.5° × 46° at 28 GHz. In this present work, the patterns are swapped between a narrow-beam and a wide-beam in the broadside. The ratio of the wide-beamwidth to the narrow-beamwidth is about 11:1, which is substantially different from all earlier investigations.

Preventing partial discharge in liquid metal polymer composites under steep voltage pulses

Liquid metal polymer composites (LMPCs) offer viable solutions for deformable electronics, including sensors and actuators. To ensure the longevity of the deformable technologies, partial discharge (PD) must be mitigated as it causes premature material aging and device failure. While studies on the dielectric properties of LMPCs have mainly focused on AC voltage, a large number of deformable applications will inevitably involve power electronics for higher efficiency and power density. Consequently, addressing PD in LMPCs under repetitive steep voltage pulses generated by power electronic switches becomes important. This study employs an electric field cancellation technique using electrets to reduce the PD magnitude and increase the partial discharge inception voltage (PDIV) of LMPCs under steep square voltage waves. We placed either a non-electret or electret thin film on top of LMPC samples and conducted PD experiments in flat and bent test coupon arrangements. The results show that electrets can reduce PD magnitude and increase PDIV in both test arrangements. Furthermore, the study provides deeper insights into the experimental results by conducting the electric field analysis of the LMPC experiments through numerical models.

Development of the Bipolar Junction Transistor Diagnostic Test (BJTDT) to explore the second-year undergraduate Myanmar electronic and Thai electrical engineering students’ understanding of BJT working principles and applications

ABSTRACT A bipolar junction transistor (BJT) and its operation are fundamental concepts for the understanding of power electronics (industrial electronics), transistor-transistor logic (TTL), electronic switching, and signal amplification in modern electronics. Previous research showed that non-major engineering, computer, electronic, and electrical engineering students could not understand the basic concepts involved in a BJT. This paper describes the development of a two-tier diagnostic test, the test’s administration, limitations, the participants’ detailed context, and findings from a study that explores Myanmar and Thai second-year undergraduate students’ understanding of BJT working principles and applications. The results revealed that many students in both countries had the same alternative conceptions about collector current in each operation mode of the BJT. Some alternative conceptions differ from the previous research, such as a) the collector current does not depend on the base current in cut-off mode, and b) changing the collector current does not depend on the base current in active mode, but it depends on the collector supply voltage. These research findings provide valuable information and instruments for teachers to insight, prevent, and correct the alternative conceptions proposed by students.

Synthesis and structures of cobalt-expanded zirconium- and cerium-oxo clusters as precursors for mixed-metal oxide thin films.

Transforming current complementary metal-oxide-semiconductor (CMOS) technology to fabricate memory chips and microprocessors into environmentally friendlier electronics requires the development of new approaches to resource- and energy-efficient electron transport and switching materials. Metal and multi-metal oxide layers play a key role in high-end technical applications. However, these layers are commonly produced through high-energy and high-temperature procedures. Herein, we demonstrate our first attempts to obtain stimuli-responsive mixed-metal oxide thin films from solution-processed molecular precursors under milder conditions. The molecular compounds of interest were prepared by one-pot reactions of a CoII carboxylate complex, triethylamine (Et3N), N-butyldiethanolamine (H2bda), and a hexanuclear complex [Ce6O4(OH)4(piv)12] (Hpiv = pivalic acid) or [Zr6O4(OH)4(ib)12(H2O)]·3Hib (Hib = isobutyric acid) in acetonitrile solution. The resulting charge-neutral, heterometallic coordination compounds display a ligand-supported pentanuclear {CeIV3CoIII2} core (in 1) and a dodecanuclear {ZrIV6CoII6} core (in 2), exhibiting thermal stability up to ca. 100 °C in air. Compound 2 was deposited and analyzed on Au(111) and SiO2/Si(100) surfaces to explore its potential as a single-molecule precursor for the preparation of atomically precise, complex mixed-metal oxide thin films. The adsorption characteristics of it demonstrate the ability to form stable agglomerates on the investigated surfaces.

Spin crossover in dinuclear iron(II) complexes bridged by bis-bipyridine ligands: dimer effects on electronic structure, spectroscopic properties and spin-state switching.

