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Paper‐based analytical devices as a low‐cost and point‐of‐care sensing platform have attracted widespread research interest. However, the device fabrication and signal readout remain a challenge for their real‐world applications. Herein, a technically simple paper‐based sensor is developed by taking advantage of the easily accessible paper and the plasmonic property of gold nanomaterials. The sensing mechanism relies on the iodide‐mediated surface etching of gold nanostars that induces a color change from blue to red of the paper strip. The versatility of the paper substrate in size, shape, and materials allows for the facile immobilization of gold nanostars by a simple immersing method, which is easy to operate and free from specialized skills and equipment. In addition, the readout of the paper strip can be conveniently visualized by the naked eye or through a smartphone. This paper‐based sensor advantages in low cost, light weight, easy handling, and disposability that holds great promise as a point‐of‐care detection platform in resource‐constrained settings. [ABSTRACT FROM AUTHOR]

Miniaturized paper‐based electrochemical sensors were fabricated using kraft paper and CO2 laser, dispensing the need for chemical reagents and controlled atmospheric conditions. This study initially evaluated the paper type and laser processing parameters, enhancing the electrodes′ robustness, electrochemical response, and electrical resistance. The sensors were also treated by applying −1 V for 60 s in 1.0 mol L−1 KCl, which is a simple and rapid procedure. The electrochemical treatment increased the electroactive area and roughness, confirmed by scanning electron microscopy. These aspects helped modulate the sensors′ electrochemical response for nitrite determination, improving selectivity and sensitivity for this compound. The sensors also showed repeatability and batch‐to‐batch reproducibility, with 2.2 and 10 % RSD, respectively. Therefore, this work brings a protocol to fabricating competitive electrochemical sensors through a sustainable strategy, opening possibilities for designing new analytical systems. [ABSTRACT FROM AUTHOR]

Two imidazole‐based color‐changing fluorescent probes 4‐(4,5‐bis(4‐chlorophenyl)‐1H‐imidazol‐2‐yl)‐N, N‐diphenylaniline (CIN) and 4‐(4,5‐di(furan‐2‐yl)‐1H‐imidazol‐2‐yl)‐N, N‐diphenylaniline (FIN) were synthesized and characterized. The new probes CIN and FIN exhibit excellent selectivity and sensitivity towards Fe3+ with relatively low detection limits (0.26 μM and 0.10 μM) and strong anti‐interference properties. Both the probes CIN and FIN complex 1 : 1 with Fe3+ ion, and the complexation constants were 1.165×105 M−1 (CIN) and 1.899×105 M−1 (FIN), respectively. Moreover, CIN and FIN could be recycled by EDTA and could effectively monitor Fe3+ ions at pH 4–10, which ensures the sensor's potential for detecting Fe3+ in actual aqueous solutions. The probes were further applied to the detection of Fe3+ in the actual reaction of Fe2+ oxidation, and the filter paper and the probe solution are combined to make an indicator to detect Fe3+ more conveniently and quickly. [ABSTRACT FROM AUTHOR]

Food is necessary for survival, and contamination can shorten humans' lives on Earth in all dimensions. Real‐time screening of food pollutants, such as toxins, infectious agents, and chemical contaminants, is in high demand today. Thus, a cost‐effective and ecologically benign technology must be developed to detect food contamination in a rapid fashion. Nanoparticle (NP)‐based paper sensors are one of the most important alternatives to traditional methods because these are simple, inexpensive, highly selective, and sensitive tools. This article provides an overview of NP‐based paper sensor techniques for detecting toxic food contaminants. [ABSTRACT FROM AUTHOR]

Paper has been extensively accepted as an ideal platform for fabricating low‐cost, flexible, and environmentally friendly electronics. However, current paper‐based pressure sensors have not fully demonstrated the unique merits of paper, such as cost efficiency, disposability, cuttability, and foldability, mainly because of the limitation of the applied metal electrodes and device configuration. Here, an all‐organic, all‐paper, cuttable, and foldable pressure sensor is demonstrated for the first time, with the high‐conductivity polypyrrole (PPy) printing paper as electrode and the low‐conductivity PPy tissue paper as active layer. Hollow and 3D all‐paper sensors are realized through fabricating the kirigami or origami structure since the device can be freely cut and folded, presenting a universal strategy promising for flexible device design. The cuttability and foldability of device create a unique 3D perception capability. The devices show high sensitivity (4.8 kPa−1 at < 5.5 kPa, 1.7 kPa−1 at 5.5–40 kPa) and wide detection range (up to 40 kPa), providing a capability for full‐range detection of human physiological and motion signals. These results open a feasible route to realize hollow and 3D sensors and fully demonstrate the potential of paper sensors for diverse applications to new‐generation green electronics and portable electronics. [ABSTRACT FROM AUTHOR]

