Array Module Research Articles

A Wearable Dual-Mode Probe for Image-Guided Closed-Loop Ultrasound Neuromodulation.

Low-intensity focused ultrasound (FUS) is an emerging non-invasive and spatially/temporally precise method for modulating the firing rates and patterns of peripheral nerves. This paper describes an image-guided platform for chronic and patient-specific FUS neuromodulation. The system uses custom wearable probes containing separate ultrasound imaging and modulation transducer arrays realized using piezoelectric transducers assembled on a flexible printed circuit board (PCB). Dual-mode probes operating around 4 MHz (imaging) and 1.3 MHz (modulation) were fabricated and tested on tissue phantoms. The resulting B-mode images were analyzed using a template-matching algorithm to estimate the location of the target nerve and then direct the modulation beam toward the target. The ultrasound transmit voltage used to excite the modulation array was optimized in real-time by automatically regulating functional feedback signals (the average rates of emulated muscle twitches detected by an on-board motion sensor) through a proportional and integral (PI) controller, thus providing robustness to inter-subject variability and probe positioning errors. The proposed closed-loop neuromodulation paradigm was experimentally demonstrated in vitro using an active tissue phantom that integrates models of the posterior tibial nerve and nearby blood vessels together with embedded sensors and actuators.

High-spatiotemporal resolution microwave-induced thermoacoustic tomography for imaging biological dynamics in deep tissue

Biological systems undergo constant dynamic changes across various spatial and temporal scales. To investigate the intricate biological dynamics in living organisms, there is a strong need for high-speed and high-resolution imaging capabilities with significant imaging depth. In this work, we present high-spatiotemporal resolution microwave-induced thermoacoustic tomography (HR-MTAT) as a method for imaging biological dynamics in deep tissues. HR-MTAT utilizes nanosecond pulsed microwave excitation and ultrasound detection, with appropriate spatial configurations, to achieve high coupling of the sample to the microwaves, to produce images in soft tissue with dielectric contrast and sub-millimeter spatial resolution (230 μm), to a depth of a few centimeters. Notably, by employing a 128-channel parallel signal acquisition and digitization strategy, the field programmable gate array module manages data synthesis, and GPU-based parallel pixel reconstruction facilitates HR-MTAT to accomplish single-frame image reconstruction in an impressive 50 μs. The practical feasibility of HR-MTAT was evaluated in live mice. The results show that HR-MTAT can noninvasively image whole-body small animals (up to 60 mm in depth) with clear resolution of internal organ structures at a frame rate of 100 Hz, without the need for labeling. At this high spatiotemporal resolution, HR-MTAT can capture respiration, heartbeat, and arterial pulse propagation without motion artifacts and track bio-nanoprobes in livers and tumors. These findings demonstrate HR-MTAT's ability to perform dynamic imaging with high contrast and resolution in deep tissues.

Prototyping and Experimental Analysis of Active Offloading Footwear for Patients With Diabetes Using an Array of Magnetorheological Fluid-Based Modules.

Diabetic foot ulceration is a serious challenge worldwide which imposes an immense risk of lower extremity amputation and in many cases may lead to the death. The presented work focuses on the offloading requirements using an active approach and considers the use of magnetorheological fluid-based modules to redistribute high plantar pressures (PPs). Experimentation validated a single module with a threshold peak pressure of 450 kPa, whereas an offloading test with a three-module array and complete footwear validated a maximum pressure reduction of 42.5% and 34.6%, respectively. To our knowledge, no such active and electrically controllable offloading footwear has been reported yet that has experimentally demonstrated PP reduction of more than 30% over the offloading site.

