Search

Miniaturized light-emitting diodes (mini-LEDs) have gained much attention for liquid crystal displays back-light and self-emissive displays. However, the unsatisfactory performance of InGaN long-wavelength mini-LEDs hinders their practical applications. Herein, we develop a full-angle distributed Bragg reflector (DBR) and investigate its impact on the performance of yellow flip-chip mini-LEDs. The full-angle DBR consists of different stacks of Ti3O5/SiO2 layers that are optimized for multiple central wavelengths. Compared to conventional single-DBR stacks, such full-angle DBR enables wider reflectance bandwidth and less dependence of reflectance on the light incident angle from 0° to 50°. Specifically, full-angle DBR features high reflectance beyond 99% from 447 to 580 nm at an incident angle of 50°. Full-angle DBR is found to enhance the electric field intensity at the top of devices, indicating that light extraction efficiency is promoted. As a result, yellow flip-chip mini-LEDs with full-angle DBR show higher light output power than those without DBR at the same currents. Our work paves a way to improve the performance of small-size emitters with long wavelength. [ABSTRACT FROM AUTHOR]

Hydrogen will play a key part in the decarbonization of the global energy supply as the wealth of hydrogen continues to rise. However, applying hydrogen knowledge necessitates the installation of strong safety protocols, including the use of reliable hydrogen gas-detecting devices. Gas detection and monitoring at a large scale in industries need programmable electronic systems that can provide fast response and switching. The objective of the research work is to analyze the hydrogen gas detection system using a field programmable gate array (FPGA). The system is integrated with the gas sensor module, temperature control module, buzzer for alarm, liquid crystal display (LCD) and light-emitting diode (LED) for information display, and global system for mobile communication (GSM) for wireless message communication to the mobile. The temperatures module works on the sampling of the heater resistance using a voltage divider and inbuilt analog-to-digital converter (ADC), which depend on the output voltage of the digital-to-analog converter (DAC). The comparator module compares the gas concentration with the pre-decided threshold limit and acknowledges the buzzer accordingly. The system behavior for monitoring and gas concentration detection is simulated in Xilinx Vivado design suite 2020.1. The functionality of the chip is also verified in the Modelsim 10.0 waveform simulator. for the testbench tata sand samples used. LCD (16x2) displays the messages whether hydrogen gas is detected or not and the same message is delivered on mobile. The novelty of the work is that the system is applicable for faster switching in industrial applications and the designed system supported 550 MHz frequency in our simulation and synthesis. [Display omitted] • Hydrogen gas detection and monitoring using FPGA for programmable electronic device switching. • Integration of gas sensor, temperature sensor, alarm, LCD, and GSM wireless communication. • Supports 550 MHz frequency for fast switching operations. • Chip assessment for hydrogen leakage identification, and validation on FPGA hardware. [ABSTRACT FROM AUTHOR]

The enhancement of display performance and durability in polymer-stabilized vertical alignment liquid crystal and the liquid crystal are negative liquid crystals, which can be vertically aligned under the action of a vertical orientation layer and an electric field. Devices (PSVA LCDs) are crucial for advancing LCD technology. This study aims to investigate the electro-optical characteristics of PSVA LCDs by varying polymerization monomer concentrations. Using both simulations via TechWiz LCD 3D and experimental methods, such as polymer-induced phase separation, we developed an optoelectronic testing framework to assess voltage transmittance and response times. In our main findings, we show that an increase in polymeric monomer concentration from 3% to 7% resulted in a 67% increase in threshold voltage and a 44% decrease in saturation voltage. The on-state response time increased by about a factor of three, while the off-state response time decreased by about a factor of three. The alignment of our simulation results with experimental data validates our methodology, offering the potential of simulation tools as a pivotal resource in the PSVA LCDs. The alignment of our simulation results with experimental data validates our methodology, offering the potential of simulation tools as a pivotal resource in the PSVA LCDs. These advancements promise significant improvements in PSVA LCD performance and durability. [ABSTRACT FROM AUTHOR]

This paper proposes a new eye‐tracking data correction method for the development of an automatic detection system for difficult‐to‐read characters in Japanese text. The proposed method, which adjusts the x‐axis of the eye, was compared with existing methods that adjust only the y‐axis. Data correction was performed for each method, and the detection accuracy of difficult‐to‐read Japanese characters was calculated and compared. The experimental results indicate that adjusting the x‐axis and y‐axis can improve the detection accuracy of difficult‐to‐read characters in Japanese text. This research advances easy correction techniques for difficult‐to‐read character detection in Japanese text and broadens the use of eye trackers, including low‐cost eye trackers. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In this study, a novel and sustainable triboelectric material is successfully designed and developed by extracting keratin from recycled fur and combining it with chitosan to create a keratin/chitosan triboelectric nanogenerator (CK‐TENG) device. The device is designed for the simultaneous treatment of waste and the generation of green and clean energy, crucial for addressing global challenges. CK is prepared through a freeze‐drying method to overcome the weak mechanical properties of keratin and achieve a high surface contact area, which is important for triboelectric properties. The results showed that the output voltage is improved by 375% compared to the TENG without keratin, with values reaching 322 V under a 6 N. It produced a high power density of 14.4 W m−2 and excellent cyclic stability for more than 8000 cycles, which are crucial for practical applications. Further, the potential applications are also studied, and the results showed that it can turn on over 250 light‐emitting diodes (LEDs), display liquid crystal display (LCD), and charge capacitors under 6 N. Moreover, it is successful in harvesting energy from waste vibrations, acoustic energy, and as a shoe, and the electrical output is utilized to power electronic devices. Furthermore, the power density harvested by the device is higher than that of TENG devices made with keratin‐rich materials. Therefore, this study paves the way for the use of keratin‐based bio‐waste materials for clean and green energy production, which can play significant roles in applications such as the charging of electronic devices, biomedicine, sensors, and smart textiles. [ABSTRACT FROM AUTHOR]