Paper‐based surface‐enhanced Raman spectroscopy (SERS) sensors can be fabricated easily by dropcasting or inkjet printing colloidal Au nanoparticles onto cellulose‐based filter papers. They are flexible, economical, and sensitive and provide the crucial advantage of point‐of‐need sampling for application in the field. In this study, paper‐based SERS sensors are fabricated through inkjet printing of a colloidal Au sol onto a filter paper substrate. We have characterized their SERS performances with benzenethiol and pyridine molecules using a handheld Raman analyzer. Due to the heterogeneous loading of the Au nanoclusters on the paper substrate, we introduce the concept of receiver operating characteristic as an alternate measurand to quantify the performance of these sensors. With their inherent filtration sampling capability, we demonstrate the use of paper SERS sensors for the detection of chemical aerosols. Lastly, we present the use of a precision materials printer to deposit quantifiable amounts of analyte (fentanyl) uniformly across the active sensing area of a paper SERS sensor. This will allow for analyte‐loaded certified references to be prepared and used in the field as standards for comparison. [ABSTRACT FROM AUTHOR]

Real‐time and continuous monitoring of ultraviolet (UV) radiation in daily activity is critical in diverse fields ranging from personal fitness, cosmetics, to medical aspects. Here, a wearable UV monitoring patch that can be easily fixed/removed at desired locations and provide real‐time and continuous UVA levels in daily life is developed. The wearable patch consists of a highly sensitive, flexible graphene sensor for UVA measurement and a multifunctional fabric patch integrated with commercial electronic components for signal processing, wireless transmission. To achieve a high sensitive UVA sensor with high flexibility and long‐term stability, porous reduced graphene oxide (pRGO) papers are fabricated by simple solvent evaporation followed by thermochemical reduction. The flexible UVA sensors based on pRGO papers feature a high UVA photoresponsivity of 125 mA W−1, which is comparable to that of a commercial silicon‐based UV sensor. Furthermore, the polydimethylsiloxane‐encapsulated pRGO (PDMS‐pRGO) sensors exhibit stable UVA photoresponse characteristics that is maintained under severe conditions, such as a large number of bending cycles, thermal heating, and high humidity. The use of wearable patches that enable real‐time, wireless monitoring of personal UVA levels in various practical applications are demonstrated. [ABSTRACT FROM AUTHOR]

The separation efficiency of charge carriers determines the analytical sensitivity of the paper-based photoelectrochemical sensor. Herein, the Lewis base modification strategy is proposed to promote the carrier separation through an in-situ ion exchange method. Firstly, three-dimensional paper-based hierarchically TiO2 (PHT) arrays are prepared with the one-step hydrothermal method. With the aid of Lewis base, the photoinduced charge separation efficiency and the photocurrent signal are obviously increased. Ultimately, sensitive sensing of prostate specific antigen (PSA) is achieved and the linear range is 1 pg/mL-100 ng/mL with the detection limitation of 0.3 pg/mL. [ABSTRACT FROM AUTHOR]

2D palladium nanostructures enable sensitive room‐temperature detection of H2. However, they can be limited by stability and fabrication costs. Stability may be improved by alloying Pd with other metals, while cost could be reduced by using paper as a substrate. An ultra‐low‐cost sensor using Pd alloy (PdMoY) nanosheets (NS) on paper is reported. The 2D Pd alloy nanosheets are prepared by a solution‐phase route, drop cast onto paper (≈1 × 1 cm) with silver contacts drawn on it, and dried. The same material is deposited on an interdigitated electrode (IDE). Both sensors are tested for response to hydrogen in air. The resistance of the paper‐based sensor decreased by ≈18.7% in 1% H2, which is about 40 times the response of the IDE‐based sensor. Its H2 limit of detection (1 ppm) is also lower than that of the IDE‐based sensor (5 ppm). Compared to pristine Pd NS, PdMoY NS are more stable to repeated H2 pulses without any signs of buckling or cracks. The nanosheets are also deposited by inkjet printing to produce functional sensors, providing a simple route to manufacturing of ultra‐low‐cost gas sensors for use in fuel‐cell vehicles and related infrastructure. [ABSTRACT FROM AUTHOR]

How to monitor the freshness of packaged food, the safety of sealed medicine, or the other substances in sealed space wirelessly and environment‐friendly has become an urgent problem in recent years. After summarizing the theory of the LC sensor, a design of a paper‐based resonator (30 mm × 30 mm × 0.15 mm) consisting of a finger capacitor is proposed in this paper. The sensor is embedded inside the package by adhering it to the package's inner wall. Its response is remotely detected through a readout coil. This paper establishes a circuit simulation model and an electromagnetic simulation model to verify the feasibility of the design. Compared with the real object and the theoretical simulation model, the difference between the results only within 1 MHz, which verifies the correctness of the theory. Additionally, the measured results indicate that the resonant frequency of the resonator shifted from 102.441 MHz to 88.195 MHz, after dropping water on the sensor. Besides, the simple fabrication technology and inexpensive sensor material ensure a low cost, thus making this technology economically viable. [ABSTRACT FROM AUTHOR]

