Dual Array Research Articles

High-throughput fluorescence lifetime imaging flow cytometry

Flow cytometry is a vital tool in biomedical research and laboratory medicine. However, its accuracy is often compromised by undesired fluctuations in fluorescence intensity. While fluorescence lifetime imaging microscopy (FLIM) bypasses this challenge as fluorescence lifetime remains unaffected by such fluctuations, the full integration of FLIM into flow cytometry has yet to be demonstrated due to speed limitations. Here we overcome the speed limitations in FLIM, thereby enabling high-throughput FLIM flow cytometry at a high rate of over 10,000 cells per second. This is made possible by using dual intensity-modulated continuous-wave beam arrays with complementary modulation frequency pairs for fluorophore excitation and acquiring fluorescence lifetime images of rapidly flowing cells. Moreover, our FLIM system distinguishes subpopulations in male rat glioma and captures dynamic changes in the cell nucleus induced by an anti-cancer drug. FLIM flow cytometry significantly enhances cellular analysis capabilities, providing detailed insights into cellular functions, interactions, and environments.

Parallel Analogy Method for Measuring FRD of the FASOT-IFU

A fiber integral field unit (IFU) was chosen for the Fiber Array Solar Optical Telescope (FASOT) to obtain high-spectral-resolution polarization solar spectral images. This IFU features a dual-array-end design, complemented by a dozen slit ends. Each consists of 2 sub-slits corresponding to the dual array ends. In order to accurately and quickly measure the focal ratio degradation of 8064 fibers in FASOT-IFU, a parallel analogy method (PAM) for FASOT-IFU was proposed. This method primarily relies on characterizing the focal ratio based on the full-width at half-maximum (FWHM) of the fiber’s output spot, and the linear relationship between the output focal ratio of the spot and the FWHM. By precisely calculating the focal ratio of the positioning fiber in the FASOT-IFU and treating it as a reference, the output focal ratio of the working fiber can be obtained by comparing the FWHM of the working fiber spot and the positioning fiber spot at the same emission distance. The average value of the output focal ratio by PAM corresponding to the 4032 fibers from Array A of the IFU is 6.0 and the standard deviation is 0.6. The values corresponding to the Array B are 6.2 and 0.40, respectively. The mean value exceeds the contractually specified F/5.5, and the proportion of optical fibers with a focal ratio greater than 5.5 accounts for 88% of the total number of optical fibers, meeting the design requirements of the FASOT system.

Development of a toroidally resolved broadband ECE imaging system for measurement of turbulent fluctuations on the KSTAR.

The two electron cyclotron emission imaging (ECEI) systems installed at adjacent ports (G and H) on the KSTAR tokamak incorporate large-aperture mm-wave optics, broadband electronics, and high speed digitization (up to 1 MSa/s) for 2D and quasi-3D visualization of MHD-scale fluid dynamics. Recently, the ECEI systems have been proved to be capable of visualization of smaller scale fluctuations albeit with a limited spatiotemporal resolution and even capable of measurement of ion cyclotron harmonic waves by direct high-speed sampling of the ECE IF signals. A four-channel prototype subsystem with a higher sampling rate up to 16 GS/s has been integrated into the G-port ECEI system, enabling the measurement of plasma waves in the GHz range in the form of modulated ECE signals and characterization of high-frequency turbulence during the evolution of pedestal. To achieve higher toroidal resolution in the turbulence measurement, the H-port ECEI system is now being upgraded to have a toroidally dual detector array of 2(toroidal) × 12(vertical) × 8(radial) channel configuration and a high-speed subsystem of 2(toroidal) × 4 channel configuration. The new mm-wave optics has been designed via beam propagation simulation, and the measured performance of the fabricated lens indicates a toroidal resolution of 8-10cm depending on the focus position and zoom factor, allowing for the measurement of parallel wavenumber up to k‖ ∼ 0.8cm-1.