The fabrication of microfluidic devices has progressed from cleanroom manufacturing to replica molding in polymers, and more recently to direct manufacturing by subtractive (e.g., laser machining) and additive (e.g., 3D printing) techniques, notably digital light processing (DLP) photopolymerization. However, many methods require technical expertise and DLP 3D printers remain expensive at a cost ∼15–30 K USD with ∼8 M pixels that are 25–40 μm in size. Here, we introduce (i) the use of low-cost (∼150–600 USD) liquid crystal display (LCD) photopolymerization 3D printing with ∼8–58 M pixels that are 18–35 μm in size for direct microfluidic device fabrication, and (ii) a poly(ethylene glycol) diacrylate-based ink developed for LCD 3D printing (PLInk). We optimized PLInk for high resolution, fast 3D printing and biocompatibility while considering the illumination inhomogeneity and low power density of LCD 3D printers. We made lateral features as small as 75 μm, 22 μm-thick embedded membranes, and circular channels with a 110 μm radius. We 3D printed microfluidic devices previously manufactured by other methods, including an embedded 3D micromixer, a membrane microvalve, and an autonomous capillaric circuit (CC) deployed for interferon-γ detection with excellent performance (limit of detection: 12 pg mL−1, CV: 6.8%). We made PLInk-based organ-on-a-chip devices in 384-well plate format and produced 3420 individual devices within an 8 h print run. We used the devices to co-culture two spheroids separated by a vascular barrier over 5 days and observed endothelial sprouting, cellular reorganization, and migration. LCD 3D printing together with tailored inks pave the way for democratizing access to high-resolution manufacturing of ready-to-use microfluidic and organ-on-a-chip devices by anyone, anywhere. [ABSTRACT FROM AUTHOR]

The research of narrow band green emitter with excellent luminescent property is regarded as a very significant innovation direction for light-emitting diodes (LED) backlights in liquid crystal displays (LCDs). Herein, a high-efficiency near-ultraviolet (n-UV) excitation Mn2+ doped green phosphor NaGa 11 O 17 : Mn2+ phosphor is obtained based on the strong charge transfer absorption located in the n-UV region. The optimal sample exhibits a high color purity green light emission(≈89.7%) centered at 505 nm with a full width at half maximum (FWHM) around 29 nm. The absorption efficiency (AE), internal quantum efficiency (IQE) and external quantum efficiency (EQE) of optimal sample are 69.8%, 80.4% and 56.1%, respectively. In addition, the doping of Al3+ significantly improves the thermal stability (26.9%–80.1% at 150 °C) by enhancing the electron recombination process. Using NGO: Mn2+ and commercial β-sialon:Eu2+ dual green phosphors as green component fabricated with BAM: Eu2+, KSF: Mn4+ and 310 nm LED chips shows a wide color gamut of 125% NTSC. These findings suggest that our material may find use in LED backlights for liquid crystal displays and provide a meaningful reference for the development of new narrowband emitters. A high-efficiency near-ultraviolet excited narrow-band emission phosphor NGAO:Mn2+ is achieved via a strong charge transfer absorption for wide color gamut WLED application. [Display omitted] [ABSTRACT FROM AUTHOR]

This article discusses a new method for synthesizing benzo[b]carbazoles, which are compounds with various applications in medicinal chemistry and materials science. The researchers also explored the liquid crystalline properties of these compounds and successfully achieved a rare nematic phase at room temperature. By fusing a benzene ring and tethering two alkoxyphenyl units, they were able to stabilize the nematic phase. The degree of order in the liquid crystals was influenced by the length of the alkyl chains. This research highlights the significance of innovative molecular designs in creating functional materials. [Extracted from the article]

The present work aimed to prepare novel bio-based composites by adding fillers coming from agro-wastes to an acrylate epoxidized soybean oil (AESO) resin, using liquid crystal display (LCD) 3D printing. Different photocurable formulations were prepared by varying the reactive diluents, iso-bornyl methacrylate (IBOMA) and tetrahydrofurfuryl acrylate (THFA). Then, two fillers derived from different industrial wastes, corn (GTF) and wine (WPL-CF) by-products, were added to the AESO-based formulations to develop polymer composites with improved properties. The printability by LCD of the photocurable formulations was widely studied. Bio-based objects with different geometries were realized, showing printing accuracy, layer adhesion, and accurate details. The thermo-mechanical and mechanical properties of the 3D-printed composites were tested by TGA, DMA, and tensile tests. The results revealed that the agro-wastes' addition led to a remarkable increase in the elastic modulus, tensile strength, and glass transition temperature in the glassy state for the systems containing IBOMA and for flexible structures in the rubbery region for systems containing THFA. AESO-based polymers demonstrated tunable properties, varying from rigid to flexible, in the presence of different diluents and biofillers. This finding paves the way for the use of this kind of composite in applications, such as biomedical for the realization of prostheses. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) technology has recently seen increased utilization due to its versatility in using functional materials, offering a new pathway for next-generation conformal electronics in the smart sensor field. However, the limited availability of polymer-based ultraviolet (UV)-curable materials with enhanced piezoelectric properties necessitates the development of a tailorable process suitable for 3D printing. This paper investigates the structural, thermal, rheological, mechanical, and piezoelectric properties of a newly developed sensor resin material. The polymer resin is based on polyvinylidene fluoride (PVDF) as a matrix, mixed with constituents enabling UV curability, and boron nitride nanotubes (BNNTs) are added to form a nanocomposite resin. The results demonstrate the successful micro-scale printability of the developed polymer and nanocomposite resins using a liquid crystal display (LCD)-based 3D printer. Additionally, incorporating BNNTs into the polymer matrix enhanced the piezoelectric properties, with an increase in the voltage response by up to 50.13%. This work provides new insights for the development of 3D printable flexible sensor devices and energy harvesting systems. [ABSTRACT FROM AUTHOR]

