Electronic Devices Research Articles

Electromagnetic Interference Shielding Films: Structure Design and Prospects.

The popularity of portable and wearable flexible electronic devices, coupled with the rapid advancements in military field, requires electromagnetic interference (EMI) shielding materials with lightweight, thin, and flexible characteristics, which are incomparable for traditional EMI shielding materials. The film materials can fulfill the above requirements, making them among the most promising EMI shielding materials for next-generation electronic devices. Meticulously controlling structure of composite film materials while optimizing the electromagnetic parameters of the constructed components can effectively dissipate and transform electromagnetic wave energy. Herein, the review systematically outlines high-performance EMI shielding composite films through structural design strategies, including homogeneous structure, layered structure, and porous structure. The attenuation mechanism of EMI shielding materials and the evaluation (Schelkunoff theory and calculation theory) of EMI shielding performance are introduced in detail. Moreover, the effect of structure attributes and electromagnetic properties of composite films on the EMI shielding performance is analyzed, while summarizing design criteria and elucidating the relevant EMI shielding mechanism. Finally, the future challenges and potential application prospects of EMI shielding composite films are prospected. This review provides crucial guidance for the construction of advanced EMI shielding films tailored for highly customized and personalized electronic devices in the future.

Design, Development and Testing of Electronic Class Attendance using Fingerprint

Electronic Class Attendance System (e-CAS) is an easy way to keep track of attendance of students and lecturers in School. It will cover the requirements of the personnel department in terms of day-to-day monitoring of students' and lecturers activities. Hence, students’ attendance is an important issue every institution must take into consideration to be productive. Hence, this research aims to design, develop and test using fingerprints. The methodologies used were miniature techniques and image processing techniques for design and development. This target was mainly decomposed into image pre-processing, feature extraction and feature match. For each sub-task, some classical and up-to-date methods in literature were analysed. Based on the analysis, an integrated solution for electronic class attendance was developed for demonstration. However, Poison probability process, Biometrics as well as NP-chart of Quality control were adopted for classical statistical analysis of quality and functionality of the e-Class Attendance System (e-CAS). The project on electronic class attendance system was coded by PHP and the hardware was developed with ATMEGA series of microcontrollers. The result when experimented achieved the objective of improving the performance and consistency of the electronic class attendance system based on template matching techniques as well as class attendance for both students and lecturers.

High Efficiency n-Type Doping of Organic Semiconductors by Cation Exchange.

Achieving efficient doping in n-type conjugated polymers is crucial for their application in electronic devices. In this study, an n-type doping method is developed based on cation exchange that maintains a high doping level while ensuring a high degree of structural order, leading to significantly improved electrical conductivity. By investigating various dopants and ionic liquids, it is discovered that the choice of dopant influences doping efficiency, while the selection of ionic liquid affects cation exchange efficiency. Through careful selection of suitable dopants and ionic liquids, High doping levels are achieved remarkably in a short period, resulting in the highest conductivity (nearly 1×10- 2Scm-¹) compared to other doping methods for poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} (N2200). The findings highlight the robustness and efficiency of cation exchange doping as an effective approach for achieving high-quality n-type doping in conjugated polymers, thereby opening new avenues for the development of advanced polymer-based electronic devices.

Ultrahigh Energy-Storage in Dual-Phase Relaxor Ferroelectric Ceramics.

High-performance dielectric energy-storage ceramics are beneficial for electrostatic capacitors used in various electronic systems. However, the trade-off between reversible polarizability and breakdown strength poses a significant challenge in simultaneously achieving high energy density and efficiency. Here a strategy is presented to address this issue by constructing a dual-phase structure through in situ phase separation. (Bi0.5Na0.5)TiO3-BaTiO3-based relaxor ferroelectric ceramics are developed, creating a grain-separated dual perovskite phase structure using a facile solid-state reaction method. These ceramics feature two interactive relaxor phases with diversified nanoscale polar structures and heterogeneous grain boundaries, synergistically contributing to high polarization with low hysteresis, substantially increased resistivity, and suppressed electrostrain. Remarkably, a record-high energy density of 23.6Jcm-3 with a high efficiency of 92% under 99kVmm-1 is achieved in the bulk ceramic capacitor. This strategy holds promise for enhancing overall energy-storage performance and related functionalities in ferroelectrics.