Tunable high-Q resonances based on the asymmetric nanohole array of phase-change material

Dielectric metasurfaces have made great progress over the past decade to enhance light-matter interaction. Recently, dielectric nanohole structures have been employed for the creation of dielectric metasurfaces. However, the optical characteristics of most dielectric nanohole structures remain fixed once they are manufactured. This study investigates the optical properties of Ge2Sb2Te5 (GST) film perforated with a periodic dual nanohole array. The GST dual nanohole array is capable of supporting multiple guided resonances and bound states in the continuum (BICs). By introducing asymmetry in the radius, BICs can be transformed into quasi-BICs with high-Q resonances. The wavelengths of guided resonances and quasi-BICs can be dynamically controlled through the phase transition of GST. Furthermore, modifying the gap allows for the achievement of active high-Q electromagnetically induced transparency, resulting from the interaction between one guided resonance and one quasi-BIC mode. The GST asymmetric nanohole array holds potential for applications in optical modulators, slow-light devices, and nonlinear optical devices.

Wind energy harvesting using electromagnetic dual and multi cantilever flutter array

This study investigates wind energy harvesting from electromagnetic dual cantilever flutter (DCF) and multi cantilever flutter (MCF) arrays. Initially, the bare DCF was tested under several wind speeds at four different gap distances to analyse and verify its behaviour. Results suggest that the characteristics of the DCF is ideal for electromagnetic energy harvesting. Two identical sets of wounded coils and magnets were then fixed onto the DCF to generate an induced voltage output from the anti-phase motion. Experimental findings demonstrated a significant power density of 11 × 10−3 mW/cm3 at a wind speed of 18.0 ms−1 when using shorter and thicker beams, which is comparable to previous flutter-based energy harvesters. An additional magnet-holding beam was then added beside the DCF beams to form a multi cantilever flutter (MCF) array of three identical beams. Visual observation confirms that alternate beams in the MCF array also flutter in an anti-phase motion. The power output per beam and power density recorded for the MCF array was 38.0% higher than the DCF harvester due to the increase in functional coil output and magnetic flux density. Finally, further analysis suggest that an odd number of beams is more favourable for electromagnetic MCF array harvesters.

Research on the Measurement System and Remote Calibration Technology of a Dual Linear Array Camera

Abstract In order to accurately measure the flight trajectory of the projectile in a long-distance target range, it is important to establish a vertical target measurement system with a two-line array camera at several positions along the range. In the present work, a calibration system using dual theodolites is proposed to calibrate the vertical target measurement system of a dual linear array camera at different positions along a long target range. The present study investigates the principle of intersection measurement in the vertical target measurement system with a double linear array camera and presents the projectile’s target coordinate measurement formula. The calibration method of the measurement system is developed based on an analysis of the parameters in the projectile coordinate measurement formula. The calibration method only requires calibration of the camera’s distortion coefficient, the optical axis angle, and the principal point, ensuring a simplified and expedited calibration process. After calibration, the vertical target measurement system with a 3 m × 3 m measurement area is simulated and analyzed, yielding an error distribution diagram and identifying the factors that influence the measurement accuracy of the projectile’s target coordinates.

A Compact MIMO Antenna Based on Modal Analysis for 5G Wireless Applications.

This article presents a planar, non-angular, series-fed, dual-element dipole array MIMO antenna operating at 28 GHz with the metasurface-based isolation improvement technique. The initial design is a single-element antenna with a dual dipole array which is series-fed. These dipole elements are non-uniform in shape and distance. This dipole antenna results in end-fire radiation. The dipole antenna excites the J1 mode for its operation. Further, with the view to improve channel capacity, the dipole array expands the antenna to a three-element MIMO antenna. In the MIMO antenna structure, the sum of the J1, J2, and J3 modes is excited, causing resonance at 28 GHz. This article also proposes a metasurface structure with wide stopband characteristics at 28 GHz for isolation improvement. The metasurface is composed of rectangle-shaped structures. The defected ground and metasurface structure combination suppresses the surface wave coupling among the MIMO elements. The proposed antenna results in a bandwidth ranging from 26.7 to 29.6 GHz with isolation improvement greater than 21 dB and a gain of 6.3 dBi. The antenna is validated with the diversity parameters of envelope correlation coefficient, diversity gain, and channel capacity loss.