In this paper, a novel partial scan Gate Driver on Array (GOA) architecture with gate and cascade scan separated output (GCSS‐GOA) is proposed. Combined with a newly designed timing controller (TCON) IC and IP, dynamic local refresh at any position and with different refresh rate at different area on liquid crystal display (LCD) panel are achieved. The driving schemes for dynamic local refresh and the display image quality evaluation results are also presented. For power consumption, it can be reduced by up to 50% respectively for GOA and data drivers in dynamic local refresh mode under 60 Hz benchmark refresh rate. This technology is also applicable to OLED, LED, e‐paper and other display products. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrated the front NFC card swipe and touch display in Touch and Display Driver Integration (TDDI) liquid crystal display (LCD) through the technologies shown later. A new NFC sampling and noise reduction algorithm was used to reduce the generation of the ghost position and touch failure. The touch/NFC part‐time driving was applied to optimize the noise interference when NFC works. Meanwhile, we integrated the NFC antenna in the TDDI LCD and added a new display signal filter circuit and VCOM driver signal. In the NFC in‐cell demo, front NFC swiping distance of 60 mm is achieved. [ABSTRACT FROM AUTHOR]

The conditions for the growth of polycrystalline GeSn films on SiO2/Si(001) substrates by hot wire chemical vapor deposition are determined for the first time. The effect of the introduction of Sn into the Ge lattice on the morphology, structure, and transport properties of films is studied. GeSn films obtained at 300 °C have a uniform surface with a roughness of less than 1.0 nm. It is shown that the introduction of 5% Sn allows, without the use of recrystallization annealing, to significantly increase the hole mobility of polycrystalline GeSn films from 20 to 60 cm2 V−1 × s−1. despite the small grain size of 35 nm. Such films are of great interest for creating thin‐film transistors for active matrices' liquid crystal displays. [ABSTRACT FROM AUTHOR]

The full‐screen mobile phone can be fabricated by integrating the camera beneath the screen, which needs the nanocomposite light guide plate (nano‐LGP) with exceptional transparency and light‐guiding properties simultaneously. Choosing an appropriate nanoparticle with a high refractive index and exceptional compatibility within the polymer matrix is crucial for producing the nano‐LGP. In this study, the high refractive index carbonized polymer dots (HRI‐CPDs) are synthesized through the solvothermal treatment, achieving a refractive index value of 1.7220 at 450 nm. Subsequently, the modified HRI‐CPDs (mHRI‐CPDs)/polymethyl methacrylate (PMMA) nanocomposites are fabricated by copolymerizing the mHRI‐CPDs with methyl methacrylate. Due to the high visible light transmittance and Rayleigh scattering characteristics when light passes through the nanocomposites, this kind of nanocomposites is suitable for serving as nano‐LGPs. The potential of carbonized polymer dots as light‐scattering unit is originally explored to improve surface illuminance and uniformity of nano‐LGPs. The best‐performing 4.3‐inch LGP with 1.0 wt.% doping content shows 15.8 times higher surface illuminance and 2.1 times higher uniformity than pure PMMA. This new type of LGP based on mHRI‐CPDs/PMMA nanocomposite holds tremendous promise in conjunction with advanced liquid crystal display technology. [ABSTRACT FROM AUTHOR]

We develop a measurement and evaluation system to quantify the halo effect of mini‐light‐emitting diode (LED) backlight liquid crystal displays (mLCDs). The validity and reliability of our halo measurement system was investigated through a human visual perception experiment. The results indicate that our halo measurement system can effectively distinguish the halo differences among different displays, with matching rate of 93.3% between our measurement and the human visual system. [ABSTRACT FROM AUTHOR]

Liquid crystal display (LCD)-based 3D printing, a precise and surface-smooth technology, has found widespread use in dentistry due to its exceptional precision and surface quality. This research endeavors to create a scaffold through 3D printing using bone graft materials, specifically addressing the challenge of molding bone graft powders to fit defect areas in dental surgery. Our approach involved developing biphasic calcium phosphate (BCP) scaffolds by regulating the sintering temperature of an HA-based green body. Initially, by using wet ball mill technology, HA slurries with 30 %, 40 %, and 50 % HA content by weight were prepared and exhibited viscosities below 0.15 Pa s. Subsequently, these slurries were 3D printed via an LCD-based VP printer. The utilization of submicron-sized HA particles played a critical role in maintaining slurry stability and preventing sedimentation during the printing process. We investigated sintering temperatures of 1100 °C, 1200 °C, and 1300 °C, discovering that submicron-sized HA particles enabled precise alignment of the decomposition temperature with the typical HA sintering range. Consequently, we achieved the production of BCP scaffolds with adjustable properties by tuning the sintering temperature. Subsequent analysis delved into scaffold shrinkage, mechanical characteristics, degradation behavior, and biological responses. Among the sintered scaffolds, the 50 % HA slurry printed and sintered at 1200 °C exhibited the highest compressive strength. The cell viabilities of these sintered scaffolds consistently met the ISO 10993-5 standard, affirming their biocompatibility. Moreover, the biological responses of MG63 cells demonstrated that the sintered scaffolds not only exhibited cytocompatibility but also facilitated strong cell attachment and proliferation. Furthermore, scaffolds sintered at 1300 °C containing TCP showed the formation of a layer of HA with plate-like structures due to ion-induced precipitation, indicating their bioactivity. In conclusion, this study highlights the promising potential of LCD-based VP 3D printing technology for ceramic slurries, with clear implications for clinical applications in bone tissue engineering. [ABSTRACT FROM AUTHOR]

We have derived formulation and evaluation of polarization-modulated triple-view information display with three TN-LCD layers. The proposed display is composed of three liquid–crystal display (LCD) panels that are placed at a certain gap between polarizers. The viewed image is generated after polarization modulations by the three LCD panels. The polarization modulated results depend on the view directions. Thus, information of three binary images is shared between the displayed images on the three LCD panels. [ABSTRACT FROM AUTHOR]

A virtual qualification (VQ) model is proposed using a digital twin not only for verifying electrical properties of a liquid crystal display (LCD) but also for assessing the effect of environmental stresses. The digital twin is developed to reflect product specifications and distributions of manufacturing process data. The VQ model utilizes the digital twin to infer and verify the changes in electrical characteristic values in the internal circuit under a high‐temperature operating test. Additionally, a procedure is proposed for developing digital twins, and its effectiveness is demonstrated based on a case study of an LCD. The developed digital twin may also be used for similar LCD models for design verification. [ABSTRACT FROM AUTHOR]

