Array Of Applications Research Articles

Circularly Polarized Series Array and MIMO Application for Sub-Millimeter Wave/Terahertz Band

This article presents a compact, planar, and circularly polarized array antenna operating in the W-band (84.5–110 GHz), with all its prototypes fabricated using a low-cost, traditional, microwave printed circuit board composed of Rogers RT/duroid 5880 (ε<sub>r</sub> = 2.2, tanδ = 0.009). The final design that was fabricated and measured was a 4 × 4 array antenna having an overall size of 9 mm × 20 mm × 0.254 mm that used series feeding to reduce its sidelobes. Measurements of the 4 × 4 patch antenna array showed approximately 6.9% 3-dB axial ratio bandwidth along with 15.2 dBi maximum right-hand circularly polarized (RHCP) antenna gain at 100 GHz. The array antenna yielded RHCP radiation characterized by a low profile, low cross-polarization levels (<−25 dB), low sidelobe levels (≤−10 dB), and high radiation efficiency (>91%). Additionally, a two-port MIMO antenna system was investigated by considering side-by-side and front-tofront configurations, both of which achieved good isolation and considerable envelope correlation coefficient and diversity gain values. Therefore, the proposed series array and MIMO antennas can be reasonable candidates for 6G applications of the sub-THz band (100– 110 GHz) in ultra-high-speed wireless and satellite communication systems.

Amylase and Cellulase Production from Newly Isolated Bacillus subtilis Using Acid Treated Potato Peel Waste.

Species belonging to the genus Bacillus produce many advantageous extracellular enzymes that have tremendous applications on a commercial scale for the textile, detergent, feed, food, and beverage industries. This study aimed to isolate potent thermo-tolerant amylolytic and cellulolytic bacterium from the local environment. Using the Box-Behnken design of response surface methodology, we further optimized the amylase and cellulase activity. The isolate was identified by 16S rRNA gene sequencing as Bacillus subtilis QY4. This study utilized potato peel waste (PPW) as the biomaterial, which is excessively being dumped in an open environment. Nutritional status of the dried PPW was determined by proximate analysis. All experimental runs were carried out in 250 mL Erlenmeyer flasks containing acid treated PPW as a substrate by the thermos-tolerant Bacillus subtilis QY4 incubated at 37 °C for 72 h of submerged fermentation. Results revealed that the dilute H2SO4 assisted autoclaved treatment favored more amylase production (0.601 IU/mL/min) compared to the acid treatment whereas high cellulase production (1.269 IU/mL/min) was observed in the dilute acid treatment and was found to be very effective compared to the acid assisted autoclaved treatment. The p-value, F-value, and coefficient of determination proved the significance of the model. These results suggest that PPW could be sustainably used to produce enzymes, which offer tremendous applications in various industrial arrays, particularly in biofuel production.

A model-based sliding mode control with intelligent distribution for a proportional valve driven by digital valve arrays

Parallel-connected digital valve arrays are commonly utilized in the pilot stage of the proportional directional valve to enhance dynamic performance and reliability. However, when the digital valve array is driven by a digital signal, it is difficult to optimally assign the signal pulses to each valve. If the assignment is not well executed, it can significantly reduce the switching uniformity of the digital valves or lead to performance degradation of the system. In this paper, a model-based sliding mode control strategy based on the intelligent distribution of control law is proposed and successfully applied to a proportional valve driven by digital valve arrays. The intelligent distribution strategy encompasses a logic distribution algorithm and a circular sliding distribution algorithm that automatically assigns control laws to different valves based on the rolling of the PWM signal cycle. Experimental results confirm that the proposed strategy not only simultaneously reduces the total number of valve switches and enhances the switching uniformity among the valves, but also adapts to the variation in the number of valves. The proposed strategy is not limited to the application of digital valve arrays, it is also applicable in other fields of multi-actuators driven by digital signals, and can simultaneously improve the control accuracy, lifetime, and maintenance friendliness.

Ultrahigh extinction ratio and a low power silicon thermo-optic switch.