Dual biological-clock controllable low-power fibrous synapse array based on heterojunction switched conductive filaments

Central and peripheral biological clocks are essential to regulate creatures’ circadian rhythms, mimicking the biological clock controlled neural and/or immunological responses are research hotspots in the emerging neuromorphic or brain-like systems. However, the current neuromorphic devices still depend on programmable frequency dividing and doubling machine clocks, the high system cost is a challenge to conduct sophisticated brain-like neuromorphic computing. Herein, a dual biological-clocks (including ambient light and endocrine) controllable fibrous synapse crossbar array is proposed. It is demonstrated and confirmed in this work, the Ag conductive filaments, which are critical in the conventional MXene synapses, can be successfully switched by differently biased MoS2/MXene heterojunction. The current and power of the unit fibrous synapse in positive/negative switching processes can reach as low as 460 pA/-170 pA and 330 pW/121 pW, respectively. Then, four kinds of logical calculations to the input light signals are accomplished by using the as-prepared fibrous synapse based logical gate. Meanwhile, the light and serotonin combined modulation on the synaptic currents are manifested and applied to simulate the immune-neural responses (memory and the memory exhausted) of T cells in the skin clock. More interestingly, two biological immune compensation mechanisms controlled by the central clock and peripheral clock, namely balanced and reset immune compensation, are also accomplished. This work may pave a new way for promoting the development of dual biological-clock regulated computations in neuromorphic systems.

Multi-piezoelectric energy harvesters array based on wind-induced vibration: Design, simulation, and experimental evaluation

The efficiency of a single piezoelectric energy harvester (PEH) is inadequate to meet the energy requirements of equipment, requiring the simultaneous operation of multiple PEHs. Consequently, this work conducts research on multi-piezoelectric energy harvesters (MPEH) array based on wind-induced vibration. Analyze the output characteristics of array configurations using simulation and experimental methods, including dual parallel array (PEH-2p), dual series array (PEH-2s), four-square array (PEH-4), and nine-square array (PEH-9) energy harvesters. The results indicate that the spacing ratio (L/D) is the primary factor influencing the output performance of the PEH array. Both of the starting and peak wind speeds of PEH-2p were below the reference value, but the power peak has increased. The starting wind speed of PEH-2s has been reduced, with a more significant improvement in the output performance of the downstream energy harvester compared to the upstream energy harvester. The output power of the downstream energy harvester has increased by 323.35 % in comparison to the reference value. Additionally, the PEH-4 demonstrates a boosting effect on the output power of both the upstream and downstream energy harvesters. The energy harvester in the center of the PEH-9 has the highest power peak, being 349.44 % higher than the reference value.

Method and system design for spectral imaging based on dual micro-lens array field-of-view segmentation

The function of a mask in the integral field imaging spectrometer (IFIS), which segments image and samples, leads to the drawback of low spectral energy transmittance. Here, we improve field-of-view segmentation method and propose a dual micro-lens array imaging spectrometer (DMAIS). DMAIS comprises a projection lens (PL), a segmentation collimation module (SCM), and a telecentric lens (TL). And SCM, based on a dual micro-lens array, is the core component of it. By employing a lens array focusing approach instead of aperture sampling, DMAIS effectively enhances energy transmittance and reduces spectral bending. The ZEMAX simulation results indicate that compared to IFIS, DMAIS demonstrates a 109.2% increase in energy transmittance and a 32.9% reduction in spectral bending.

A Dual Fluorescence Turn-On Sensor Array Formed by Poly(para-aryleneethynylene) and Aggregation-Induced Emission Fluorophores for Sensitive Multiplexed Bacterial Recognition.