Lopsided Schumpeterian competition and the emergence of 'superstar' firms are examined in the flat-panel display industry, where the difficulty of commercialising active-matrix OLED (AMOLED) flat panels led to patterns of innovation and competition vastly dissimilar to those that had prevailed in Liquid Crystal Display (LCD) flat panels. Applying the concept of a Schumpeterian 'Ultra-Mark II' technological regime, the study sheds light on how superstar firms build industry dominance through R&D and the building of exclusive supplier networks when their industry (or a certain segment of it) morphs into a quasi-monopolistic type of arena. [ABSTRACT FROM AUTHOR]

Downconverters, primarily inorganic phosphors, are critical components in white solid-state LED-based lighting and liquid crystal display backlights. Research efforts have led to a fundamental understanding of a downconverter's absorption, photoluminescence, and efficiency as a function of composition, structure, and processing conditions. However, considerably less work has focused on the reliability of phosphors once they are incorporated into LED packages. Solving these issues is often the final step before the commercialization of new materials, but the significant resources and time required to evaluate and mitigate materials failure are rarely discussed in the literature. In this Perspective, we discuss the need for conducting downconverter reliability testing and the potential of accelerating, screening, and understanding downconverter failure modes. Our focus highlights the mechanisms of failure and discusses how this influences materials selection and the design of different LED packages. We also stress the potential for accelerated reliability testing protocols and note the potential role first-principles calculations and data-driven models could play in establishing the compositional-processing trends for different aspects of downconverter reliability. We close with possible research directions that could improve downconverter reliability and emphasize the importance of assessing a material's (chemical) stability where multiple manufacturing and processing steps can dictate system performance. [ABSTRACT FROM AUTHOR]

Global energy policies have urged power consumption reductions for electronic devices. However, this is inconsistent with the users' need for enhanced device performance. In this work, converse flexoelectricity is used to reduce power consumption while maintaining the superior display image quality of liquid crystal display (LCD). The first 1 Hz‐refresh‐rate and flicker‐free fringe‐field switching (FFS) LCD for a 13.4‐inch laptop are reported. A noticeable brightness deviation is inevitable when driving voltage polarity is altered during low‐frequency driving, which is caused by the flexoelectric effect and voltage‐holding failure. The nature of the converse flexoelectric contribution of mesogenic systems with the optimum flexoelectric coefficients and molecular polarity, and developed materials based on findings is investigated. The quality of static images and videos at 1‐ and 10 Hz refresh rates, respectively, is maintained, and the measured power consumptions are reduced by 83% and 47% compared to that at a 60 Hz refresh rate, and minimal flicker level is measured by −68 dB. It is believed that this will serve as a new paradigm for energy consumption in electronic devices with superior display performance of FFS LCDs. [ABSTRACT FROM AUTHOR]

A rapid checkerboard pattern change is used to elicit pattern-reversal visual evoked potentials (PR VEPs). CRT or LCD monitors do not allow immediate reversal of the entire pattern. The study aimed to construct a new stimulator whose characteristics approximate an instantaneous reversal and verify whether the improvement is reflected in PR VEPs. A new stimulator using a matrix of 12 × 48 independent white square LEDs was designed and compared with LCDs and CRTs. The effect on the PR VEP peak times and amplitudes of N70, P100, and P140 waves was evaluated in ten subjects. The LED stimulator showed significantly better performance in the rate of change of illuminance, change of pattern, luminance settling and stability. The PR VEP amplitudes of N75, P100, and N140 did not show significant differences. The sum of interpeak amplitudes was significantly larger for the LCD than for the other monitors. The peak times of the waves evoked by the LED were shorter than those evoked by the LCD and CRT for the N75 wave and a check size of 30´. LED stimulators are a better alternative to CRTs for PR VEPs than current LCDs. LEDs also seem to be better than CRTs, but further research is necessary to obtain significant results. [ABSTRACT FROM AUTHOR]

In this comprehensive review, the current state of the art and recent advances in 3D printing in dentistry are explored. This article provides an overview of the fundamental principles of 3D printing with a focus on vat photopolymerization (VP), the most commonly used technological principle in dental practice, which includes SLA, DLP, and LCD (or mSLA) technologies. The advantages, disadvantages, and shortcomings of these technologies are also discussed. This article delves into the key stages of the dental 3D printing process, from computer-aided design (CAD) to postprocessing, emphasizing the importance of postrinsing and postcuring to ensure the biocompatibility of custom-made medical devices. Legal considerations and regulatory obligations related to the production of custom medical devices through 3D printing are also addressed. This article serves as a valuable resource for dental practitioners, researchers, and health care professionals interested in applying this innovative technology in clinical practice. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the thermal properties of epoxy–acrylate blends for the liquid crystal display (LCD) 3D printing technique. Starting from an epoxy–acrylate blend with a ratio of epoxy to acrylate of 50:50, the effect of adding a reactive monofunctional epoxy diluent was evaluated. The diluent was a resin composed by oxirane, mono[(C12-14 alkyl) methyl] derivatives selected for its low viscosity (i.e., 1.8 Poise) at room temperature and its reactivity. The diluent content varied from 15 to 25 wt% and, for all the formulation, double curing cycles, where thermal curing followed photocuring, were studied. The effect of different curing temperatures was also evaluated. The control of the diluent content and of the curing temperature allowed tailoring of the thermomechanical resin properties while improving the resin's processability. The glass transition ranged from 115.4 °C to 90.8 °C depending on the combination of diluent content and post-curing temperature. The resin developed displayed a faster processing time tested on a reference part with printing time of 4 h and 20 min that was much lower than the printing times (7 and 16 h) observed for the starting formulations. [ABSTRACT FROM AUTHOR]