The silicon thermo-optic switch (TOS) is one of the most fundamental and crucial blocks in large-scale silicon photonic integrated circuits (PICs). An energy-efficient silicon TOS with ultrahigh extinction ratio can effectively mitigate cross talk and reduce power consumption in optical systems. In this Letter, we demonstrate a silicon TOS based on cascading Mach-Zehnder interferometers (MZIs) with spiral thermo-optic phase shifters. The experimental results show that an ultrahigh extinction ratio of 58.8 dB is obtained, and the switching power consumption is as low as 2.32 mW/π without silicon air trench. The rise time and fall time of the silicon TOS are about 10.8 and 11.2 µs, respectively. Particularly, the figure of merit (FOM) has been improved compared with previously reported silicon TOS. The proposed silicon TOS may find potential applications in optical switch arrays, on-chip optical delay lines, etc.

Tuning the Interfacial Chemistry of Nanoparticle Assemblies via Spin‐Coating: From Single Sensors to Monolithic Sensor Arrays

AbstractSensor arrays based on gold nanoparticle (GNP) films are promising candidates for numerous applications, including medical diagnosis and health monitoring. Their economic fabrication, however, remains challenging. This study presents a facile route to GNP chemiresistors with tunable properties via layer‐by‐layer spin‐coating (LbL‐SC). Key steps involve the alternating deposition of dodecylamine‐stabilized GNPs and mixtures of monothiols (MTs) with 1,9‐nonanedithiol (9DT). The 9DT molecules serve to reinforce the growing film via GNP cross‐linking while the MT ligands are used to tune the interfacial chemistry of the GNP assembly. Hence, by employing differently functionalized MTs the sensors' chemical selectivity can easily be adjusted. Further, by varying the MT‐9DT ratio and adjusting the size of the MT ligands the sensitivity can be tuned along with the conductivity and optical properties of the films. In general, decreasing the 9DT fraction significantly enhances the sensitivity while the response isotherms change from Langmuir‐Henry to Henry type. Finally, the cross‐linked GNP films are robust enough to be patterned via photolithography. Hence, this study demonstrates the fabrication and application of monolithic sensor arrays. Different features of the responses to numerous analytes are used as input data for linear discriminant analyses (LDA), revealing that very similar analytes can be distinguished.

Highly stretchable and customizable microneedle electrode arrays for intramuscular electromyography.

Stretchable three-dimensional (3D) penetrating microelectrode arrays have potential utility in various fields, including neuroscience, tissue engineering, and wearable bioelectronics. These 3D microelectrode arrays can penetrate and conform to dynamically deforming tissues, thereby facilitating targeted sensing and stimulation of interior regions in a minimally invasive manner. However, fabricating custom stretchable 3D microelectrode arrays presents material integration and patterning challenges. In this study, we present the design, fabrication, and applications of stretchable microneedle electrode arrays (SMNEAs) for sensing local intramuscular electromyography signals ex vivo. We use a unique hybrid fabrication scheme based on laser micromachining, microfabrication, and transfer printing to enable scalable fabrication of individually addressable SMNEA with high device stretchability (60 to 90%). The electrode geometries and recording regions, impedance, array layout, and length distribution are highly customizable. We demonstrate the use of SMNEAs as bioelectronic interfaces in recording intramuscular electromyography from various muscle groups in the buccal mass of Aplysia.

Application of Strain Selection Technology in Alcoholic Beverages: A Review.

The diversity of alcohol beverage microorganisms is of great significance for improving the brewing process and the quality of alcohol beverage products. During the process of making alcoholic beverages, a group of microorganisms, represented by yeast and lactic acid bacteria, conducts fermentation. These microorganisms have complex synergistic or competitive relationships, and the participation of different microorganisms has a major impact on the fermentation process and the flavor and aroma of the product. Strain selection is one of the key steps. Utilizing scientific breeding technology, the relationship between strains can be managed, the composition of the alcoholic beverage microbial community can be improved, and the quality and flavor of the alcoholic beverage products can be increased. Currently, research on the microbial diversity of alcohol beverages has received extensive attention. However, the selection technology for dominant bacteria in alcohol beverages has not yet been systematically summarized. To breed better-quality alcohol beverage strains and improve the quality and characteristics of wine, this paper introduces the microbial diversity characteristics of the world's three major brewing alcohols: beer, wine, and yellow wine, as well as the breeding technologies of related strains. The application of culture selection technology in the study of microbial diversity of brewed wine was reviewed and analyzed. The strain selection technology and alcohol beverage process should be combined to explore the potential application of a diverse array of alcohol beverage strains, thereby boosting the quality and flavor of the alcohol beverage and driving the sustainable development of the alcoholic beverage industry.