Bacterial infections have emerged as the leading causes of mortality and morbidity worldwide. Herein, we developed a dual-channel fluorescence "turn-on" sensor array, comprising six electrostatic complexes formed from one negatively charged poly(para-aryleneethynylene) (PPE) and six positively charged aggregation-induced emission (AIE) fluorophores. The 6-element array enabled the simultaneous identification of 20 bacteria (OD600=0.005) within 30s (99.0 % accuracy), demonstrating significant advantages over the array constituted by the 7 separate elements that constitute the complexes. Meanwhile, the array realized different mixing ratios and quantitative detection of prevalent bacteria associated with urinary tract infection (UTI). It also excelled in distinguishing six simulated bacteria samples in artificial urine. Remarkably, the limit of detection for E. coli and E. faecalis was notably low, at 0.000295 and 0.000329 (OD600), respectively. Finally, optimized by diverse machine learning algorithms, the designed array achieved 96.7 % accuracy in differentiating UTI clinical samples from healthy individuals using a random forest model, demonstrating the great potential for medical diagnostic applications.

Viewing-Angle-Enhanced and Dual-View Compatible Integral Imaging 3D Display Based on a Dual Pinhole Array.

Conventional integral imaging (InIm) three-dimensional (3D) display has the defect of a small viewing angle and usually presents a single 3D image. In this paper, we propose a viewing-angle-enhanced and dual-view compatible InIm 3D display system. The crosstalk pixel areas within the conventional elemental images (EIs) that result in image crosstalk were effectively utilized either for viewing angle enhancement or for dual-view 3D display. In the viewing-angle-enhanced 3D display mode, a composite elemental image (CEI) that consisted of a normal EI and two view-enhanced EIs was imaged by a dual pinhole array and formed an extended 3D viewing area. A precisely designed mask array was introduced to block the overlapped rays between adjacent viewing areas to eliminate image crosstalk. While in the dual-view 3D display mode, a CEI was composed of image information of two different 3D scenes. With the help of the dual pinhole array and mask array, two different 3D images were reconstructed for the left and right perspectives. Experiments demonstrated that both the left and right sides were increased by 6 degrees from the conventional 3D viewing angle, and also, a dual-view 3D display effect that retains the same viewing angle as the conventional system was achieved. The proposed system has a compact structure and can be freely switched between two display modes.

Microseismic Event Location with Dual Vertical DAS Arrays: Insights from the FORGE 2022 Stimulation

Abstract We investigate the resolvability of a microseismic event location given a recording array composed of vertical distributed acoustic sensing (DAS) boreholes. We use a modified source-scanning algorithm that takes into account both P and S waves. We transform the brightness maps it produces into probability density functions (PDFs), over which we carry out a resolution and uncertainty analysis. We apply this approach to microseismic events recorded by two vertical DAS boreholes as part of the Frontier Observatory for Research in Geothermal Energy (FORGE) project. We show that for the specific acquisition geometry in FORGE, the horizontal location of the events cannot be determined, but their depth can, similar to results obtained with a single borehole. Using synthetic examples, we show that the recording array’s geometry is the limiting factor in the determination of the horizontal location. We investigate various possible recording geometries composed of idealized DAS-like vertical boreholes with varying locations and depths. We find that, besides the number of recordingd boreholes, their depth is the main factor influencing the location estimation uncertainty. The number and position of the boreholes mainly influence the spatial distribution of the PDF, whereas the boreholes’ depth mainly influences its size. Despite the simplicity of our analysis, it highlights the influence of the monitoring array design for microseismic events’ locating using vertical DAS arrays.