Ultralow Contact Thermal Resistance between Bismuth Selenide Nanoribbons Achieved by Current-Induced Annealing.

Thermal resistance at interfaces/contacts stands as a persistent and increasingly critical issue, which hinders ultimate scaling and the performance of electronic devices. Compared to the extensive research on contact electrical resistance, contact thermal resistance and its mitigation strategies have received relatively less attention. Here, we report on an effective, in situ, and energy-efficient approach for enhancing thermal transport through the contact between semiconducting nanoribbons. By applying microampere-level electrical currents to the contact between Bi2Se3 nanoribbons, we demonstrate that the contact thermal resistance between two nanoribbon segments is reduced dramatically by a factor of 4, rendering the total thermal resistance of two ribbon segments with a contact approximately the same as that of the corresponding single continuous nanoribbon of the same length. Analysis suggests that the ultralow contact thermal resistance is due to enhanced phonon transmission as a result of enhanced adhesion energy at the contact, with marginal contributions from direct electron-phonon coupling, even for ohmic contacts. Our work introduces a broadly applicable electrical treatment approach to various contacts between conducting and semiconducting materials, which has important implications for the design and operation of nanoelectronic devices and energy converters.

Design and Application Prototype of soft starting Three-Phase AC Motor by Using Analog Electronics Control for Teaching Aids of Power Electronics Practice

In general, palm oil processing factories, from fresh fruit bunches to Crude Palm Oil, require three-phase electric motors to drive or rotate it. The problems that often arise when using three-phase electric motors simultaneously in large numbers will result in very large surges in the electric current, which can affect the performance of electronic devices. To overcome this problem, a prototype of a three-phase AC voltage regulator circuit was made by adjusting the SCR triggering delay angle using an analog electronics equipment control that can be used for three-phase motor soft start applications in a palm oil factory. This prototype will be used as a learning tool for the practical for Aceh Polytechnic students for power electronics courses. This system is built with a method where the three-phase source is first lowered using a transformer arranged in a star on the primary and secondary sides, then each voltage is compared to the ground using an IC LM324, which aims to produce pulses wave. This pulse then connected to a triangular wave generator circuit, this triangular wave is then compared with the DC source voltage from the potentiometer, which aims to regulate the SCR triggering angle of SCR via MOC3063 driver, where the load used is resistive and connected in a star. The measurement using an oscilloscope and observing the change of triggering angle for several variations of each phase, the different Vrms voltage between measurements compared to mathematical analysis influenced by several factors, including, the transformer is made of three transformers that not identically, the electronic components used are not in ideal condition, and observations on the oscilloscope are carried out visually using the eye and manually adjusting the potentiometer rotation so that the level of measurement accuracy between one person and another will produce different values.

E-waste management in achieving SDGS in Negara Brunei Darussalam: Maqasid Shariah Perspective

‘Electronic waste’, ‘Waste Electrical and Electronic Equipment’ or commonly known as ‘E-waste’ or ‘WEEE’ is referred to any electrical object or equipment that no longer possesses any value which has been disposed of by its owner. As other unused items, E-waste, which has not been used and thrown away as waste without being intended for reuse, becomes becomes a big problem to contemporary life. Due to its complex chemical component and inorganic toxic material, E-waste requires special treatment and management different from that of conventional waste. Incorporating e-waste management into the framework of Maqasid of the Shariah provides a holistic approach to achieving Sustainable Development Goals (SDGs) in Brunei. By harmonizing the protection of religion, life, intellect, progeny and wealth with sustainability principles, this approach not only tackles the environmental challenges associated with e-waste but also ensures the well-being of the community in a manner that is in line with the Islamic teachings. To carry out a detailed analysis of e-waste management in achieving SDGs in Negara Brunei Darussalam, a qualitative approach is adopted in order to fulfil the research objectives and a semi-structured interview method is used by the researchers. A total of 10 employees from 6 organizations (inclusive of both government and private sector) were interviewed. The results have shown issues, problems and threats posed by e-waste with time consuming, health concerns, and a lack of awareness to be the main highlights. Aside, an effort from the government body in introducing the ‘Extender Producer Responsibility (EPR) scheme’ in handling and managing e-waste was also discussed. By nurturing a culture of environmental responsibility, increasing awareness through education and implementing efficient waste management approaches, Brunei can not only address the immediate risks associated with e-waste but also contribute to the global pursuit of the SDGs in a way that is spiritually and materially rewarding.