Chess Game Rook‐Icon Movement‐Based Photovoltaic Array Reconfiguration for Higher Shade Dispersion and Improved Global Power Peaks Under Partial Shading Conditions: An Experimental Study

Solar photovoltaic (PV) system generates low power because of nonuniform sun irradiation compared to standard test conditions. Partial shading conditions (PSCs) can arise from various factors, with passing clouds, trees, telecommunication towers, bird droppings, and similar elements being among the most prevalent causes. Under the shading scenario, multiple global and local maxima power points exist on the P–V curves. Herein, the chess game rules for the “Rook” icon are followed to attain the optimal placement of integer numbers (1–9) in the 9 × 9 size game puzzle matrix. The integer number‐based game puzzles such as Su‐Do‐Ku, symmetric matrix, and proposed Rook's movement‐game theory (RMGT) to rearrange the PV modules in arrays are investigated and compared with the standard arrangements such as series‐parallel, total‐cross‐tied during PSCs. The suggested RMGT puzzle‐based arrangement is able to achieve higher power at global maximum power point, performance enhancement, fill factor, and low power loss. As a result, the experimental study proves the superiority of RMGT configuration compared to conventional methodologies under the shading scenarios. The proposed RMGT‐based PV array is tested and obtained the performance higher side as, , , , and compared to existing reconfiguration methodologies.

Experimental Study on Spacing Effect in Arrays of Draft-Varying Floating WEC-Dikes

This study examines the impact of the spacing parameter on the efficacy of an array of hybrid modules functioning as both floating breakwaters and wave energy converters. The dual functionality is ensured by the ability of the device to autoadjust its submergence. The behavior of multiple 1:40 scaled modules was tested in the wave tank of the University of Campania “Luigi Vanvitelli”. The objective was to assess the hydraulic performance of the array by analyzing transmission, reflection, and dissipation coefficients under different wave conditions. Specifically, the transmission coefficient ranges between 0.85 and 0.51, depending on the relative wavelength and wave steepness, while the reflection and dissipation coefficients vary, respectively, between 0.70–0.20 and 0.55–0.3. In any case, the results underscore the critical importance of the spacing parameter.

SHIKSHA-CHAKRA: Ideate & Implement a System to Enhance Quality of Education in Rural Areas

Abstract: Access to quality education is a fundamental right, yet many rural areas face significant challenges in providing effective learning experiences to their students. To bridge this educational divide, this project introduces an innovative Androidbased system, known as the Rural Education Enhancement System (REES), designed to transform the landscape of education in rural regions. REES comprises a multifaceted approach, with key features including an interactive learning app offering subject-specific content, localized curriculum, and an array of interactive modules. The system facilitates teacher-student communication and provides tools for personalized progress tracking. Moreover, it prioritizes local languages and offers community forums for collaboration. Assessments, both online and offline, support student evaluation, while offline resource centers and parental involvement portals enrich the learning ecosystem. To ensure the system's longevity, sustainability planning is at the forefront, emphasizing funding, maintenance, and ongoing improvements. The project implementation involves thorough needs assessments, pilot programs, and community engagement. By addressing the unique needs of rural communities and leveraging the power of mobile technology, REES aspires to enhance the quality of education in rural areas, empower students, and strengthen the connections between teachers, parents, and the community, ultimately contributing to a brighter and more equitable educational future for all.

Exploring the Gut-Brain Axis: A Comprehensive Review of Interactions Between the Gut Microbiota and the Central Nervous System

The gut-brain axis represents a complex network of interactions among the gut microbiota, the enteric nervous system (ENS), the autonomic nervous system (ANS), and the central nervous system (CNS), exerting profound influences on both digestive and mental health. Dysfunction within this axis has been implicated in a spectrum of disorders ranging from irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) to depression, anxiety, and neurodegenerative conditions. While early observations of the relationship between emotions and gastrointestinal function date back to the early 20th century, recent decades have witnessed significant strides in understanding this intricate interplay, fueled by advancements in molecular biology, microbiology, and neuroscience. Key milestones include the discovery of the enteric nervous system, elucidation of gut hormone functions, and recognition of the pivotal role played by gut microbiota in shaping brain function and behavior. The gut microbiota, comprising trillions of microorganisms residing within the gastrointestinal tract, actively contribute to gut-brain communication by producing an array of metabolites, neurotransmitters, and immune modulators. This communication pathway underscores the critical importance of comprehending the intricate interplay between gut microbiota and the central nervous system for devising innovative therapeutic interventions targeting a broad spectrum of psychiatric and neurological disorders. Furthermore, lifestyle factors such as diet, stress, and antibiotic usage wield significant influence over the composition and functionality of gut microbiota, thereby emphasizing the pivotal role of lifestyle interventions in fostering and preserving gut-brain health. This abstract encapsulates the current understanding of the gut-brain axis, highlighting its multifaceted implications for health and disease management, and underscores the pressing need for continued research to unlock its therapeutic potential.