Influence of the Textile Reinforcement on the Joint Formation of Pin-Joined Composite/Metal Parts

AbstractHybrid components consisting of continuous fiber reinforced thermoplastic (CFRT) and steel components exhibit promising potential in advanced lightweight construction. However, the joining operation presents a significant challenge due to the materials’ distinct physical and chemical properties. This paper studies a joining method in which dual pin arrays protruding from the surface of the metal component are inserted into the locally heated CFRT component to create a form-fitting joint. The primary objective is to scrutinize the influence of various CFRT materials on joint formation and quantify the resulting properties. The fiber type (glass and carbon) and fiber architecture (unidirectional and bidirectional reinforcement) are varied. All materials could successfully be joined via the direct pin pressing process, while depending on the CFRT material, distinct characteristic fiber morphologies could be identified. Bidirectionally reinforced carbon fiber reinforced samples showed the highest overall strength, while unidirectionally glass fiber reinforced samples showed the highest energy absorption and second highest ultimate strength.

Active pixel image sensor array for dual vision using large‐area bilayer WS2

AbstractTransition metal dichalcogenides (TMDs) are a promising candidate for developing advanced sensors, particularly for day and night vision systems in vehicles, drones, and security surveillance. While traditional systems rely on separate sensors for different lighting conditions, TMDs can absorb light across a broad‐spectrum range. In this study, a dual vision active pixel image sensor array based on bilayer WS2 phototransistors was implemented. The bilayer WS2 film was synthesized using a combined process of radio‐frequency sputtering and chemical vapor deposition. The WS2‐based thin‐film transistors (TFTs) exhibit high average mobility, excellent Ion/Ioff, and uniform electrical properties. The optoelectronic properties of the TFTs array exhibited consistent behavior and can detect visible to near‐infrared light with the highest responsivity of 1821 A W−1 (at a wavelength of 405 nm) owing to the photogating effect. Finally, red, green, blue, and near‐infrared image sensing capabilities of active pixel image sensor array utilizing light stencil projection were demonstrated. The proposed image sensor array utilizing WS2 phototransistors has the potential to revolutionize the field of vision sensing, which could lead to a range of new opportunities in various applications, including night vision, pedestrian detection, various surveillance, and security systems.image

A Simple Dual Wideband Shared-Aperture Antenna Array with Wide Scanning Angle

A Simple Dual Wideband Shared-Aperture Antenna Array with Wide Scanning Angle

A 10-bit 33.3-kS/s 3.2-fJ/conversion-step single-ended counter-type SAR ADC with dual 5-bit CDAC arrays and counters in 65-nm CMOS

In this paper, an area-and-energy-efficient 10-bit single-ended (SE) counter-type (CT) analog-to-digital converter (ADC) with dual 5-bit capacitive digital-to-analog converter (DAC) arrays and dual 5-bit counters is presented. The 10-bit capacitive-DAC (CDAC) array and counter of the conventional counter-type structure are divided into two 5-bit CDAC arrays and counters, respectively. Significant improvements are achieved in comparison to the conventional counter-type ADC as follows: the capacitance of the most-significant-bit (MSB) capacitor is reduced by 96.88 % from 512C to 16C; the total capacitors are reduced by 93.75 % from 1024C to 64C; the total clock cycles required in the conversion phase are reduced by 93.94 % from 1023 to 62; the average switching energy is reduced by 98.55 % from 2390CV2 to 35CV2. The proposed ADC occupies a smaller area, performs much faster, and its power consumption is greatly reduced. This structure has a simple design with small sampling capacitor (32C) and does not require a rail-to-rail comparator compared to SAR ADCs. It is suitable for biomedical and multi-channel applications. The proposed ADC is post-layout simulated in 65-nm CMOS technology which occupies 0.016 mm2 area. This ADC has 85.43 nW power consumption, 9.64 ENOB on 33.33 kS/s sampling rate, and 3.23 fJ/conversion-step FOM.