This article focuses on generation of diffractive optical elements (DOEs) and computer holograms for forming three-dimensional (3D) images. We intend to analyze the possibilities of increasing (1) the speed of generation of DOEs, and (2) the quality of 3D objects created by the DOEs generated. For this, four methods of optical element generation are analyzed, which are based on division of 3D objects into plane layers. We assess the quality of 3D-object image reconstruction and the resource intensity of the methods with respect to synthesis of DOEs. We conduct a computer simulation of reconstruction of images of 3D objects via the generated DOEs. In optical experiments on formation of 3D objects, the DOEs generated are displayed on a liquid crystal spatial light modulator. We experimentally establish that the method of parallel computation of plane layers and the method of nonconvex optimization are optimum for formation of 3D objects vis-à-vis quality of their reconstruction. Taking into account the computational resource intensity of the considered methods, the iterative method of parallel computation of plane layers yielded the optimal DOE generation results in terms of reconstruction quality-to-synthesis speed ratio. The possibility of fast formation of high-quality 3D objects comprising dozens of layers has been demonstrated, which can be used in high-resolution 3D video communication systems. [ABSTRACT FROM AUTHOR]

This study proposes a general strategy for constructing an asymmetric Fabry–Perot structure based on an ultra‐thin composite absorber, Ni/Ge2Sb2Se4Te1, to produce reflective full‐color structural colors with high brightness and purity. The composite absorber effectively enhances the strong interference effect of thin film, which can significantly reduce the reflection bandwidth of the target band and the reflectivity of the non‐target band. Under the premise of optimizing the five‐layer base structure, full‐color structural colors can be tuned by only changing the thickness of the LaTiO3 layer. Using the ion‐assisted electron beam evaporation technique, a simple and efficient film deposition process, six color devices (namely red, orange, yellow, green, blue, and purple) are successfully prepared with reflection peaks exceeding 90%. The chromaticity coordinates of the proposed high‐purity red, green, and blue (RGB) samples are (0.554, 0.339), (0.280, 0.600), and (0.164, 0.075), respectively. These coordinates are fairly close to the standard RGB color coordinates used in liquid crystal displays. This device has a simple structure with a novel material combination and a low production cost, which makes it feasible for mass production using just one coating run process. It has excellent application potential in various fields such as micro‐nano displays, anti‐counterfeiting measures, reflective color filters, and decorations. [ABSTRACT FROM AUTHOR]

Biomass‐based hydrogel is a promising flame‐retardant material and has a high potential for applications in transportation, aerospace, building and electrical engineering, and electronics. However, rapid vat photopolymerization (VP) 3D printing of biomass‐based hydrogels, especially that of all‐natural ones, is still rare. Herein, a new class of VP 3D‐printed hydrogels with strong covalent networks, fabricating using fully biomass materials and a commercial liquid crystal display (LCD) printer assembled with low‐intensity visible light is presented. Encouragingly, the highly ordered layer‐by‐layer packing structures provided by VP 3D printing technology endow these hydrogels with remarkable flame retardancy, exceptional temperature resistance, advantageous combustion behaviors, and favorable mechanical strength, in particular, giving them a better limit oxygen index (83.5%) than various biomass‐based hydrogels. The proposed approach enables the green design as well as the precise and efficient preparation for flame‐retardant materials, paving the way for the future flame‐retardant materials toward attaining green sustainability. [ABSTRACT FROM AUTHOR]

Robust amorphous glass protected CsPbBr3 (CsPbBr3@glass) perovskite quantum dots (PeQDs) with ultra‐pure green emission and superior long‐term stability are highly desirable for developing wide‐color‐gamut liquid crystal displays. However, most of the reported CsPbBr3@glass nanocomposites are subject to low external quantum efficiency (EQE). This work demonstrates that ZrO2 additive has an "accumulation" effect on the borosilicate glass network structure to promote in situ nucleation/growth of PeQDs inside glass rather than self‐crystallization. This effect is beneficial in reducing surface defects, improving the quality of PeQDs, and thus boosting radiative recombination of excitons. As a consequence, the as‐prepared CsPbBr3@glass shows a record EQE of up to 75% and can pass the accelerated aging tests at 85 °C/85% RH for 1000 h and blue light irradiation over 2000 h. Finally, a prototype display using CsPbBr3@glass‐based straight‐down backlit unit is designed and gains more favorable responses in blind selection tests for its high brightness of 2647 cd m−2 and high color purity of 88%. The findings will pave the way for realizing the commercial application of CsPbBr3@glass nanocomposite in PeQDs‐converted backlit display. [ABSTRACT FROM AUTHOR]

Vertically Aligned mode Liquid Crystal Displays (VALCDs) which have generated huge research interest due to their excellent contrast and wide viewing angle require materials with negative dielectric anisotropy. This work highlights the systematic development of a fifteen-component mixture from pure liquid crystalline compounds comprising laterally fluorinated bi-, tri- phenyl, tolane, bicyclohexane compounds and non-mesogenic compounds exhibiting negative dielectric anisotropy. The temperature dependence of birefringence (Δn), dielectric anisotropy (Δε), threshold voltage (Vth), bend elastic constant (K33), relaxation time (τ0) and rotational viscosity (γ1) as a function of temperature of this fifteen-component nematic mixture have been reported. This mixture exhibits a high Figure of Merit (FoM) which is desirable for reducing the device response time. Additionally, the orientational order parameter (OOP) values, activation energy (Ea), visco-elastic co-efficient (γ1/K33) and material parameters (A0) have also been reported. The effect of pretilt angle in the alignment layers on the threshold voltage (Vth) and switching time (τ0) to ascertain the applicability of this material in Vertically Aligned mode Liquid Crystal Displays (VALCDs) have also been discussed. [ABSTRACT FROM AUTHOR]