Factors Affecting the Adoption of Electronic Procurement Systems in Public Institutions in Tanzania: Evidence from Tanzania Prisons in Morogoro Municipal

The study investigated the factors affecting the adoption of electronic procurement systems in public institutions in Tanzania, evidence from Tanzania Prisons in Morogoro Municipal. A survey research design and mixed research approach were utilized. The target population included procurement employees in Tanzania public institutions represented by Kingolwira Prison, Mkonowa Mara Prison, Kihonda Prison, and Remand Prison in Morogoro Municipal Municipality. The study involved 52 respondents. Purposive sampling technique wase used in selection of respondents where all respondents with knowledge on electronic procurement systems were used. Data was gathered through questionnaires with likert scale statements and analysed using descriptive statistics. In addition to that, data deduction techniques whereby conclusions were made by logically reasoning from general principles or theories to specific instances or outcomes based on the available data. User opinions on e- procurement adoption in Tanzanian public institutions highlight significant concerns about technological infrastructure, including hardware availability, software support, and internet reliability. While many acknowledge benefits such as reduced paperwork and enhanced efficiency, opinions vary on its effectiveness in reducing lead times and corruption. Security remains a critical issue, with mixed views on data accessibility and sharing safety. Overall, addressing infrastructure challenges and security concerns is crucial to ensuring successful implementation and broader user acceptance of e- procurement systems.

Utilizing IoT and Cloud Computing for Weather-Health Monitoring Application

In an era defined by increasing climate changes and an increasing importance of accurate weather information, there is a need for a smart IoT- based weather monitoring system. This paper proposes an innovative system that uses Internet of Things (IoT) technology to advance weather monitoring and global data accessibility using Cloud computing. By seamlessly connecting multiple devices, such as sensors, electronic gadgets, and automotive electronics, to the internet, this system offers a complete solution for monitoring environmental conditions such as temperature, relative humidity, pressure, and rain levels. Specialized sensors collect data, which is then transformed into graphical interface using an app, enabling real-time weather information access worldwide. This technology has the ability to rethink how we convey and analyze environmental data with optimal efficiency and reach in industries including agriculture, urban planning, and environmental research.

Effect of Epoxy Conductive Adhesive on Film Deformation During the Thermoforming Process for In‐Mold Electronic Devices

AbstractIn‐Mold Electronics (IME) is an innovative technology that allows the creation of 3D‐shaped electronic surfaces by combining printed electronics and In‐Mold Decoration (IMD). During the manufacturing process, the materials that integrate these devices, such as adhesive, must endure the transformation conditions of thermoforming. However, the adhesive rigidity may influence the deformation of the film during this process. In this study, both printed and hybridized samples are compared regarding their stretching and thickness reduction during the thermoforming process. The results indicate that the deformation of the hybridized samples differs from the printed ones, resulting in less stretching in areas near the adhesive, with stretching increasing as it steps away from where it is deposited. Thickness values are also affected, being greater around the adhesive and decreasing farther away. Therefore, the presence of the adhesive significantly impacts the behavior of the film during processing, a factor that must be considered in the design of IME devices to maximize the number of functional devices.