Dual Band 1x4 Linear Metamaterial Bowtie Antenna Array for Autonomous Vehicle in Public Safety Band Communications

This research presents the design, simulation, and fabrication of a dual-band 1x4 linear metamaterial bowtie antenna array for applications in 5G wireless systems and public safety band communications. The single-element antenna is a compact dual-band structure with a complementary split-ring resonator (TCSRR) element, and it exhibits resonant frequencies of 3.5 GHz and 4.9 GHz, covering the sub-6GHz 5G spectrum and the public safety band. The antenna aray design is optimized for impedance matching and radiation efficiency. The 1x4 linear antenna array is designed with a quarter-wave transformer feed network and carefully controlled mutual coupling to enhance gain and directionality. Simulated and measured results confirm the performance of the array, with a reflection coefficient within -10 dB from 3.2 GHz to 3.85 GHz and from 4.55 GHz to 5.95 GHz and 3.45 GHz to 3.75 GHz and 4.45 GHz to 5.7 GHz, respectively. The array exhibits a peak realized gain of up to 8.7 dBi and efficient radiation patterns. This work offers promising insights into the development of antenna systems for advanced wireless communication applications and vehicle-to-vehicle communication in public safety band.

Analyzing the Impact of Diesel Exhaust Particles on Lung Fibrosis Using Dual PCR Array and Proteomics: YWHAZ Signaling.

Air pollutants are associated with exacerbations of asthma, chronic bronchitis, and airway inflammation. Diesel exhaust particles (DEPs) can induce and worsen lung diseases. However, there are insufficient data to guide polymerase chain reaction (PCR) array proteomics studies regarding the impacts of DEPs on respiratory diseases. This study was performed to identify genes and proteins expressed in normal human bronchial epithelial (NHBE) cells. MicroRNAs (miRNAs) and proteins expressed in NHBE cells exposed to DEPs at 1 μg/cm2 for 8 h and 24 h were identified using PCR array analysis and 2D PAGE/LC-MS/MS, respectively. YWHAZ gene expression was estimated using PCR, immunoblotting, and immunohistochemical analyses. Genes discovered through an overlap analysis were validated in DEP-exposed mice. Proteomics approaches showed that exposing NHBE cells to DEPs led to changes in 32 protein spots. A transcriptomics PCR array analysis showed that 6 of 84 miRNAs were downregulated in the DEP exposure groups compared to controls. The mRNA and protein expression levels of YWHAZ, β-catenin, vimentin, and TGF-β were increased in DEP-treated NHBE cells and DEP-exposed mice. Lung fibrosis was increased in mice exposed to DEPs. Our combined PCR array-omics analysis demonstrated that DEPs can induce airway inflammation and lead to lung fibrosis through changes in the expression levels of YWHAZ, β-catenin, vimentin, and TGF-β. These findings suggest that dual approaches can help to identify biomarkers and therapeutic targets involved in pollutant-related respiratory diseases.

Flow and acoustic fields investigation of noise reduction by micro vortex generators in supersonic nozzles

The role of micro-vortex generators (MVGs) in supersonic jet noise reduction is investigated. Studies are performed to understand the noise reduction mechanisms of these devices. MVGs are implemented on a scale model representative of GE-F404 nozzles. Configurations consisting of single and dual arrays of MVGs were tested for pressure ratios relevant to takeoff operating conditions. A combination of laboratory measurements and large-eddy simulations are used. Particle image velocimetry reveals that MVGs placed inside the nozzle form oblique shocks that interact with the jet plume's shock cell structure and greatly modify the shock-cell structure issued from the nozzle throat. This modification can weaken the jet plume shock-cell structure and even reduce the jet core velocities. Convective velocities estimated from the high-speed Schlieren imaging showed a significant reduction in magnitude caused by MVGs. When compared to the baseline design, the MVG nozzles showed noise reduction up to 10 dB in the upstream direction and near 5 dB in the peak downstream radiation angle at cold jet conditions. Near-field acoustic measurements showed a significant reduction of low-frequency turbulent mixing noise. Scaling analysis showed that MVGs are capable of delivering the same noise reduction performance across different model scales.