Different on‐chip antennas in Complementary Metal‐Oxide‐Semiconductor (CMOS) technology for THz detector and source are proposed. Firstly, the size of these antennas is estimated with an equivalent CMOS substrate model. Finally, through electromagnetic simulation, the structure optimised and slotted the on‐chip antenna to realise multi‐band detection, miniaturised detection, and miniaturised source. For the THz detector, multi‐band antennas with a dual‐ring structure and miniaturised antennas with circular and diamond structures are designed. At the frequency of 300, 600, and 800 GHz, the gain of the ring antennas is 5.7, 7.2, and 7.2 dBi, respectively. The gain of the circular and diamond antenna is 5.3 and 5.96 dBi at 300 GHz. For the THz source, rectangular‐slot and T‐slot antennas are designed at the frequency of 300 GHz and the gain of the rectangular‐slot and T‐slot antennas is 2.92 and 3.87 dBi, respectively. Multi‐band antennas and miniaturised antennas effectively save the occupation area and improve the performance of the THz system. The effectiveness of antennas is verified by the measurement of the detector and the source, which indicates that the proposed on‐chip antennas have potential prospects for CMOS THz applications. [ABSTRACT FROM AUTHOR]

Nanocomposite enzymes are attracting intensive attention worldwide. In the present study, a novel colorimetric H2O2 paper sensor was developed based on a new type of nanocomposites composed of Pd−Pt nanoparticles, hemin functionalized reduced graphene oxide (hemin‐rGO) and carboxylated carbon nanotubes (CNTs‐COOH). The proposed nanocomposites show a high peroxidase‐like activity. It provides a sensitive platform showing a linear response toward H2O2 in the range of 0.05–500 μM with a determination limit of 0.01 μM. Based on this, the composites were applied to construct a paper sensor for H2O2 detection in real samples. The cost‐effectiveness, simplicity and efficiency of this paper sensor could be developed for "point‐of‐care" analysis and other related areas. [ABSTRACT FROM AUTHOR]

Porous graphene (PG) devices fabricated in situ from polyimide (PI) adhered onto paper substrates provide a cost‐effective and recycling‐friendly alternative to re‐engineer paper for liquid‐based power sources and sensors. However, paper is generally damaged due to heating during the fabrication of PG devices. Here integrated graphene‐paper electronics with exceptional thermal control through the proposed thermally localized laser graphitization (LLG) process is demonstrated, employing optimized ultrafast laser writing. LLG enables in situ fabrication of localized porous graphene (LPG) devices (>1775 K) on 65 µm thick PI tape adhered to paper without heating above 348 K. Laser parameters for LLG are predicted using an analytical temperature model and validated experimentally. The LLG is demonstrated by fabricating liquid electrolyte LPG micro‐supercapacitors and humidity sensors on liquid susceptible paper. It is envisaged that the scientific concepts proposed and demonstrated here will expedite the development of low‐cost, scalable, and chemically robust LPG devices on thermally sensitive substrates. [ABSTRACT FROM AUTHOR]

As a self‐emissive technology, microLED displays retain all benefits of OLEDs and should be able to improve on many aspects, but will it be enough to guaranty success? In February 2024, leading proponent Apple canceled its microLED smartwatch project. More generally, as microLED keeps getting delayed and OLED keeps improving, the value proposition of microLED is shrinking. This paper looks at how the technology could deliver stronger differentiation. [ABSTRACT FROM AUTHOR]

Mercury ions are highly toxic at trace levels, and its pollution has posed a significant threat to the environment and public health, where current detection methods mainly require laborious operation and expensive instrumentation. Herein, a simple, cost‐effective, instrument‐free approach for selective detection of Hg2+ based on a hand‐drawn paper‐based naked‐eye colorimetric device is developed. To develop a hand‐drawn paper‐based device, a crayon is used to build hydrophobic barriers and a paper puncher is applied to obtain patterns as a sensing zone. A green method for the synthesis of silver nanoparticles (AgNPs) is applied using Achillea Wilhelmsii (Aw) extract. The sensing ability of Aw‐AgNPs toward Hg2+ is investigated in both solution‐phase and paper substrate loaded with Aw‐AgNPs using colorimetric methods. For the paper‐based sensor, the quantification of the target relies on the visual readout of a color‐changed sensing zone modified with Aw‐AgNPs. Under optimal conditions, the color of Aw‐AgNPs in aqueous solution and on the coated paper substrate can change from brown to colorless upon addition of target, with a detection limit of 28 × 10−9m and 0.30 × 10−6m, respectively. In conclusion, the present study indicates the potential of this hand‐drawn eco‐friendly paper‐based sensor for monitoring of mercury. [ABSTRACT FROM AUTHOR]