In the semiconductor and liquid crystal display (LCD) industries, suspended ceilings are widely used in wafer and LCD panel fabrication plants (fabs). Despite several preventive measures having been taken, substantial financial losses have been incurred in past earthquakes, with one of the main causes attributed to damage or collapse of ceilings due to excessive ceiling sway during earthquakes. A practical approach of incorporating customised viscous dampers into suspended ceilings to mitigate their seismic response is described in this article. Unlike the convention in most fabs, where diagonal bracing rods are added between suspended ceilings and the structural floor slab to mitigate ceiling vibration, this new approach installs customised viscous dampers in between the ceiling and the column/wall. An analytical model to simulate the vibration of a suspended ceiling was developed. Shake table tests of the ceiling–structure model were then conducted to verify the effectiveness and feasibility of the proposed approach. The results indicated that, when equipped with viscous dampers, the displacement responses of a suspended ceiling can be significantly reduced. Incorporating the dampers into the ceiling with added bracing rods was found to give the best seismic performance. [ABSTRACT FROM AUTHOR]

Sucker-rod deep-well pumping units widely used in oil production are described. It is shown that oil production depends on the operating conditions of these units, which are selected based on the results of analyzing closed dynamometer charts. The latter describe the load on the suspension depending on the stroke of the polished rod of the unit. The quality of preparing the charts determines the ability to diagnose the technical condition of the unit. The trends in the development of existing dynamometer systems and methods for diagnosing the condition of a sucker-rod deep-well pumping unit have been analyzed. One of the ways to create an intelligent intertraverse dynamograph is considered based on a messdose of a pocket dynamograph with the use of modern pressure, acceleration, and temperature sensors; STM32 controllers; a graphic liquid crystal display with an I2C interface; radio communication protocols and digital technologies for processing periodic sensor signals. The existing dynamometer systems along with force and stroke sensors installed in various unit locations were analyzed, and the possibility of developing an intelligent stationary dynamograph by utilizing the latest advances in the field of technology and equipment for analyzing noises of the measured signals has been demonstrated. The proposed dynamograph should ensure early diagnostics of the technical condition of the unit, while satisfying the following criteria: low cost; ease of assembly; high sensitivity, reliability, flexibility, and accuracy. A block diagram of an intelligent intertraverse dynamograph for a sucker-rod deep-well pumping unit is presented, which is based on a pocket dynamograph messdose. The proposed intelligent intertraverse dynamograph will be useful for early diagnostics of the technical condition of deep-well pumps and tubing strings connecting them with the ground equipment, which will ultimately contribute to improving reliability of oil production equipment. The proposed intelligent intertraverse dynamograph can also be used in other engineering fields, where there is a need to measure force. [ABSTRACT FROM AUTHOR]

The utility of visible light for 3D printing has increased in recent years owing to its accessibility and reduced materials interactions, such as scattering and absorption/degradation, relative to traditional UV light‐based processes. However, photosystems that react efficiently with visible light often require multiple molecular components and have strong and diverse absorption profiles, increasing the complexity of formulation and printing optimization. Herein, a streamlined method to select and optimize visible light 3D printing conditions is described. First, green light liquid crystal display (LCD) 3D printing using a novel resin is optimized through traditional empirical methods, which involves resin component selection, spectroscopic characterization, time‐intensive 3D printing under several different conditions, and measurements of dimensional accuracy for each printed object. Subsequent analytical quantification of dynamic photon absorption during green light polymerizations unveils relationships to cure depth that enables facile resin and 3D printing optimization using a model that is a modification to the Jacob's equation traditionally used for stereolithographic 3D printing. The approach and model are then validated using a distinct green light‐activated resin for two types of projection‐based 3D printing. [ABSTRACT FROM AUTHOR]

Stereolithography (SLA) additive manufacturing is a method of manufacturing capable of generating complex geometric shapes with extremely high accuracy. Classic SLA uses UV curable resins, particularly polylactic acid (PLA), for part generation, but recent research has focused on utilizing this technology for the generation of various composite materials. There has been success in manufacturing composite materials using this technology, but little research has been performed on the generation of carbon-fiber-reinforced composite materials. Carbon fiber stereolithography (CF-SLA) is often overlooked due to carbon fiber's natural inability to bond with PLA. To overcome this boundary, surface modification techniques were used on chopped carbon fibers to achieve greater bonding. Here, two modification techniques were explored: a sodium dodecyl sulfate (SDS) surfactant addition and nitric acid (HNO3) etching. These methods were used to functionalize and prepare the surface of chopped carbon fiber (CF) for bonding with cured PLA resin. Treated fibers were dispersed in generic PLA resin, and tensile test specimens were printed for examining the reinforcement potential of the two treatment methods. Additional complexities arise during printing with fibers including fiber alignment, accumulation, and fiber fallout. To address these issues, a novel in-process mixing method was developed to maintain fiber dispersion. A two-level three-factor factorial design was performed for both treatment methods to determine optimal printing parameters. Through mechanical testing, atomic force microscopy, scanning electron microscopy, and contact angle measurements, the accompanying material property changes were characterized to further develop the field of fiber-reinforced liquid crystal display (LCD) additive manufacturing. After testing, it was found that composites created with SDS nanoparticle modification were stronger than both the acid etched fiber sample and plain PLA. Specifically, SDS surface treatment resulted in a 15% increase in modulus and maximum strength of the sample, mainly by enhancing the interlayer bonding between CF and PLA. [ABSTRACT FROM AUTHOR]

The polarizer film is an important component in the Thin-film-transistor liquid crystal displays (TFT-LCDs), which is a multilayer composite film developed by using dichromatic material stretching film technology. However, the polarizer film is liable to fail in hygrothermal circumstances. In this work, we analyzed a polarizer film shipped from China to Brazil that failed due to the ocean environment. By analyzing the structure, composition, and crystallinity of the polarizer film, Polyvinyl Alcohol (PVA) layer of the polarizer film has larger crystallinity, and there are bonding pores between the PVA layer and the Triacetyl Cellulose (TAC) layer. Under the action of the marine environment, the I3− ions in the PVA layer were released, resulting in the separation of PVA layer and TAC layer at the bonding pores, and then forming bright spots. Furthermore, through analyzing the marine environment and simulated environmental experiments, it was determined that the thermal environmental factor induces the release of I3− ions in the PVA layer. Finally, based on the failure process and failure mechanism of the polarizer, improvement measures to prevent the occurrence of bright spots of the polarizer are proposed. [ABSTRACT FROM AUTHOR]