A Switched Z-Source and Switched Capacitor Multi-Level Inverter Integrated Low Voltage Renewable Source for Grid Connected Application

Most of the renewable sources generate power at lower voltage levels in the range of 20-50V which cannot be utilized by the loads. Therefore, stacking multiple modules in series increases the voltage level or using conventional boost converter or QZSis helpful. However, due to series stacking and boost converter or QZS there is a great power loss and also have reliability issues.The QZS inverter has very less boosting gain in the range of 2times. Theconventional boost converter or QZSis replaced with SZSC for voltage boosting and inverter operation. The SZSC boosts the voltage 4-5 times to the input voltage level. For further mitigation of harmonics, the conventional 6-switch inverter is replaced with switched capacitor MLI. Multiple renewable sources are at the input which include PV array, battery unit and PMSG wind module. The battery unit is a support to the renewable sources PV array and wind module. The DC link voltage stability is achieved by the battery unit placed in parallel to the renewable sources. The renewable sources share power to the grid through the SZSC and switched capacitor MLI. For DC voltage stability a CV control is integrated to SZSC. And for synchronized power sharing to the grid, a grid voltage feedback synchronization control is included for the control of MLI. A low rating renewable system is modelled and integrated to grid using Simulink MATLAB software. A comparative analysis is carried out operating the system with QZS and SZSC. The performances of the SZSC and MLI are evaluated by the graphs generated by the simulation of the modelled system.

Localized and extended collective optical phonon modes in regular and random arrays of contacting nanoparticles: Escape from phonon confinement

Localized and extended collective optical phonon modes in regular and random arrays of contacting nanoparticles: Escape from phonon confinement

Direct Optical Convolution Computing Based on Arrayed Waveguide Grating Router

AbstractOptical convolution computing is gaining traction owing to its inherent parallelism, multi‐dimensional processing, and energy efficiency. To handle input dimensions of N, conventional implementations necessitate N2 optical elements, such as Mach–Zehnder interferometers or micro‐ring resonators, to process multiply‐accumulate (MAC) operations, limiting scalability and resulting in elevated power consumption. Here, a direct convolution computing method based on wavelength routing, utilizing the unique sliding property of an arrayed waveguide grating router (AWGR) to perform the sliding window operation of the convolution in the wavelength–space domains is proposed. With two input vectors directly loaded onto two modulator arrays, the convolution result is instantaneously produced at a photodetector array. The entire convolution computation is executed within a single clock cycle without the need for preprocessing or decomposition into elementary MAC operations. The number of active elements is minimal, only needed for input/output. The proposed optical convolution unit has striking advantages of high scalability, high speed, and processing simplicity compared to those based on optical matrix‐vector multipliers. In the first experimental demonstration, a remarkable classification accuracy of up to 98.2% in handwritten digit recognition tasks using a LeNet‐5 neural network is achieved.