The use of paper‐based devices in combination with noninstrumental detection systems is becoming increasingly important in the analytical field due to its simplicity, rapidity, and low cost. However, their use for determination of volatile analyte derivatives is still relatively scarce. The present work reports on the assessment of a paper‐based gas‐sensing approach for the simultaneous noninstrumental colorimetric detection of nitrite and sulfide. Colorimetric systems based on the Griess and methylene blue assays, formation of colored metallic sulfides, and interaction/reaction with in situ generated metallic nanoparticles were preliminary evaluated. Then, the effect of experimental variables affecting the analytical performance of the paper‐based gas sensor was studied with two digitization systems, namely a scanner and a smartphone. Under optimal conditions, the developed system yielded limits of detection of 0.055 and 0.005 mg/L for nitrite and sulfide, respectively. The repeatability, expressed as relative standard deviation, was found to be 5.9 and 6.7% for nitrite and sulfide, respectively. The proposed method was finally applied to the analysis of water samples, showing recoveries in the range of 95–105%. [ABSTRACT FROM AUTHOR]

Paper‐based advanced functional materials have become the focus of intense research in recent years. Particularly, magnetic papers show strong potential for applications in a wide range of 4.0 technologies including communication, magnetic sensing, electromagnetic filtering, magnetic‐based health care tools, point‐of‐care microfluidic devices, and security. In situ and lumen‐loading, the main methods to prepare magnetoactive papers, have problems such as the rigorous reaction conditions, hard control of deposition location, decreased tensile strength, poor retention of magnetic nanoparticles, or the obligation to perform the magnetic impregnation during the papermaking process, that hinder their applicability. Those issues are addressed in the present work, in which ≈20 nm Fe3O4 nanoparticles are hydrothermally synthesized and later incorporated in a wax‐based home‐made cartridge and nanoimpregnated into paper by a thermal process leading to a magnetic paper with improved stress and strain at rupture and Young's modulus, 30 MPa, 4.5%, and 2 GPa, respectively, when compared to neat paper, 15 MPa, 3.5%, and ≈1 GPa, respectively. Additionally, the reported magnetic impregnation method provides the paper with a 0.2 emu g–1 magnetic saturation, allowing it to work as a bending actuator with a bending of 12 mm at an applied magnetic field of 105 mT. [ABSTRACT FROM AUTHOR]

Fabriano paper was aged by irradiation with ultraviolet light (λ=310) in a veterometer for 300 hours. At fixed time intervals, samples of the paper under test were analysed by titanium dioxide photosensor to determine electrochemically the ‘environmental persistence’ index, by a suitable conductimeter method, to determine the specific conductivity variation and by thermogravimetry to determine the moisture content, the onset temperature of the cellulose degradation process and the value of the activation energy of the same process. The behaviour of these different types of indicators displayed approximately monotonous trends as a function of time. [ABSTRACT FROM AUTHOR]

A paper‐based potentiometric sensor was constructed and characterized for the detection of glucose in saliva. Dilution of the samples was optimized to afford the optimum experimental conditions of measurements. The performance allows for detecting abnormal high glucose concentrations observed in diabetes patients. Repeatability data were presented and the performance of the sensor compared to literature examples showing suitable characteristics at a much lower cost. The validation in real saliva samples was performed against a commercial colorimetric kit showing that glucose could be effectively determined in the 4–10 mM range based on the comparison with a reference method. [ABSTRACT FROM AUTHOR]

There is a growing interest in developing displays with additional functions. We propose new microLED display architectures embedding Vis/NIR/SWIR emission/sensing. In the first, addressing full‐screen fingerprint application, there is no tradeoff between sensor performance and display brightness. In the second, related to near‐field touchless display application, the proposed solution reduced significantly the complexity. [ABSTRACT FROM AUTHOR]

We developed a flexible imager comprising low‐temperature polycrystalline silicon thin‐film transistors and organic photodiodes. The developed flexible imager has high‐resolution and high‐speed readout characteristics. Owing to these characteristics, pulse wave signals can be measured, and the images of fingerprints and veins can be obtained. Furthermore, we developed three‐axis tactile pressure sensors by integrating flexible optical components. The sensors can detect both normal and tangential pressures. [ABSTRACT FROM AUTHOR]

This work describes a terbium luminescence‐based protocol to selectively detect gallate‐derived green tea polyphenols on a supramolecular gel immobilised paper platform for the first time. This user‐friendly, inexpensive (€ 0.0015) approach requires very low sample volumes for the analysis. The developed strategy enables simultaneous detection of gallate polyphenols in multiple tea samples with the potential for practical applications. [ABSTRACT FROM AUTHOR]

A new, simple and low‐cost method for patterning hydrophobic barriers in porous support such as paper by Parafilm® has been introduced. This method is then used for electrochemical paper‐based ammonia sensor construction. Ammonia sensor is based on electrochemical concentration cell which ammonia reaction with electrolyte in halves cell caused in concentration gradient and therefore potential difference dependent on ammonia concentration. The effect of concentrations of the involved chemicals, time periods of the required processes, the presence of Faraday cage as well as the effects of different salts used in the salt bridge on the response of the sensor, were investigated in order to find the optimized conditions. [ABSTRACT FROM AUTHOR]