The seeded growth method offers an efficient way to design core–shell semiconductor nanocrystals in the liquid phase. The combination of seed and shell materials offers wide tunability of morphologies and photophysical properties. Also, semiconductor nanorods (NRs) exhibit unique polarized luminescence which can potentially break the theoretical limit of external quantum efficiency in light emitting diodes based on spherical quantum dots. Although rod‐in‐rod core–shell NRs present higher degree of polarization, most studies have focused on dot‐in‐rod core–shell NRs due to the difficulties in achieving uniform NR seeds. Here, this study prepares high‐quality uniform CdSe NRs by improving the reactivity of the Se source, using a secondary phosphine, namely diphenylphosphine, to dissolve the Se power, along with the conventional tertiary phosphine, namely trioctylphosphine. Starting from these high‐quality NR seeds, this study synthesizes CdSe/CdxZn1−xS/ZnS core–shell NRs with narrow emission bandwidth (29 nm at 620 nm), high PLQY (89%) and high linear polarization (p = 0.90). This study then assembles these core–shell NRs using the confined assembly method and fabricates long‐range‐ordered microarrays with programmable patterns and displaying highly polarized emission (p = 0.80). This study highlights the great potential of NRs for application in liquid crystal displays and full‐color light emitting diodes displays. [ABSTRACT FROM AUTHOR]

This study investigated the accuracy and stability of accommodative and vergence functions in children with and without hyperopia while engaged in two sustained near tasks. The sustained accommodative and vergence characteristics of participants without refractive correction (n = 92, aged 5–10 years) with and without hyperopia (defined as cycloplegic retinoscopy ≥ + 1.00D and less than + 5.00D) were measured using eccentric infrared photorefraction (PowerRef 3; PlusOptix, Germany). Binocular measures of accommodation and eye position were recorded while participants engaged in 2 tasks at 25 cm for 15 min each: (1) reading small print on an Amazon Kindle and (2) watching an animated movie on liquid crystal display screen. Comprehensive visual assessment, including measurement of presenting visual acuity, amplitude of accommodation, and stereoacuity was conducted. The magnitude of accommodative and vergence responses was not related to refractive error (P > 0.05). However, there were inter-task differences in the accuracy and stability of the accommodative responses across refractive groups (P < 0.05). The relationship between accommodation and vergence was not significant in both tasks (P > 0.05). However, increased accommodative and vergence instabilities were associated with total accommodative response (P < 0.05). Despite having greater accommodative demand, uncorrected hyperopes accommodate comparably to emmetropic controls. However, uncorrected hyperopes have increased instabilities in their accommodative and vergence responses, which may adversely impact their visual experience. [ABSTRACT FROM AUTHOR]

We present the first eight months of data from our secondary target programme within the ongoing Dark Energy Spectroscopic Instrument (DESI) survey. Our programme uses a mid-infrared and optical colour selection to preferentially target dust-reddened quasi-stellar objects (QSOs) that would have otherwise been missed by the nominal DESI QSO selection. So far, we have obtained optical spectra for 3038 candidates, of which ∼70 per cent of the high-quality objects (those with robust redshifts) are visually confirmed to be Type 1 QSOs, consistent with the expected fraction from the main DESI QSO survey. By fitting a dust-reddened blue QSO composite to the QSO spectra, we find they are well-fitted by a normal QSO with up to AV  ∼ 4 mag of line-of-sight dust extinction. Utilizing radio data from the LOFAR Two-metre Sky Survey (LoTSS) DR2, we identify a striking positive relationship between the amount of line-of-sight dust extinction towards a QSO and the radio detection fraction, that is not driven by radio-loud systems, redshift and/or luminosity effects. This demonstrates an intrinsic connection between dust reddening and the production of radio emission in QSOs, whereby the radio emission is most likely due to low-powered jets or winds/outflows causing shocks in a dusty environment. On the basis of this evidence, we suggest that red QSOs may represent a transitional 'blow-out' phase in the evolution of QSOs, where winds and outflows evacuate the dust and gas to reveal an unobscured blue QSO. [ABSTRACT FROM AUTHOR]

Blue phase liquid crystals (BPLCs) have significant potential in the field of liquid crystal displays (LCDs) and are proposed as potential next-generation of LCDs candidates. However, BPLCs do not emit light directly and need an extra backlight device. As a result, the blue phase liquid crystal display retains the disadvantages of low brightness and low energy efficiency, which remarkably limit its application. Recently, as a kind of novel fluorescent carbon nanomaterials, carbon dots (CDs) have captured considerable attention because of their excellent optical properties. Here, CDs were directly synthesized by a simple solvothermal method and introduced into BPLCs. By combining the excellent optical properties of CDs with the blue phase liquid crystal system, the photoluminescent blue phase liquid crystals (CDs-BPLCs) with self-photoluminescence are prepared. Meanwhile, the stability of BPLCs can be improved by CDs. Such CDs-BPLCs have enormous potential in the development of novel energy-saving display devices. [ABSTRACT FROM AUTHOR]

The unintentional electromagnetic radiation of digital electronic devices during operation can cause information leakage and threaten the information security of the system. In order to explore the leakage level of important information, it is necessary to separate the electromagnetic leakage signal from the complex environmental electromagnetic wave, so the blind source separation technology is studied.Traditional blind source separation methods are mainly unsupervised learning methods, and their separation results are not as expected. In recent years, deep learning technology based on supervised learning has achieved good results in speech separation and other fields, indicating that it is a feasible method.In order to solve the problem of separating source signals from mixed electromagnetic radiation signals and reducing noise interference in electromagnetic safety detection. this paper proposes a Deep Focusing U-Net neural network, which makes the model pay more attention to the features at deeper layer. The network is applied to the blind separation of LCD electromagnetic leakage signals, and the good separation performance proves the effectiveness of this method. [ABSTRACT FROM AUTHOR]