Graphene nanoribbon FET technology‐based OTA for optimizing fast and energy‐efficient electronics for IoT application: Next‐generation circuit design

AbstractThe Internet of Things (IoT) and portable electronic devices are pivotal in enhancing living standards, with battery efficiency and compact design being critical for these devices. Analogue sensors, integral to advanced artificial intelligence, often necessitate complex real‐time processing and actuation. This study examines the performance of one‐dimensional armchair graphene nanoribbons in graphene nanoribbon field‐effect transistors (GNRFETs). It compares graphene nanoribbon‐based triple cascode operational transconductance amplifiers (GNRFET‐TCOTAs) with conventional CMOS‐based TCOTA. The results reveal substantial enhancements in the GNRFET‐based TCOTAs: the pure GNR‐TCOTA variant shows a remarkable 33.8% increase in DC gain and significant improvements in transconductance, slew rate, and gain‐bandwidth, with enhancements of 8.48, 5.85, and 8.56 times, respectively. Furthermore, the pure GNRFET TCOTA exhibits higher speed, lower energy‐delay product, and settling time compared to Si‐CMOS‐based TCOTA. The study also investigates the impact of critical design parameters on circuit performance. Overall, the research highlights the potential of GNRFETs to optimize TCOTA circuits, offering a path towards more efficient and compact electronic devices, thereby advancing the state of nanoelectronics and supporting the growth of high‐performance IoT systems.

SCIENTIFIC AND METHODOLOGICAL APPROACH TO DETERMINING THE DEGREE OF DANGER OF AN AIR TARGET BY CREW OF A COMBAT VEHICLE WITH A TURRETED MACHINE GUN

In the course of hostilities in eastern Ukraine, the main threat to critical infrastructure is posed by airborne attack weapons, in particular, the “Shahed-136” kamikaze drone and its russian counterpart, the “Geranium-2”. A combat vehicle with a turreted machine gun mount, which is part of mobile fire groups, has a limited number of means that provide high-quality visual observation, detection and recognition of air targets. Therefore, the task of determining the degree of danger of a detected and recognized drone is relevant in order to make an adequate decision on its destruction. The paper considers methods for detecting and recognizing an aerial target, determining its angle and direction of movement by the human visual system using optical and electronic devices and optical means of visual observation. The article proposes a scientific and methodological approach that allows detecting and recognizing an aerial target such as a kamikaze drone and determining the degree of its danger, which minimizes the time for the commander of a combat vehicle equipped with turreted machine guns to make a quick and adequate decision on destruction.

Using Piezoelectric Elements to Convert Bio-Mechanical Pulsations into Electrical Energy for Energy Harvesting

On the Internet of Things (IoT) where all electronic devices are connected to the internet, a secure power supply is necessary. Energy harvesting technology is attracting attention as ”enabling technology” that expands the use and opportunities of IoT utilization. This technology harvests energy that dissipates around us, in the form of electromagnetic waves, heat, vibration, etc. and converts it into easy-to-use electric energy. Alternating current signals can be extracted from bio-mechanical pulsations using skin-attached piezoelectric elements with a protrusion, as we reported previously. However, we found that the maximum voltage of the extracted signal was unstable and low. This study demonstrates that piezoelectric elements can be stacked to stabilize and increase the maximum voltage, and that the extracted signal can be used to charge a capacitor, after rectification using a voltage-doubler rectifier circuit with Schottky barrier diodes.

“CAMPANHA DE ALERTA AOS RISCOS DO CIGARRO ELETRÔNICO.”

The DEF’S (electronic devices for smoking) were created under the pretext of helping smokers to quit the conventional cigarette, eventually attracting a new audience: young people. Through different flavors, flashy colors, practical formats, small and that fit in any pocket. In Brazil, it is forbidden to commercialize this product as a precaution against diseases that may arise. But it’s not hard to find them for sale. Severe lung injuries lead to addiction to nicotine. In addition, they can cause damage to the oral mucosa, irritation of the throat and eyes, rhinitis, pneumonia and other conditions. Serious problems that many young people and teens lack a knowledge that these e-cigarettes can cause. Accompanied by sharing among themselves that can lead to communicable diseases. The objective of this project is to disseminate predominant information on the use of electronic devices to young people and adolescents. It is expected that through this project we will be able to show the negative impacts of DEF’S (electronic devices for smoking).