Temperature and strain gradient monitoring of the buoyancy material curing reaction with a submillimeter spatial resolution fs-FBG array

Millimeter-scale temperature and strain gradient measurements are crucial for understanding the mechanical properties of buoyancy materials. In this paper, we successfully fabricated ultrashort and high-density fiber Bragg grating (FBG) array based on femtosecond laser point-by-point writing technology. By optimizing the energy and number of femtosecond laser pulse, and introducing secondary tilt apodization technology, submillimeter-spatial-resolution FBG arrays were prepared. To the best of our knowledge, this is the first application of femtosecond FBG array for high spatial resolution temperature and strain gradient in situ monitoring of buoyancy materials. FBGs exhibit excellent anti-chirp performance and achieve submillimeter spatial resolution curing monitoring under temperature and strain monitoring gradients of 2.6 °C/mm and 231 με/mm, respectively.

Mixed-Modes-Enabled Element-Level Beamforming Antenna With Enhanced Isolation for Phased Array Applications

Mixed-Modes-Enabled Element-Level Beamforming Antenna With Enhanced Isolation for Phased Array Applications

Curved and Annular Diaphragm Coupled Piezoelectric Micromachined Ultrasonic Transducers for High Transmit Biomedical Applications.

In this paper, we present a novel three-dimensional (3D) coupled configuration of piezoelectric micromachined ultrasound transducers (pMUTs) by combing a curved and an annular diaphragm for transmit performance optimization in biomedical applications. An analytical equivalent circuit model (EQC) is developed with varied excitation methods to incorporate the acoustic-structure coupling of the curved and annular diaphragm-coupled pMUTs (CAC-pMUTs). The model-derived results align well with the reference simulated by the finite element method (FEM). Using this EQC model, we optimize the key design parameters of the CAC-pMUTs in order to improve the output sound pressure, including the width of the annular membrane, the thickness of the passive layer, and the phase difference of the driving voltage. In the anti-phase mode, the designed CAC-pMUTs demonstrate a transmit efficiency 285 times higher than that of single annular pMUTs. This substantial improvement underscores the potential of CAC-pMUTs for large array applications.

Design of novel differential power processing scheme for small-scale PV array application operating under partial shading conditions: modelling and experimental validation

In this study, an innovative approach known as Series and Parallel Differential Power Processing (SP-DPP) converters has been introduced and applied to a small-scale 2 × 2 PV array configuration. Unlike conventional methods, this approach employs Bidirectional Ćuk DC-DC Converters (BCC) in lieu of bypass diodes within serially connected PV modules, facilitating precise adjustment of module currents. Additionally, the Differential Power Processing (DPP) mechanism, utilising an Inverted-Buck Converter (IBC) topology, replaces traditional blocking diodes across parallel string connections. The paper develops mathematical models for these converters based on their transfer functions in the Continuous Conduction Mode (CCM), establishing new design criteria for SP-DPP systems. This approach ensures a well-behaved transient response and mitigates non-minimum phase response effects. Empirical testing demonstrates the efficacy of the proposed system under various static and dynamic partial shading conditions (PSCs). Furthermore, a model-based control strategy employing P + I controllers are formulated and experimentally validated to optimise the operating conditions of PV modules, enabling them to operate at their Maximum Power Points (MPPs) in varying lighting conditions. Through simulation and experimental results, the study affirms a substantial increase in the total output power of the SP-DPP system (approximately 37–41 %) compared to conventional Tied-Crossties (TCT) array configuration relying solely on bypass and blocking diodes under various static shading conditions, such as Short-Narrow (SN), Short-Wide (SW), Long-Narrow (LN) and Long-Wide (LW). Ultimately, this research highlights the novelty of the proposed SP-DPP scheme over other existing DPP schemes in the literature, in terms of maximum power extraction, cost and complexity under various lighting conditions. This research extends to explore the potential economic viability and global implications of large-scale DPP system implementation.

Formation of Anisotropic Conducting Interlayer for High-Resolution Epidermal Electromyography Using Mixed-Conducting Particulate Composite.