High dynamic range (HDR) displays based on liquid crystal panels require local dimming algorithms to reproduce content with high fidelity and HDR. However, most local dimming algorithms are developed by using hand-crafted features and most of them focus on low dynamic range images rather than HDR images. In addition, few local dimming algorithms can manage well the conflicting requirements of maintaining image quality while minimising power consumption. In this paper, we propose a genetic algorithm for backlight local dimming (GABLD) that generates images for the HDR display based on the given fitness function and the HDR content about to be displayed while considering the impact of power consumption and image quality. The effectiveness of the GABLD method is demonstrated in three aspects: the fidelity of reconstruction of HDR images, the power consumption, and the visualisation of HDR content on HDR displays. The results show that the proposed method has good performance in terms of both the image quality and power consumption, and it retains more details especially for areas with highlights when compared to traditional methods. [ABSTRACT FROM AUTHOR]

Linear codes with complementary duals (shortly named LCD codes) are linear codes whose intersection with their duals are trivial. In this paper, we give a method of constructing these type of linear codes from equitable partitions of association schemes. The LCD codes constructed in this paper are of length 2n and dimension n and have the property of being formally self-dual. To illustrate the method we construct LCD codes from some distance-regular graphs. [ABSTRACT FROM AUTHOR]

The nematic phase of the bent-core family proves to be particularly fascinating due to its distinct properties in comparison to its calamitic counterpart. Here we revealed after the dispersion of semiconducting CdS QD an achiral unsymmetrical (4′-fluoro phenyl azo) phenyl-4-yl 3-[N-(4′-n-hecyloxy two hydroxybenzylidene)amino]-2-methylbenzoate (6-2M-F) a bent-core nematic (BCN) liquid-crystalline medium made of bent-shaped molecules with short cores and low bend angles. These molecules are on the cusp between conventional bent-core molecules and rod-like molecules, with characteristics somewhere in between, resembling hockey sticks. The threshold voltage (V th) , dielectric permittivity (ε ‖ , ε ⊥) , and elastic constants (K 33 , K 11) of pure BCN have been considerably influenced by semiconductor nanoparticles. The threshold voltage (V th) of nano-disperse BCN has decreased with QD doping, and we know that the low operation voltage is one of the key considerations in the development of mobile liquid crystal display technology. Similar to other BCNs with smectic-like clusters previously described, the elastic anisotropy (Δ K = K 33 − K 11) for 6-2M-F is negative; however, the insertion of CdS QDs causes the anisotropy to become very positive (bend elastic constant (K 33) > splay elastic constant (K 11)). While the parallel component of permittivity (ε ‖) has declined with doping, the perpendicular component of permittivity (ε ⊥) has increased, leading to a considerable reduction in dielectric anisotropy (Δ ε = ε ‖ − ε ⊥) in the nanocomposite, which implies the effect on nematic ordering due to the interaction between CdS QDs and the LC molecules. [ABSTRACT FROM AUTHOR]

We proposed a polarisation interference filter (PIF) to enlarge the colour gamut of liquid crystal display (LCD) with YAG-LED backlight, and the PIF consists of two crossed polarisers and two liquid crystal layers. The PIF can be used in the backlight unit to improve the colour gamut of LCD by eliminating unwanted colours in the spectrum. When the PIF is integrated into the YAG-LED backlight, the colour gamut of the LCD can be improved from 84% NTSC to 116% NTSC, and the colour gamut is larger than 116% NTSC within 30° polar angle. When a compensation layer is employed, the colour gamut distribution of LCD is more uniform at full viewing angles. The PIF has great potential for achieving a wide colour gamut display. [ABSTRACT FROM AUTHOR]

This review summarizes the self-assembly of block molecules forming unconventional two-dimensional (2D) periodic nanopatterns. Especially, we emphasize the structural evolution from simple columnar phases to complex 2D tiling morphologies in soft materials including block copolymers, liquid crystals, giant molecules, etc. Then, the state-of-the-art nanofabrication technologies for making sophisticated nanostructures with specific functions via combining both bottom-up assembly and top-down lithography-based methods are discussed, highlighting the use of directed self-assembly processes. Finally, we provide our perspective on this area. By further increasing the complexity of block molecules and the designability of lithography, low-dimensional ordered morphologies will be particularly promising for further application in nanotechnology. [ABSTRACT FROM AUTHOR]

A low-power long-term ambulatory ECG monitor was developed for the acquisition, storage and processing of three simultaneous leads DI, aVF and V2 with a beat-to-beat heart rate measurement in real time. It provides long-term continuous ECG recordings until 84 h. The monitor uses a QRS complex detection algorithm based on the continuous wavelet transform with splines, which automatically selects the scale for the analysis of ECG records with different sampling frequencies. It includes a lead-off detection to continuously monitor the electrode connections and a real-time system of visual and acoustic alarms to alert users of abnormal conditions in its operation. The monitor presented is based in an ADS1294 analogue front end with four channels, 24-bit analog-to-digital converters and programmable gain amplifiers, a low-power dual-core ESP32 microcontroller, a microSD memory for data storage in a range of 4 GB to 32 GB and a 1.4 in thin-film transistor liquid crystal display (LCD) variant with a resolution of 128 × 128 pixels. It has programmable sampling rates of 250, 500 and 1000 Hz; a bandwidth of 0 Hz to 50% of the selected sampling rate; a CMRR of −105 dB; an input margin of ±2.4 V; a resolution of 286 nV; and a current consumption of 50 mA for an average battery life of 84 h. The ambulatory ECG monitor was evaluated with the commercial data-acquisition system BIOPAC MP36 and its module for ECG LABEL SS2LB, simultaneously comparing the morphologies of two ECG records and obtaining a correlation of 91.78%. For the QRS detection in real time, the implemented algorithm had an error less than 5%. The developed ambulatory ECG monitor can be used for the analysis of the dynamics of the heart rate variability in long-term ECG records and for the development of one's own databases of ECG recordings of normal subjects and patients with cardiovascular and noncardiovascular diseases. [ABSTRACT FROM AUTHOR]