A 16 Gb/s serial link transceiver with active inductor based CTLE and 3-tap DFE in 12-nm FinFET CMOS

This paper presents a 16 Gb/s serial link transceiver implemented in 12-nm FinFET CMOS technology. The equalization scheme incorporates a 3-tap feed-forward equalizer (FFE) in the transmitter, a 5-stage continuous time linear equalizer (CTLE), and a 3-tap decision-feedback equalizer (DFE) in the receiver. The proposed FFE structure offers small step size and flexible configuration. The CTLE's high-frequency boost is augmented by integrating an active inductor. A high-accuracy clock and data recovery (CDR) circuit, featuring a cascaded two-step analog phase interpolator (PI) structure, is developed for data retiming. Occupying a footprint of 0.26 mm × 0.63 mm per lane, the transceiver test chip is packaged in a flip chip ball grid array (FC-BGA) module. Measurement results demonstrate a horizontal eye opening of 38 % at a bit error rate (BER) of 10−12 over a channel with 28 dB loss at 8 GHz. Moreover, the power consumption is 68.85 mW per lane at 16 Gb/s.

Long range topography by dispersion unmatched spectral-domain interferometry based on virtually imaged phased array modes.

We propose to realize a long range topography by dispersion unmatched spectral-domain interferometry based on virtually imaged phased array (VIPA) modes. By filtering the continuous spectrum of a supercontinuum source through a side-entrance Fabry-Perot etalon configured at two input angles, two groups of VIPA modes are generated. A method based on unmatched dispersion is proposed for non-aliasing reconstruction of the true depth from the interference spectrum under-sampled at two groups of VIPA modes. With the high spectral resolution provided by the VIPA modes instead of the grating-based spectrometer, only a 10 dB falloff in sensitivity over a range of 10 mm was demonstrated. The feasibility of the proposed method was confirmed by topography of a sample of gauge blocks and a model of three-dimensional (3D) printed tooth. The occlusal surface of the tooth model was further quantitatively evaluated, demonstrating its potential application in long range 3D topography.

Numerical Simulation of the Influencing Factors of Array Jet Shock Cooling

Array jet impingement cooling is a significant technology of enhanced heat dissipation which is fit for high heat flux flow with large area. It is gradually applied to the cooling of electronic devices. However, The researches on the nozzle array mode and the uniformity of cooling surface still have deficiencies. Therefore, the influence of heat flux, inlet temperature, jet height, array mode and diversion structure on jet impingement cooling performance and temperature distribution uniformity is analyzed by means of numerical calculation. The results show that the heat transfer coefficient of jet impingement cooling increases linearly with the increment of heat flux and inlet temperature. With the increment of the ratio of jet height to nozzle diameter (H/d), the heat transfer coefficient increases first and then decreases, that is, there is an optimal H/d, which makes the heat transfer performance of the array jet impact cooling best. The temperature uniformity of array jet impact cooling is greatly affected by array mode. The improvement effect of nozzle array mode on temperature uniformity is ranked as sequential > staggered > shield > elliptical array. The overall temperature uniformity and heat transfer coefficient are increased by 5.88% and 7.29% compared with elliptical array. The heat transfer performance can be further improved by adding a flow channel to the in-line array layout, in which the heat transfer coefficient is increased by 6.53% and the overall temperature uniformity is increased by 1.45%.

Modal acoustic emission-based circumferential crack feature extractions for pipeline welds with L-shaped flexible sensor array

ABSTRACT The collection and analysis of acoustic emission (AE) from weld circumferential cracks are crucial for ensuring pipeline safety. However, the unclear propagation characteristics and mode features of AE present challenges in array design and mode identification. In this manuscript, a novel mode feature extraction method for circumferential crack AE signals is proposed. This method involves three primary steps: firstly, a L-shaped flexible sensor array is designed to capture raw AE signals from both axial and circumferential directions. Next, the collected signals are filtered and evaluated to extract effective multi-mode components through the Kalman filtering and recursive plot (RP). Finally, the time–frequency features and mode types are extracted through combining the Hilbert-Huang transform (HHT) and dispersion curves. Results indicate that during the crack growths, both axial and circumferential direction AE signals contain multi-mode components, specifically L(0,1), F(1,1) and F(1,2) modes, with durations spanning 30–500 μs. Additionally, the axial modes predominantly occur within 200–300 kHz range, whereas the circumferential modes span both low and high frequency bands, specifically 40–50 kHz and 200–300 kHz, respectively. Modes across different frequencies indicate distinct structural behaviours, including crack growths and plastic deformations. The proposed method provides attempts for the pipe weld AE monitoring and multi-mode analysis.