Inspired by the well-studied mononuclear spin crossover compound [Fe(H2B(pz)2)2(bipy)], the bipyridine-based bisbidentate ligands 1,2-di(2,2'-bipyridin-5-yl)ethyne (ac(bipy)2) and 1,4-di(2,2'-bipyridine-5-yl)-3,5-dimethoxybenzene (Ph(OMe)2(bipy)2) are used to bridge two [Fe(H2B(pz)2)2] units, leading to the charge-neutral dinuclear iron(II) compounds [{Fe(H2B(pz)2)2}2 μ-(ac(bipy)2)] (1) and [{Fe(H2B(pz)2)2}2 μ-(Ph(OMe)2(bipy)2)] (2), respectively. The spin-crossover properties of these molecules are investigated by temperature-dependent PPMS measurements, Mössbauer, vibrational and UV/Vis spectroscopy as well as X-ray absorption spectroscopy. While compound 1 undergoes complete SCO with T1/2 = 125 K, an incomplete spin transition is observed for 2 with an inflection point at 152 K and a remaining high-spin fraction of 40% below 65 K. The spin transitions of the dinuclear compounds are also more gradual than for the parent compound [Fe(H2B(pz)2)2(bipy)]. This is attributed to steric hindrance between the molecules, limiting intermolecular interactions such as π-π-stacking.

Reconfigurable Antennas for Wireless Communication: Design Mechanism, State of the Art, Challenges, and Future Perspectives

The rapid development of wireless technology has heightened the requirement for antenna performance. Traditional antennas, characterized by their static performance, are no longer sufficient to accommodate the dynamic requirements of modern wireless systems. The advent of reconfigurable antennas has opened new horizons for unleashing the full potential of wireless communication systems. These antennas are versatile and can switch various performance modes in a simple yet ingenious structure. Based on the cutting‐edge research, this paper deeply explores their core design principles, the latest breakthroughs, and the ingenious methods. Through an in‐depth analysis of a multitude of reconfigurable antenna design cases, existing design methods are categorized into four categories: electronic and optical switches, structural physical change, smart materials, and bistable composites. Each category is subjected to a meticulous dissection, revealing the underlying design mechanisms, highlighting innovativeness, and discussing both the strengths and limitations. Furthermore, by conducting a comprehensive comparative analysis, this paper concludes the forthcoming challenges and prospective trajectories for this research domain. Therefore, this paper can serve as a valuable reference for researchers seeking to deepen their understanding and application of various reconfiguration methods in the design of reconfigurable antennas, guiding them toward the forefront of antenna technology innovation.

Power factor correction of three-phase electrical power supply by using of thyristor controlled reactor VAR compensator

Low power factor (abbreviated as pf), particularly lagging pf, brings a lot of negative effects to electrical power supply system. Lagging pf is caused by inductive load. Inductive load with low pf draws higher current for the same active power demand. Higher current results in larger kVA rating and size of all electrical equipment connected to the electrical power system, larger conductor size used to deliver electrical power to the load, higher loss hence poorer power distribution efficiency and higher voltage drop hence poorer electrical power system voltage regulation. Considering all these negative effects, reactive power (VAR) compensation is needed. This paper analyses characteristics of a VAR compensation method called Thyristor Controlled Reactor (TCR) applied in three-phase electrical power system supplying an inductive load. A TCR consists of three sets of a capacitor connected in parallel with an inductor. The capacitor will supply a certain amount of reactive power needed by the load. The inductor is connected in series with an electronic static switch named as TRIAC to control the amount of reactive power absorbed by it. When reactive power supplied by the capacitor is higher than reactive power demanded by the load, the switching angle of TRIAC is controlled in such a way that excess of reactive power supply is absorbed by the inductor. In this work, three capacitors in which capacitance of each of it is equal to 50 µF as well as three inductors in which inductance of each of it is equal to 200 mH are used to compensate an inductive load which has power and pf vary from 1.5 kW to 4.6 kW and 0.46 to 0.84 respectively. By controlling the switching angle of TRIAC, pf of the three-phase electrical power system is successfully maintained close to unity at 0.95 following changes of the load. However, further analysis shows that operation of the TRIAC results in increase of current harmonics. Average of total current harmonic distortion (THD) increases from 15.13% to 18.45% due to use of TCR. On the contrary, voltage total harmonic distortion (THDV) after TCR installation is slightly lower than before TCR installation.