Herein, we present the first paper‐based device for facing one of the worldwide concerns of the Modern age: the corrosion‐induced deterioration of reinforced concrete. Indeed, the monitoring of corrosion extent in reinforced concrete constructions has been acknowledged as a priority for public safety. In this work, the porosity properties of a paper‐based screen‐printed Ag/AgCl electrode were exploited for realising a smart analytical tool to be directly applied on the solid surface of concrete for the evaluation of corrosion. The analysis was carried out by measuring the electrochemical potential between the metallic reinforcement and the sensor, needing only 70 μL of electrolyte solution. The sensor was firstly tested in the laboratory using reinforced concrete samples and then applied on the real outdoor artwork Music Collection Session by Arman (Milan, Italy). A summary of the main available non‐destructive techniques for corrosion monitoring is reported to provide a critic overview. [ABSTRACT FROM AUTHOR]

In some previous research studies, quite successful results have been obtained in using online tools to increase students' academic achievement. In many fields; the benefits of online formative quizzes have been widely recognized by educators. However, there is little research determining whether weekly formative online exams affect students' academic achievement, especially in engineering courses. In this quasi‐experimental study, it was investigated whether the weekly quiz application method had an effect on students' academic achievement in an engineering course. One hundred and ninety sophomores participated in the study. Although the experimental group (n = 81) used the quizzes prepared on the Course Portal online to learn the Sensors and Transducers Unit, the control group (n = 109) solved the quizzes in the textbook on a paper‐pencil basis. After the online quizzes were solved, the experimental group was given which questions they answered incorrectly and the related video link of these incorrectly answered questions, and the relevant section of the book was given by the Course Portal as feedback. The pretest and posttest data of the students were obtained, and analysis of covariance was utilized as the analysis method to reveal the answer to the study question. The statistical analysis of the students' average achievement scores in the posttest (midterm exam) showed that the experimental group's average achievement score was significantly better than the control group. Results show that online weekly exams have significant effects on students' academic achievement. Weekly online quizzes are recommended to engineering lecturers as they offer students to improve their students' academic success. [ABSTRACT FROM AUTHOR]

This study investigates the use of 10‐(4‐butoxyphenyl)‐10H‐phenothiazine (PTZ), a phenothiazine‐based molecule, for detecting chloroform and other chlorinated hydrocarbons (CHCs). Upon exposure to these compounds to the phenothiazine‐dervitive in presence light, a significant change in emission occurs, enabling naked‐eye detection. The visual detection range of this phenothiazine derivative extends down to concentrations as low as 5 ppm. We demonstrate the one‐time use of thin‐layer chromatography paper (TLC) sensors and glass‐based sensors for on‐site detection of chlorinated hydrocarbons using a light source such as sunlight, UV‐lamp, or a solar box. Our findings suggest that this phenothiazine‐derivative has potential as a simple, low‐cost, and effective sensing platform for chlorinated solvents, with practical applications in environmental monitoring and industrial safety. Furthermore, our results provide insights into the development of molecular sensors for detecting chlorinated hydrocarbons. [ABSTRACT FROM AUTHOR]

The reliable detection of pathogenic bacteria in complex biological samples using simple assays or devices remains a major challenge. Herein, we report a simple colorimetric paper device capable of providing specific and sensitive detection of Helicobacter pylori (H. pylori), a pathogen strongly linked to gastric carcinoma, gastric ulcers, and duodenal ulcers, in stool samples. The sensor molecule, an RNA‐cleaving DNAzyme obtained through in vitro selection, is activated by a protein biomarker from H. pylori. The colorimetric paper sensor, designed on the basis of the RNA‐cleaving property of the DNAzyme, is capable of sensitive detection of H. pylori in human stool samples with minimal sample processing and provides results in minutes. It remains fully functional under storage at ambient temperature for at least 130 days. This work lays a foundation for developing DNAzyme‐enabled paper‐based point‐of‐care diagnostic devices for monitoring pathogens in complex samples. [ABSTRACT FROM AUTHOR]

The paper presents the smart FRP composite bridge panel called „OptiDeck" with integrated distributed fibre optic sensors (DFOS), to monitor the panel's behavior. The panel is intended for use in newly build and refurbished road bridges. From structure point of view the uniqueness of the presented solution results from innovative technological production process to create a honeycomb core in thick sandwich panel. In order for the monitoring system to cover the entire surface of the panel and to detect local damage, it was necessary to use a modern solution based on geometrically continuous DFOS system. The DFOS system serves as the structure health monitoring (SHM) system, which has been tested during the production and laboratory testing of a prototypes in natural scale. The advantages of DFOS measurements are well known and applied in many civil engineering applications. However, the potential benefits are still not fully utilized. Finally the experimental verification of the DFOS system integrated with the FRP deck panel is presented. [ABSTRACT FROM AUTHOR]