Methodology and Database for the Quantification of the Technical Recyclability of Electrical and Electronical Equipment Demonstrated on a Smartphone Case Study

Assessing a given product’s design and its recyclability using mass flow analysis based on the material separation and recovery rates of individual recycling processes under realistic conditions can support design decisions promoting better recyclability. EN 45555 defines the calculation of the technical recyclability of electrical and electronic equipment (EEE). However, the lack of specific recycling rates for material or processes often leads to either too small or too high recyclability values. Herein, an extensive database of such recycling rates is presented. Moreover, the quality of recycling is considered. The typical classification into “recycled” and “lost” is expanded into four categories, namely “circular”, “recycled”, “alternate material recovery” and “lost”. The recycling rate database includes yields for all four categories and covers 30 materials for 14 recycling processes relevant in waste EEE (WEEE) treatment. These data enable a detailed calculation of the recyclability of various EEE for multiple recycling scenarios covering the entire WEEE recycling chain. Fraunhofer IZM performed an internal critical review of the data. The recycling rates database can act as a solid foundation for comparing the recyclability of various electronics in different scenarios and recyclability indices. For example, the recyclability of typical smartphones is investigated comparing different dismantling and recycling scenarios highlighting the potential of both database and methodology.

Direct Photopatterning of Colloidal Quantum Dots with Electronically Optimized Diazirine Cross-Linkers.

Colloidal quantum dots (QDs) with a wide color gamut and high luminescent efficiency are promising for next-generation electronic and photonic devices. However, precise and scalable patterning of QDs without degrading their properties and their integration into commercially relevant devices, such as digitally addressable QD light-emitting diode (QLED) displays, remain challenging. Here, we develop electronically optimized diazirine-based cross-linkers for nondestructive, direct photopatterning of QDs and, ultimately, building the active-matrix QLED displays. The key to the cross-linker design is the introduction of electron-donating substituents that permit the formation of ground-state singlet carbenes for air-stable and benign QD photopatterning. Under ambient conditions, these cross-linkers enable the patterning of heavy metal-free QDs at a resolution of over 13,000 pixels per inch using commercial i-line photolithography. The patterned QD layers fully preserved their optical and optoelectronic properties. Pixelated electroluminescent devices with patterned InP/ZnSe/ZnS QD layers show a peak external quantum efficiency of 15.3% and a maximum luminance of about 40,000 cd m-2, outperforming those made by existing QD patterning approaches. We further show the seamless integration of patterned QLEDs with thin-film transistor circuits and the fabrication of dual-color active-matrix displays. These results underscore the importance of designing photochemistry for QD patterning, and promise the implementation of direct photopatterning methods in manufacturing commercial QLED displays and other integrated QD device platforms.

Excellent Low-Frequency Microwave Absorption and High Thermal Conductivity in Polydimethylsiloxane Composites Endowed by Hydrangea-Like CoNi@BN Heterostructure Fillers.

The advancement of thin, lightweight, and high-power electronic devices has increasingly exacerbated issues related to electromagnetic interference and heat accumulation. To address these challenges, a spray-drying-sintering process is employed to assemble chain-like CoNi and flake boron nitride (BN) into hydrangea-like CoNi@BN heterostructure fillers. These fillers are then composited with polydimethylsiloxane (PDMS) to develop CoNi@BN/PDMS composites, which integrate low-frequency microwave absorption and thermal conductivity. When the volume fraction of CoNi@BN is 44 vol% and the mass ratio of CoNi to BN is 3:1, the CoNi@BN/PDMS composites exhibit optimal performance in both low-frequency microwave absorption and thermal conductivity. These composites achieve a minimum reflection loss of -49.9dB and a low-frequency effective absorption bandwidth of 2.40GHz (3.92-6.32GHz) at a thickness of 4.4mm, fully covering the n79 band (4.4-5.0GHz) for 5G communications. Meanwhile, the in-plane thermal conductivity (λ∥) of the CoNi@BN/PDMS composites is 7.31W m-1 K-1, which is ≈11.4 times of the λ∥ (0.64W m-1 K-1) for pure PDMS, and 32% higher than that of the (CoNi/BN)/PDMS composites (5.52W m-1 K-1) with the same volume fraction of CoNi and BN obtained through direct mixing.