Application of a power electronic switch in a vacuum installation

This article proposes an original method of implementing a power electronic semiconductor switch using a technological process based on metal processing in a vacuum furnace. We give schematic diagrams of the power part and the control system, and oscillograms for their operation. Results from a practical application and experimental research on the operation of the vacuum installation are presented, and the variation in the glow discharge current with and without operation of the power electronic switch is explored. Photographs showing the details of the machining with and without the power electronic switch are included to demonstrate the effective operation of the proposed schematic solution.

PH-Controlled enzymatic computing for digital circuits and neural networks.

Unconventional computing paradigms explore new methods for processing information beyond the capabilities of traditional electronic architectures. In this work, we present our approach to digital computation through enzymatic reactions in chemically buffered environments. A key aspect of this approach is its reliance on pH-sensitive enzymatic reactions, with the direction of the reaction controlled by maintaining pH levels within a specific range. When the pH crosses a defined threshold, the reaction moves forward and vice versa, akin to the switching action of electronic switches in digital circuits. The binary signals (0 and 1) are encoded as different concentrations of strong acids or bases, offering a bio-inspired method for computation. The final readout is done using UV-vis spectroscopy after applying detection reactions to indicate whether the output is 1 (indicated by the presence of the enzymatic reaction's product) or 0 (indicated by the absence of the enzymatic reaction's product). We build and evaluate a set of digital circuits in the lab using our proposed methodology to model the circuits using chemical reactions. In addition, we demonstrate the implementation of a neural network classifier using our framework.

The OptoReg system: a simple and inexpensive solution for regulating water oxygen.

This paper describes an optocoupler-based regulation apparatus for saturation manipulation of oxygen in water (OptoReg). This system enables control of solenoid valves for oxygen and nitrogen gases using a FireSting-O2 meter, an optocoupler box and an electronic switch box. The hardware components connect to a computer through Universal Serial Bus (USB) cables. The control software is free and has a graphical user interface, making it easy to use. With the OptoReg system, any lab with a computer running Microsoft Windows operating system and a 4-channel FireSting-O2 meter can easily and cheaply set up four independently controlled systems for regulating water oxygen levels. Here, we describe how to assemble and run the OptoReg system and present a data set demonstrating the high precision and stability of the OptoReg system during static acclimation experiments and dynamic warming trials.

Tristate Converters with Limited Duty Cycle

Replacing the active switch of a DC/DC converter with a series connection of two active switches and a diode which is connected to the connection point of the two switches, changes the converter into a tristate one. The tristate concept changes the voltage transformation ratio of the original converter and influences the dynamics. Starting from a topology for limited duty cycles, four converters can be derived. There are two possibilities for the position of the second capacitor and so eight converter structures can be achieved. The position of the second capacitor influences the input current, the inrush, the stored energy, and the voltage stress of this component. When the input voltage has the other polarity, again eight converters can be designed. Changing all active electronic switches by current bidirectional ones (an electronic switch with an antiparallel diode) leads to bidirectional converters and increases the number of converters that are derived from the basic topology to thirty-two. The function of the four basic structures is explained, and the voltage transformation ratio calculated and graphically shown. The connections of the currents are explained. For one converter the large and the small signal models and two transfer functions are calculated, and simulation of the dynamics are shown.

Floating Tristate Double Boost Converter and a Modification

Two concepts are combined in this paper. First, the tristate concept, where the electronic switch of a DC/DC converter is replaced by a combination of two electronic switches and an additional diode. This leads to two interesting features: first the voltage-transformation ratio can be linearized and second the system can be transferred into a phase minimum system, which makes the control easier. The second two tristate Boost converters are combined to a floating double Boost converter. The basic function of the converter is explained. The large and the linearized small signal models are derived, transfer functions calculated, and Bode plots drawn. The dynamic behavior is studied with transfer functions and by circuit simulations done with LTSpice. The inrush is studied and a modification of the converter is shown to avoid dangerous overcurrents.