Paper‐based superomniphobic surfaces are of great interest because paper is flexible, inexpensive, lightweight, breathable, and recyclable. Prior reports on paper‐based superomniphobic surfaces have failed to demonstrate high mobility with low surface tension liquids. In order to overcome this issue, in this work, superomniphobic papers are developed through growth of nanofilaments on inherent microfibers of papers without noticeably altering their microscale features (i.e., diameter and distance of the microfibers). These superomniphobic papers display very low roll‐off angle, indicative of ultra‐high droplet mobility, even with low surface tension liquids. Here, a facile method is also developed to control the motion and adhesion of the droplets on the superomniphobic paper. Utilizing such liquid mobility in a controlled manner on these superomniphobic papers, a simple on‐paper pH sensor is fabricated. It is anticipated that this on‐paper, simple, and rapid detection methodology can also be extended to the colorimetric sensing of protein and chemical assays. Further, these superomniphobic papers have potential applications in water–oil separation and enhanced weight‐bearing capacity. [ABSTRACT FROM AUTHOR]

With the advent of µLED displays, multiple paradigm shifts in the overall system architecture will offer new opportunities and dramatically change the requirements of display management and general sensing. This work focuses on the required system architecture of a microLED display with embedded sensing functionality. [ABSTRACT FROM AUTHOR]

The integration of fully printed transistors on low cost paper substrates compatible with roll-to-roll processes is demonstrated here. Printed electronics promises to enable a range of technologies on paper including printed sensors, RF tags, and displays. However, progress has been slow due to the paper roughness and ink absorption. This is solved here by employing gravure printing to print local smoothing pads that also act as an absorption barrier. This innovative local smoothing process retains desirable paper properties such as foldability, breathability, and biodegradability outside of electronically active areas. Atomic force microscopy measurements show significant improvements in roughness. The polymer ink and printing parameters are optimized to minimize ink absorption and printing artifacts when printing the smoothing layer. Organic thin film transistors (OTFT) are fabricated on top of this locally smoothed paper. OTFTs exhibit performance on par with previously reported printed transistors on plastic utilizing the same materials system (pBTTT semiconductor, poly-4-vinylphenol dielectric). OTFTs deliver saturation mobility approaching 0.1 cm2V-1s-1 and on-off-ratio of 3.2 × 104. This attests to the quality of the local smoothing, and points to a promising path for realizing electronics on paper. [ABSTRACT FROM AUTHOR]

Accumulation of high concentrations of Al(III) in body has a direct impact on health and therefore, the trace detection of Al(III) has been a matter for substantial concern. An anionic metal organic framework ({[Me2NH2]0.5[Co(DATRz)0.5(NH2BDC)] ⋅ xG}n; 1; HDATRz=3,5‐diamino‐1,2,4‐triazole, H2NH2‐BDC=2‐amino‐1,4‐benzenedicarboxylic acid, G=guest molecule) composed of two types of secondary building units (SBU) and channels of varying sizes was synthesized by employing a rational design mixed ligand synthesis approach. Free −NH2 groups on both the ligands are immobilized onto the pore surface of the MOF which acts as a superior luminescent sensor for turn‐on Al(III) detection. Furthermore, the large channels could allow the counter‐ions to pass through and get exchanged to selectively detect Al(III) in presence of other seventeen metal ions with magnificent luminescence enhancement. The observed limit of detection is as low as 17.5 ppb, which is the lowest among the MOF‐based sensors achieved so far. To make this detection approach simple, portable and economic, we demonstrate MOF filter paper test for real time naked eye observation. [ABSTRACT FROM AUTHOR]

We evaluate and compare the performance of a 15.6‐inch mini‐LED backlit LCD (mLCD) with a commercial OLED panel. Results show that the mLCD exhibits advantages over the OLED panel in peak brightness, gamma curve, color volume, power consumption, and ambient contrast ratio. The LMK imaging photometer with a high‐resolution CMOS sensor is employed to characterize the halo effect and reconstruct the real luminance profiles based on the non‐ideal profile of the OLED display. We have also proposed a novel strategy to measure the backlight's point spread function. [ABSTRACT FROM AUTHOR]

A novel emissive Schiff‐base (3)has been synthesized through single‐step condensation of sulfanilamide and fluorogenic 3‐formylchromone. Compound (3) senses Fe3+ ion in semi‐aqueous media. Both fluorogenic and colorimetrical changes were observed in the presence of Fe3+ ions. Interestingly, on introduction of EDTA into the putative complex, [(3)+Fe3+], the spectroscopic changes were reversed. The ligand detects Fe3+ ions sensitively as the limit of detection for Fe3+ ion was 9.3×10−7 M. The probe performs molecular logic operation (INHIBIT) as well as function of a three‐input keypad lock. Further, the ligand (3)was successfully incorporated into Whatman filter paper as the test strips and aluminium coated silica gel plates, which showed a great selectivity for Fe3+ ions. [ABSTRACT FROM AUTHOR]