Epidermal electrophysiology is a non-invasive method used in research and clinical practices to study the electrical activity of the brain, heart, nerves, and muscles. However, electrode/tissue interlayer materials such as ionically conducting pastes can negatively affect recordings by introducing lateral electrode-to-electrode ionic crosstalk and reducing spatial resolution. To overcome this issue, biocompatible, anisotropic-conducting interlayer composites (ACI) that establish an electrically anisotropic interface with the skin are developed, enabling the application of dense cutaneous sensor arrays. High-density, conformable electrodes are also microfabricated that adhere to the ACI and follow the curvilinear surface of the skin. The results show that ACI significantly enhances the spatial resolution of epidermal electromyography (EMG) recording compared to conductive paste, permitting the acquisition of single muscle action potentials with distinct spatial profiles. The high-density EMG in developing mice, non-human primates, and humans is validated. Overall, high spatial-resolution epidermal electrophysiology enabled by ACI has the potential to advance clinical diagnostics of motor system disorders and enhance data quality for human-computer interface applications.

Breaking the left-right symmetry in fluttering artificial cilia that perform nonreciprocal oscillations

Recent investigations on active materials have introduced a new paradigm for soft robotics by showing that a complex response can be obtained from simple stimuli by harnessing dynamic instabilities. In particular, polyelectrolyte hydrogel filaments actuated by a constant electric field have been shown to exhibit self-sustained oscillations as a consequence of flutter instability. Owing to the nonreciprocal nature of the emerging oscillations, these artificial cilia are able to generate flows along the stimulus. Building upon these findings, in this paper we propose a design strategy to break the left-right symmetry in the generated flows, by endowing the filament with a natural curvature at the fabrication stage. We develop a mathematical model based on morphoelastic rod theory to characterize the stability of the equilibrium configurations of the filament, proving the persistence of flutter instability. We show that the emerging oscillations are nonreciprocal and generate thrust at an angle with the stimulus. The results we find at the level of the single cilium open new perspectives on the possible applications of artificial ciliary arrays in soft robotics and microfluidics.

A Novel Compact Wideband Planar Inverted-F Fishbone Antenna With Load-Bearing Capacity and Its Application in CP Arrays

A Novel Compact Wideband Planar Inverted-F Fishbone Antenna With Load-Bearing Capacity and Its Application in CP Arrays

Exploring the significance and applications of Field Programmable Gate Arrays in modern integrated circuits

In recent years, the rapid advancement of electronic technology and large-scale integrated circuit technology has led to increased integration of integrated circuits and expanding system scales on integrated motherboards. This evolution presents new challenges and demands in system design. Field Programmable Gate Arrays (FPGAs), a vital VLSI technology, have found extensive applications in communication, image processing, computers, and other domains, becoming a pivotal component of contemporary electronic systems. This paper aims to enhance the understanding of FPGAs by first delving into their theoretical foundations, followed by an overview of their general structural elements and a historical perspective on FPGA development. Additionally, this analyse and summarize relevant literature in the third section, focusing on the three primary application areas of FPGAs, elucidating their research processes and findings. Finally, the fourth section offers insights into the future directions of FPGA development, grounded in the current context. By acquainting readers with FPGAs essential attributes and its multifaceted applications, this paper underscores the pivotal role of FPGAs in the landscape of modern integrated circuits.

Microwave Loaded Line Phase Shifter Design for Beam-steering Applications in Adaptive Array Antenna System

In this scholarly work, we present innovative design for Loaded Line Phase Shifter (LLPS) which is tailored for the dynamic requirements of beam-steering adaptive antenna arrays. This phase shifter plays a pivotal role by installing a precise 90o phase shift into the elements of the adaptive array, enabling beam switching in diverse directions. In the absence of the Loaded Line Phase Shifter, the S-Parameter values, specifically S11 and S21, are recorded at 158.88o and -23.72o, respectively. Upon integrating the LLPS into the transmission line, a remarkable transformation occurs with S11 and S21 values transitioning to -143.28o and -53.03o, correspondingly. These results hold great promise for the practical applications of adaptive antenna arrays.

A novel design of hard-magnetic soft switch array for planar and curved surface applications

This paper proposes an array structure with multidirectional remanent magnetization based on hard-magnetic soft materials, which can be used as a soft switch array on planar and curved surfaces. We firstly investigate the displacement response of a hard-magnetic soft switch which is excited by a magnetic field, and related to the magnitude and direction of the magnetic field. When the remanent magnetization direction of the soft switch is opposite to the horizontal component of the magnetic field, the displacement response is greater than that of the driving magnetic field in other directions. The maximum displacement of the soft switch can reach 4.5 mm under a 6 V driving voltage applied to the Helmholtz coil. We further design 2 × 2 and 3 × 3 switch arrays and the circuit structures of the switch arrays. The switch arrays are fabricated, and the displacement responses of the switch arrays under different driving magnetic fields on planar and curved surfaces are finally demonstrated. When the Z-axis displacement of the device reaches more than 3 mm, the LED light can be switched on. The hard-magnetic soft switch array structure designed in this paper can enable the application of soft switches in curved environments, verifying the feasibility of the application of hard-magnetic soft switch arrays. It is expected to provide a guidance for the design and manufacturing of multi-functional hard-magnetic soft switches in the future and the application of hard-magnetic soft switch arrays in planar and curved environments.