Hybrid Technique for Vibration Control using Synchronized Switch Damping on Inductor Modal Approach and Shape Memory Alloy Integration

Vibration control is a critical aspect of various engineering applications, including automotive and aerospace systems. This research paper presents a novel approach to enhance the performance of the Synchronized Switch Damping on Inductor (SSDI) technique by incorporating Shape Memory Alloys (SMAs). SSDI has proven effective in managing energy dissipation during electronic switching transitions, mitigating voltage spikes and reducing electromagnetic interference. However, the method consumes a substantial amount of energy. In this study, we propose a hybrid approach that combines the benefits of SSDI with the unique properties of SMAs to achieve improved vibration control. The integration of SMAs introduces a semi-passive element to the system, exploiting the inherent properties of these alloys to undergo reversible shape changes in response to external stimuli. By strategically placing SMAs within the vibration-prone components of the system, we aim to harness the mechanical forces generated during shape recovery to counteract and dampen vibrations. This innovative approach aims to capitalize on the efficient energy conversion capabilities of SMAs, thus minimizing the additional energy consumption associated with traditional semi-passive methods. The research involves theoretical modeling and simulation studies to assess the effectiveness of the proposed technique. Preliminary results demonstrate a significant reduction in vibration amplitudes and enhanced damping capabilities, validating the potential of the integrated SSDI-SMA system. The findings of this study not only contribute to advancements in vibration control methodologies but also provide insights into the broader applications of SMA-enhanced semi-passive techniques in improving the overall performance and efficiency of systems.

Hardware Implementation of a Single Phase 11-Level Novel SC-MLI with Reduced Component Count and Boosting Capability

Conversion of DC power into AC power at medium and high level utilize Multilevel-inverter (MLI) because of many advantages of MLI over conventional inverters. The MLI converter topologies have gained a huge attraction towards various applications like photovoltaic and even electric vehicles (EVs). This article represents a new switched capacitor topology (SC-MLI). The proposed SC-MLI contains ten power electronic switches and has a boosting capability with the help of one capacitor. It also uses two input DC sources and has a voltage gain of 1.4. Also, the capacitor is self-balancing and switches have less stress as compared to other configurations. Selective Harmonic Elimination (SHE) technique is employed for the generation of eleven levels. A comparison is also made with the recently developed MLI topologies based on different parameters. Finally, a hardware prototype is developed to check the feasibility of the proposed MLI in the laboratory and satisfactory results have been presented.

A novel extendable multilevel inverter for efficient energy conversion with fewer power components: Configuration and experimental validation

SummaryMultilevel inverters (MLIs) are widely used in various sectors of power electronics. Some major benefits of using MLI are the high‐quality voltage output, harmonic reduction, and efficiency. However, MLIs also bear a range of disadvantages including an excessive number of components, high total standing voltage (TSV), and complicated control scheme. Thus, a novel cross‐switched neutral point clamped (CSNPC) nine‐level inverter is proposed. Many of the suggested MLIs use a large number of DC supplies and additional switches that are not fully utilized and generate high power loss. However, the proposed MLI topology has a smaller number of power electronic switches and DC supplies, leading to higher energy efficiency. Moreover, a simplified high frequency modulation technique, named hysteresis‐band‐based discontinuous pulse width modulation (DPWM) is devised to control the proposed MLI. This modulation scheme has effectively minimized capacitor voltage imbalance. Furthermore, the designed structure is extendable to a modular MLI, without any additional H‐bridge circuit. To verify its benefits over other recent similar types of MLIs, a thorough comparison is presented for the number of components and power losses. The proposed MLI has showed 95.54% efficiency, and the modular CSNPC can achieve a total harmonic distortion (THD) of 6.43%.

Towards ultralow-power and high-speed electronics: Tunnel transistor based on single-chain Tellurium

The application of tunnel field-effect transistors (TFETs) in the sub-5.1 nm range meets the challenges of low on-state current (Ion), elevated leakage current (Ileak) and a limited bias range with sub-thermionic subthreshold swing (SS) characteristics. Here, by the design of gate-all-around (GAA) single-chain Te (1Te) TFETs, the sub-thermionic SS characteristics span nearly six orders of magnitude of drain current, overcoming the above challenges. While there usually exists trade-offs between maximizing Ion and minimizing Ileak, our optimized 5.1 nm GAA 1Te TFET defies this convention. Its steep turn-on characteristics result in an ultra-low Ileak of 7.9 × 10−10 μA/μm coupled with a high Ion of 1352 μA/μm, surpassing other low-dimensional materials-based FETs. These exceptional performances are attributed to the desirable properties from ultra-thin 1Te, including its moderate bandgap, anisotropic effective mass, and reduced screening length. Crucially, this device demonstrates key figure of merits for digital electronics that fulfill both the requirements of high-performance and low-power device specified by the International Technology Roadmap for Semiconductors, indicating the potential as energy-efficient and high-speed electronic switch. Our findings are expected to stimulate further research into sub-5.1 nm quasi-1D materials-based TFETs and provide valuable insights for optimizing their performance.