Hybrid rib fabric electromagnetic shielding measurement in X-band

This study involves measurement and evaluation of the electromagnetic shielding effectiveness (EMSE) in the X-band frequency range of rib-knitted fabrics formed from hybrid conductors. Hybrid conductive fabrics were made by knitting copper, silver, and stainless steel conductors together with cotton yarn. The basic theory of EMSE is introduced, and the waveguide measurement setup described. The through-reflect-line calibration setup was used to obtain accurate results. After calibration of the established waveguide measurement setup, hybrid conductive fabrics were tested. The measurements were analyzed and the fabrics compared. The aim is to produce a hybrid fabric that is suitable for general use, has a good EMSE, is easy to produce, and offers low-cost high-frequency solutions. An easy-to-produce and low-cost EMSE material is required, especially in new-generation wearable flexible electronic devices and military applications.

Reactive Power Compensation Applications of Matrix Converter: A Systemic Review

Abstract An array of solid-state switches that link a source and load directly without a middle DC link make up matrix converters, bi-directional power electronic devices. Because of the intricacy of their control systems, matrix converters have historically had a limited industrial adoption. But in the last few years, the creation of simple and dependable commutation techniques has made matrix converter-based systems attractive substitutes for reactive power management. Comprehensive analysis of matrix converter control strategies for reactive power compensation is given in this work. We start with a summary of matrix converter technology. Subsequently, devices for the Flexible Alternating Current Transmission System (FACTS), systems for integrating renewable energy, and electric drives used for reactive power compensation during the past ten years are covered. An overview of direct and indirect matrix converter topologies is provided, together with an investigation of the several applications of these topologies for reactive power management. The performance of control strategies including model predictive control, space vector modulation, direct torque control, and others is then investigated and compared for reactive power compensation. At last, future study directions are noted. The research indicates that control methods and matrix converter technology have significantly advanced, indicating promise for more industrial reactive power compensation applications. Further expanding their reactive power compensation potential will be the ongoing development of cutting-edge matrix converter topologies and ever more complex control techniques.

Inert Liquid Exfoliation and Langmuir-Type Thin Film Deposition of Semimetallic Metal Diborides.

Graphite is one of only a few layered materials that can be exfoliated into nanosheets with semimetallic properties, which limits the applications of nanosheet-based electrodes to material combinations compatible with the work function of graphene. It is therefore important to identify additional metallic or semimetallic two-dimensional (2D) nanomaterials that can be processed in solution for scalable fabrication of printed electronic devices. Metal diborides represent a family of layered non-van der Waals crystals with semimetallic properties for all nanosheet thicknesses. While previous reports show that the exfoliated nanomaterial is prone to oxidation, we demonstrate a readily accessible inert exfoliation process to produce quasi-2D nanoplatelets with intrinsic material properties. For this purpose, we demonstrate the exfoliation of three representative metal diborides (MgB2, CrB2, and ZrB2) under inert conditions. Nanomaterial is characterized using a combination of transmission electron microscopy, scanning electron microscopy, atomic force microscopy, IR, and UV-vis measurements, with only minimal oxidation indicated postprocessing. By depositing the pristine metal diboride nanoplatelets as thin films using a Langmuir-type deposition technique, the ohmic behavior of the networks is validated. Furthermore, the material decomposition is studied by using a combination of electrical and optical measurements after controlled exposure to ambient conditions. Finally, we report an efficient, low-cost approach for sample encapsulation to protect the nanomaterials from oxidation. This is used to demonstrate low-gauge factor strain sensors, confirming metal diboride nanosheets as a suitable alternative to graphene for electrode materials in printed electronics.