Performance evaluation of linear antenna array using quasi opposition modified particle swarm algorithm

Linear antenna arrays find extensive application in the communication systems of the future, including IoT, 5 G, and beamforming technologies. However, sustaining subsidiary lobes while keeping a tight beamwidth remains a challenge. In this paper, an enhanced version of Artificial Hummingbird Algorithm (AHOA) is presented. AHOA is a kind of particle swarm algorithm based on the unique flying abilities and clever foraging techniques of hummingbirds seen in nature. In this research, a hybridization of AHOA and quasi opposition based learning is presented for linear antenna array applications. The quasi opposition learning based artificial hummingbird method has been developed to produce more accurate outcomes for further complicated tasks and is named as Quasi Opposition Based Artificial Hummingbird Algorithm. The approach is evaluated across various communication needs of the linear array, and the results are compared with those obtained from other conventional methods. In comparison to the other approach, the proposed strategy delivers the lowest subsidiary lobes along with the narrow beamwidth without any grating lobes. Thus, the proposed approach is capable of managing diverse linear array applications without sacrificing beamwidth or subsidiary lobes levels.

Subwavelength Bessel beam arrays with high uniformity based on a metasurface.

Bessel beam arrays are highly attractive due to non-diffraction properties, parallel processing, and large capacity capabilities. However, conventional approaches of generating Bessel beams, such as spatial light modulators, axicons, and diffraction optical elements, suffer from various limitations of system complexity and bulkiness, low uniformity, and limited numerical aperture (NA). The limited NA imposes constraints on achieving minimal full width at half maximum (FWHM) of the Bessel beam, ultimately compromising the resolution of the beam. In this study, we demonstrate a method for generating Bessel beam arrays with regular and random patterns via an ultra-compact metasurface. This approach integrates the phase profile of an optimized beam splitter with a meta-axicon. The Bessel beam arrays exhibit subwavelength dimensions of FWHM (590nm, ∼0.9λ) and relatively high uniformity of 90% for N A=0.2 and 69% for N A=0.4. Furthermore, the method achieves effective suppression of background noise and zeroth-order intensity compared to methods based on Dammann grating (DG) based metasurfaces. The proposed method highlights potential applications of Bessel beam arrays in various fields, such as laser machining, optical communication, and biomedical imaging.

Innovative ionic liquid pretreatment followed by wet disk milling treatment provides enhanced properties of sugar palm nano-fibrillated cellulose

In order to accommodate the increased demand for innovative materials, intensive research has focused on natural resources. In pursuit of advanced substances that exhibit functionality, sustainability, recyclability, and cost-effectiveness, the present work attempted an alternative study on cellulose nanofibers derived from sugar palm fiber. Leveraging an innovative approach involving ionic liquid (IL) pre-treatment, bleaching, and wet disc mill technique, nano-fibrillated cellulose (NFC) was successfully obtained from the sugar palm fiber source. Remarkably, 96.89% of nanofibers were extracted from the sugar palm fiber, demonstrating the process's efficacy and scalability. Further investigation revealed that the sugar palm nano-fibrillated cellulose (SPNFC) exhibited a surface area of 3.46 m2/g, indicating a significant interface for enhanced functionality. Additionally, the analysis unveiled an average pore size of 4.47 nm, affirming its suitability for various applications that necessitate precise filtration. Moreover, the surface charge densities of SPNFC were found to be −32.1 mV, offering opportunities for surface modification and enhanced interactions with various materials. The SPNFC exhibit remarkable thermal stability, enduring temperatures of up to 360.5 °C. Additionally, the isolation process is evident in a significant rise in the crystallinity index, escalating from 50.97% in raw fibers to 61.62% in SPNFC. These findings shed light on the vast potential and distinct features of SPNFC, opening the path for its application in a wide array of industries, including but not limited to advanced materials, biomedicine, and environmental engineering.