A Novel Transparent Memristor‐Type Infrared Emissivity Modulator for Multispectral Compatible Display

The regulation of infrared (IR) thermal radiation has received widespread attention; the proposals have been made for various devices that use electrochromic materials. However, the visible appearance of the mentioned devices also changes when the IR states are altered. Herein, the memristive mechanism is utilized to regulate IR emissivity and design a novel transparent memristor‐type modulator featuring an Indium tin oxide (ITO)/HfO2/ITO structure. The modulator exhibits a dynamic emissivity variation of 0.38 in the IR region of 2.5–25 μm, without compromising transparency in the visible region under the application of an electric voltage. The migration of oxygen vacancies results in the modification of interface barriers and the formation of oxygen vacancy‐enriched regions, thereby enabling the modulator to exhibit resistive switching behavior and regulate IR emissivity. An array of modulators is also assembled, demonstrating the ability to independently display visible and IR information. In this work, new possibilities are presented for various applications such as multispectral displays, energy‐efficient thermoregulation, encrypted information displays, and camouflage.

Exploiting multi-stiffness combination inspired absorbers for simultaneous energy harvesting and vibration mitigation

In scenarios where wide-amplitude shock excitation is encountered, a routine bistable configuration struggles to achieve satisfactory energy transfer, and a sensible combination of multiple nonlinear oscillators with different stiffness mechanisms can be exploited to achieve optimal vibration mitigation performance. In this paper, a nonlinear energy conversion and multi-stiffness combination inspired dynamic vibration absorber (NECMC-DVA) is proposed with a magnetic-spring tunable nonlinear stiffness element as the substructure. Parametric studies are performed for different modes of magnet-spring tunable nonlinear stiffness unit arrays considering transient impulses and harmonic excitation. The NECMC-DVA device, which comprises bistable oscillators, cubic stiffness oscillators, and hybrid stiffness oscillators, is also experimentally demonstrated for its synergistic performance in vibration mitigation and energy harvesting. The performance of the NECMC-DVA is measured under transient impulses and harmonic excitations. It has been found that the NECMC-DVA, which consists of a bistable oscillator, a cubic stiffness oscillator, a hybrid stiffness oscillator, energy-capture elements, and motor sequences, achieves high-efficiency nonlinear energy transfer and significant shock robustness in wide-amplitude impulsive scenarios. The NECMC-DVA with hybrid energy sinks demonstrates more remarkable targeted energy transfer and energy conversion performance than its pure bistable oscillator counterpart. Furthermore, the NECMC-DVA prototype can achieve adaptive vibration control modulation and energy conversion management through motion control boards by monitoring ambient excitation signals. Therefore, the NECMC-DVA enables integrated active and passive mitigation and energy harvesting to simultaneously accommodate multi-source indeterminate vibration and shock environments.

Strong field enhancement and ultra-narrow linewidth based on the coupling of anapole/gap modes in silicon nanodimer-ring arrays

All-dielectric metamaterials have recently received significant attention in the field of nanophotonics, due to their negligible dissipative losses and strong polariton response compared with metallic metamaterials. However, simultaneously achieving an ultra-narrow resonance linewidth and a significant field enhancement in the all-dielectric metamaterials is still a great challenge, limiting their further practical application. In this work, a novel nanostructure composed of silicon ring and nanodimer arrays is theoretically proposed and numerically simulated. Through introducing the coupling between the anapole mode originating from the ring arrays and the gap mode deriving from the nanodimer arrays, the as-designed dielectric metamaterial manifests dual-band high-quality resonance characteristics with strong electric field enhancement reaching up to 300 times, an ultra-narrow linewidth as narrow as 0.35 nm, and a large Q-factor of 4223.43 synchronously. Benefiting from the exceptional optical spectral characteristics, the proposed dielectric nanodimer-ring metamaterial can work as a high-available refractive index sensor, whose sensitivity can reach 307.69 nm RIU−1 with its figure of merit attaining 879.11 RIU−1, efficiently distinguishing an index change of less than 0.01. This research opens up a promising path for achieving extremely narrow spectral linewidth and significant enhancement of the electric field, exhibiting immense possibilities in applications such as biochemical sensing, nonlinear optics, and surface enhanced spectroscopy.