Methylene Blue-Stained Single-Stranded DNA Aptamers as a Highly Efficient Electronic Switch for Quasi-Reagentless Exosomes Detection: An Old Dog with New Tricks.

Improving the convenience, sensitivity, and cost-effectiveness of electrochemical biosensors is crucial for advancing their clinical diagnostic applications. Herein, we presented an elegant approach to construct electrochemical aptasensors for tumor-derived exosome detection by harnessing the alterable interaction between methylene blue (MB) and DNA aptamer. In detail, the anti-EpCAM aptamer, named SYL3C, was found to exhibit a strong affinity toward MB due to the specific interaction between MB and unbound guanine bases. Thereby, SYL3C could be stained with MB to arouse a strong electrochemical signal on a gold electrode (AuE). Upon binding to EpCAM-positive exosomes, SYL3C underwent a conformational transformation. The resulting conformation, or exosomes-SYL3C complex, not only reduced the accumulation of MB on SYL3C by obstructing the accessibility of guanines to MB but also impeded the transfer of electrons from the bound MB to AuE, leading to a notable decrease in the electrochemical signal. Using MB-stained SYL3C as an electronic switch, an electrochemical aptasensor was readily established for the detection of EpCAM-positive exosome detection. Without the need for signal amplification strategies, expensive auxiliary reagents, and complex operation, this unique signal transduction mechanism alone could endow the aptasensor with ultrahigh sensitivity. A limit of detection (LOD) of 234 particles mL-1 was achieved, surpassing the performance of most reported methods. As a proof of concept, the aptasensor was applied to analyze clinical serum samples and effectively distinguish non-small-cell lung cancer (NSCLC) patients from healthy individuals. As EpCAM exhibits broad expression in exosomes derived from different tumor sources, the developed aptasensor holds promise for diagnosing other tumor types.

Tristate Converters

In the continuous inductor current operation the tristate DC/DC converters have three modes. In the first mode, the active switches are on and energy is transferred into the coil. In the second mode, the coil is short-circuited and the current in the coils stays constant, and in the third mode, the free-wheeling diode takes over the current. In the here used concept the active switch of the original converter is replaced by a series connection of two active switches and an additional diode is connected to the connection point of the two electronic switches. The other terminal of the diode is connected to the coil. This concept was originally applied to the Boost converter. In this paper, it is shown that the same idea can be applied to other DC/DC converters and the Buck and the Buck-Boost converters are shown. It is also possible to apply the concept to converters of higher order. Here the Cuk, Zeta, and SEPIC are treated. It is also possible to apply it to quadratic converters and the d-square converter is taken as an example. A converter with a reduced duty cycle is also treated and a modification that avoids the inrush current is also shown. Finally, an improved superlift converter is treated. The position of the zero of the transfer function is exemplarily studied.

Fabrication of SiC-on-Insulator (SiCOI) Layers by Chemical Vapor Deposition of 3C-SiC on Si-in-Insulator Substrates at Low Deposition Temperatures of 1120 °C

Compared to bulk silicon carbide (SiC) wafers, SiC-on-insulator (SiCOI) substrates enable new device designs of electronic switches as well as novel photonic applications. One application is a micro-resonator for the usage in a Kerr frequency comb. For SiCOI substrates, a deposition temperature below 1200 °C is advisable due to stability reasons of the buried oxide layer during chemical vapor deposition (CVD) process conditions. To create 3C-SiC-on-insulator layers, a cold-wall CVD reactor was utilized, with propane and silane as the sources for carbon and silicon, respectively. To improve the cracking of the carbon source gas at low temperatures, the inner setup of the utilized cold-wall CVD reactor was changed to a non-water-cooled system. The change of the inner reactor setup was investigated numerically, and the grown epitaxial layers were characterized by Raman, EDX, SEM-imaging and XRD spectroscopy. We demonstrate successful deposition of 3C-SiC epitaxial layer substrates at temperatures below 1200 °C without delamination on SOI.