Current methods of monitoring breathing require cumbersome, inconvenient, and often expensive devices; this requirement sets practical limitations on the frequency and duration of measurements. This article describes a paper-based moisture sensor that uses the hygroscopic character of paper (i.e. the ability of paper to adsorb water reversibly from the surrounding environment) to measure patterns and rate of respiration by converting the changes in humidity caused by cycles of inhalation and exhalation to electrical signals. The changing level of humidity that occurs in a cycle causes a corresponding change in the ionic conductivity of the sensor, which can be measured electrically. By combining the paper sensor with conventional electronics, data concerning respiration can be transmitted to a nearby smartphone or tablet computer for post-processing, and subsequently to a cloud server. This means of sensing provides a new, practical method of recording and analyzing patterns of breathing. [ABSTRACT FROM AUTHOR]

This paper firstly introduces a flexible hybrid integration (FHI) architecture based on organic thin‐film transistors (OTFTs) for ubiquitous sensor systems, followed by description of the low power OTFT technologies. Then, progresses on sensor integration based on the OTFTs for FHI are discussed, proving the versatility of the technology. [ABSTRACT FROM AUTHOR]

A paper-based colorimetric sensor system (PBCSS) was developed to detect the amount of bis(pinacolato)diboron (B2Pin2) and applied as a high-throughput screening protocol in Ir-catalyzed C−H borylation. First, 96 ligands were screened for the borylation of benzene, and then 12 of them were selected and tested for five substrates. These reaction mixtures were spotted in the PBCSS, showing a blue-violet color. The value of the gray scale of each reaction was obtained from these colored spots and converted to the extent of conversion of B2Pin2. The extents of conversion of B2Pin2 obtained from the PBCSS showed good correlation with those obtained from gas chromatography analysis. In addition, the modified conversion using blank data showed good correlation with the yield of products. [ABSTRACT FROM AUTHOR]

The wide range of pressure detection and the exceptional linearity are essential performance parameters for flexible pressure sensors, enabling them to adapt to diverse scenarios and acquire information accurately. However, currently available "ultra‐wide range" piezoresistive sensors lack an optimal solution that effectively balances sensing properties, device thickness, and process cost. This study proposes a distinctive approach by introducing a Janus conductive structure assembled with dual resistive sensitive layers. The design allows for a pressure‐induced staged transformation of the current transport path, effectively mitigating variations and saturation in sensor resistance over a wide pressure range. The resulting piezoresistive sensor demonstrates an unprecedented detection range of 0–3800 kPa, showcasing remarkable sensitivity of 4.11 kPa−1 and outstanding linearity of 99.9% within the range of 0–1000 kPa. Additionally, the sensor boasts a thickness of only ≈200 µm, made possible through the utilization of a cellulose nanofibers material matrix. These performance achievements stand at the forefront when compared to existing reports. This research explores the potential applications of these sensors and extended arrays in the domains of human health and motion monitoring. It investigates their utility in gait analysis for assisted posture correction, as well as in the assessment and rehabilitation of gait instability. [ABSTRACT FROM AUTHOR]

Since OLED was first mass‐produced by Samsung Display, various researches related to OLEDs have been actively conducted and now days, People are using OLED displays every single day. As a next generation organic‐optoelectronic display, we suggest the All‐in‐one Sensor Display which can be used for fingerprint recognition, proximity sensor, illuminance sensing and photoplethysmogram which is an area of rapid interest in recent years. To demonstrate the All‐in‐one Sensor Display in entire display area, in this research, we successfully fabricated organic photodetectors (OPDs) in the OLED panels with our own materials, D‐01 and A‐01. Since designing a donor material and an acceptor material is key issue for high Signal to Noise ratio (SNR), we designed and synthesized the D‐01 and A‐01. With our own material based OPDs, All‐in‐one Sensor Display showed good characteristics and successfully recognized fingerprints. This research shows the possibility of the mass production of next organic diode and we believe that All‐in‐one Sensor Display will be the next display application beyond the OLEDs. [ABSTRACT FROM AUTHOR]

A solution for ambient light sensor (ALS) integration in a‐Si LCD with cost advantage and nearly the same performance as external ALS solution. In this work we provide practical solution for the most challenged smartphone [ABSTRACT FROM AUTHOR]

Paper electronics represents a newly raised concept that includes various types of electronic devices and circuits on paper. In this work, the authors report multigate oxide‐based homojunction electric‐double‐layer thin‐film transistors (TFTs) with cellulose nanofibers electrolyte film as the gate dielectrics on paper substrate. These flexible TFTs exhibit high performance with a high ON/OFF ratio of 107 and a high mobility of around 26 cm2 V−1 s−1. Resistor‐loaded inverters are demonstrated both in a bottom‐gate mode and an in‐plane‐gate mode. Logic AND operation is realized in a device with two in‐plane gates. Significantly, the universal logic NAND is experimentally demonstrated using a one transistor/one resistor structure by combining NOT and AND logics together. The paper‐based TFT devices are very interesting for emerging areas such as disposable paper electronics and sensors. [ABSTRACT FROM AUTHOR]