WR‐3.4 multi‐mode waveguide module with single‐chip‐integrated array circuits

AbstractThis paper introduces a WR‐3.4 waveguide module that contains an array of circuits fabricated on a single chip with an area of 3 × 0.75 mm2. The array comprises ten elements, each containing a straight differential thru line connecting input and output waveguide transitions. Modifications to the edge element design are intended to produce perfect cell‐to‐cell symmetry by providing amplitude and phase balances for all array elements. The measurements show that the array module possesses an insertion loss of around 3.5 dB in the frequency range of 220–300 GHz. This result represents an increase of 2.5 dB compared to an empty waveguide module, displaying similarity to the performance of single‐element modules.

Coupling thermogalvanic and piezoresistive effects in a robust hydrogel for Deep-Learning-Assisted Self-Powered sign language and object recognition

The human hand provides rich sensory information for proper interaction with the environment. However, designing passive hand-sensing arrays with robust mechanical properties, high conductivity, ease of integration and reliability remains a long-term challenge. Here, we develop a robust dynamic crystalline ion-injected thermoelectric gel (DCI-TEG) via a simple solvent-exchange salt-out strategy. The resultant DCI-TEG exhibits high tensile strength (3.8 MPa), toughness (7.5 MJ m−3), and ionic conductivity of 1.84 S m−1. Benefiting from non-covalent crosslinking, the gel electrolyte and electrodes can be fully integrated into modules with tight physical and electrical contact, facilitating a stable and reliable signal output. By coupling thermogalvanic and piezoresistive effects, the DCI-TEG permits self-powered timely sensing of pressure using current signals. By implanting ionic thermoelectric module arrays on a glove, a wearable pressure sensing route is demonstrated with the merits of self-power, low cost and simple preparation. With the help of deep learning algorithms, a self-powered recognition for sign language and objects is realized in wearable/portable scenarios by active high-accuracy pressure detection. This work gives people a new direction toward barrier-free passive communication and human–machine interaction in the next-generation artificial intelligence.

Global Maximum Power Point Tracking of a Photovoltaic Module Array Based on Modified Cat Swarm Optimization

The main purpose of this study was to research and develop maximum power point tracking (MPPT) of a photovoltaic module array (PVMA) with partial module shading and sudden changes in solar irradiance. Modified cat swarm optimization (MCSO) was adopted to track the global maximum power point (GMPP) of the PVMA. Upon a sudden changes in solar irradiance or when certain modules in the PVMA were shaded, the maximum power point (MPP) of the PVMA will change accordingly, and multiple peak values may appear on the power–voltage (P-V) characteristic curve. Therefore, if the tracking pace is constant, the time required to track the MPP might extend, and under certain circumstances, the GMPP might not be tracked, as only the local maximum power point (LMPP) can be tracked. To prevent this problem, a maximum power point tracker based on MCSO is proposed in this paper in order to adjust the tracking pace along with the slope of the P-V characteristic curve and the inertia weight of the iteration formula. The initial voltage for tracking commencement was set to 0.8 times the voltage at the maximum power point of the PVMA under standard test conditions. Firstly, MATLAB 2022a was used to construct the four-series, three-parallel PVMA model under zero shading and partial shading. The feedback of PVMA voltage and current was obtained, where the GMPP was tracked with MCSO. From the simulation results, it was proven that, under different shading percentages and sudden changes in solar irradiance for partial modules in the PVMA, the MCSO proposed in this paper provided better tracking speed, dynamic response, and steady performance compared to the conventional CSO.