Rapid, precise, and reproducible deposition of a broad variety of functional materials, including analytical assay reagents and biomolecules, has made inkjet printing an effective tool for the fabrication of microanalytical devices. A ubiquitous office device as simple as a standard desktop printer with its multiple ink cartridges can be used for this purpose. This Review discusses the combination of inkjet printing technology with paper as a printing substrate for the fabrication of microfluidic paper-based analytical devices (μPADs), which have developed into a fast-growing new field in analytical chemistry. After introducing the fundamentals of μPADs and inkjet printing, it touches on topics such as the microfluidic patterning of paper, tailored arrangement of materials, and functionalities achievable exclusively by the inkjet deposition of analytical assay components, before concluding with an outlook on future perspectives. [ABSTRACT FROM AUTHOR]

Quantum dots (QD) have seen a rapid uptake in display applications, especially as photoluminescent color conversion layers. In parallel, QD absorbers promise efficient photodetector components, with absorption peak tunability and monolithic integration. In this paper, we describe QD stack integration into infrared imagers, enabling accessible sensors for various display interfaces. [ABSTRACT FROM AUTHOR]

This paper presents a novel optical type in‐cell fingerprint sensor (iFP) technology, which can detect a user's fingerprint on display. By using low temperature polysilicon (LTPS) TFT process, new sensor material, and active pixel sensor circuit (APS), this sensor can detect a fingerprint image with good performance. The FPS/Touch/Display Driver IC (FTDI) is also implemented in this work, and successfully demonstrated. [ABSTRACT FROM AUTHOR]

The fabrication, characterization, and applications of paper‐based screen‐printed carbon electrodes (SPCE) are discussed. In particular, microscopy images of the working electrode surface show a reproducible 3D pattern that enhances the performance of the device compared to that of a polyester‐based SPCE. Gold nanoparticles and CdSe@ZnS quantum dots are detected using different electrochemical techniques. [ABSTRACT FROM AUTHOR]

A polarization independent refractive index (RI) sensor with a RI sensitivity of 50 nm/RIU is demonstrated. The proposed RI sensor simply consists of a liquid crystal (LC) polymeric polarization grating film and one glass substrate. The wavelength shift over the refractive index of surrounding medium is investigated through anisotropic rigorous coupled‐wave analysis. Such a LC‐based polarization independent RI sensor not only enables the usage of an unpolarized light source but also manifests a high sensitivity, offering great potential for the integration with display systems. [ABSTRACT FROM AUTHOR]

This paper proposes a predictive power control strategy for the three‐phase, six‐switch Vienna rectifier without grid voltage sensors to reduce the hardware cost and complexity of a high‐power PWM rectifier system. Firstly, an algorithm for calculating the AC‐side voltage in the αβ coordinate system is derived according to the operating principle of the Vienna rectifier, and a voltage observer is constructed by combining a second‐order low‐pass filter to estimate the grid voltage. Secondly, a soft start method is designed to solve the problem that the rectifier is prone to inrush current when it is started. Furthermore, the control method of grid voltage sensorless is combined with predictive power control with good dynamic characteristics and simple parameter settings to form the control strategy proposed in this paper. Finally, simulation analysis and experimental verification are carried out on the proposed control strategy. Simulation and experimental results show that the grid voltage estimation has high accuracy, a good surge current suppression effect, unit power factor operation, low input current harmonic content, and good dynamic and steady‐state performance. Therefore, the correctness and effectiveness of the strategy proposed in this paper are verified. [ABSTRACT FROM AUTHOR]

Keywords: electrochemical treatment; laser-pyrolyzed; paper-based devices; paper-based electrodes; nitrite EN electrochemical treatment laser-pyrolyzed paper-based devices paper-based electrodes nitrite 1 1 1 01/06/23 20230102 NES 230102 B The Cover Feature b illustrates eco-friendly laser-pyrolyzed paper sensors used for nitrite determination in environmental and biological samples. Cover Feature: Modulating the Electrochemical Response of Eco-Friendly Laser-Pyrolyzed Paper Sensors Applied to Nitrite Determination (ChemElectroChem 1/2023) Electrochemical treatment, laser-pyrolyzed, paper-based devices, paper-based electrodes, nitrite. [Extracted from the article]

We have developed a nanomesh based on skin sensors that can detect physiological signals such as electrocardiogram (ECG), pressure, and acoustic detection. Nanomesh sensors have high gas permeability and softness. Owing to the high gas permeability, the nanomesh sensor did not cause inflammation when the sensor was attached to the skin for a week. Furthermore, we developed a wireless ECG monitoring system by combining a nanomesh sensor and a textile‐based wireless module. [ABSTRACT FROM AUTHOR]

Solution‐processed organic photodetectors (OPDs) have witnessed great progress in the past few years. With silicon‐like performance achieved, OPDs enable new medical imaging applications by offering cost‐effective light detection over large area. Herein, we illustrate the compelling advantages of high spatial and temporal resolution OPD arrays for medical X‐ray detectors and wearable pulse oximeters. [ABSTRACT FROM AUTHOR]