Technology For Applications Research Articles

Temperature-dependent dielectric properties of the Korean lunar simulant and ilmenite: Lunar microwave processing potential

There is increasing interest in the potential application of microwave sintering technology in the construction of infrastructure on the Moon. This study aimed to characterize the dielectric properties of in situ lunar materials; this information is critical for an understanding of the interaction of these materials with microwave and in the application of microwave sintering technology. Dielectric properties including the real and imaginary permittivity, dielectric loss tangent, penetration depth, and electrical conductivity of Korean Lunar Simulant (KLS-1) and ilmenite (an abundant lunar mineral) were investigated at microwave frequencies as a function of temperature. X-ray dispersion (XRD) analyses confirmed that the lattice expansion of minerals with increasing temperature was consistent with an increasing trend in permittivity. The dielectric loss tangent of ilmenite was 2–36 times higher than that of KLS-1, depending on temperature, indicating that ilmenite has greater ability to absorb microwave energy, converting it to heat. Ilmenite demonstrated rapid heating to 1000°C within a few minutes on exposure to 1 kW microwave (2.45 GHz) irradiation. This study provides important information relevant to the development of microwave technology for future lunar applications.

Experimental demonstration of radius-varying active plasma lensing for laser-plasma-accelerated proton beams with increased collection angle

Active plasma lensing, a compact method for intensifying the focus of charged particle beams by providing a magnetic field gradient of kT/m, has emerged as a sought-after technology in laser plasma accelerator applications. However, the utilization of active plasma lenses faces significant hurdles when dealing with laser-driven proton pulses, characterized by their broad bandwidth and high divergence. To address this challenge, we developed a novel active plasma lens with a variable radius, specifically designed to optimize lens geometry in accordance with the beam envelope, and performed the first measurement of its focusing ability. The experimental findings reveal that, compared to conventional cylindrical active plasma lenses, our radius-varying lens exhibits a 2.0-fold improvement in single-energy transmission efficiency, while maintaining comparable achromatic ability. This breakthrough is anticipated to significantly contribute to the miniaturization of laser proton accelerators. Published by the American Physical Society 2024

Imaging performance of portable and conventional ultrasound imaging technologies for ophthalmic applications.

The aim of this study was to evaluate the imaging capabilities of Butterfly iQ with conventional ophthalmic (piezoelectric) ultrasound (COU) for ophthalmic imaging. Custom phantom molds were designed and imaged with Butterfly iQ and COU to compare spatial resolution capabilities. To evaluate the clinical imaging performance of Butterfly iQ and COU, a survey containing pathological conditions from human subjects, imaged with both Butterfly iQ and COU probes, was given to three retina specialists and graded on image detail, resolution, quality, and diagnostic confidence on a ten-point Likert scale. Kruskal-Wallis analysis was performed for survey responses. Butterfly iQ and COU had comparable capabilities for imaging small axial and lateral phantom features (down to 0.1 mm) of high and low acoustic reflectivity. One of three retina specialists demonstrated a statistically significant preference for COU related to resolution, detail, and diagnostic confidence, but the remaining graders showed no significant preference for Butterfly iQ or COU across all sample images presented. The emergence of portable ultrasound probes offers an affordable alternative to COU technologies with comparable qualitative imaging resolution down to 0.1 mm. These findings suggest the value to further study the use of portable ultrasound systems and their utility in routine eye care.

Movie recommendation and classification system using block chain

Recommender Systems are mainly used in various e-commerce applications, especially online stores threatening users’ privacy. The privacy issues can be overcome by using security solutions, which include blockchain technology for privacy applications. The fusion of the Internet of Things and blockchain technology has fully improved modern distributed systems. The combination guarantees the safety and scalability of the recommender system. We aim to create an authorized secure exchange device using blockchain-enabled multiparty computation by adding smart contracts to the core blockchain protocol. The recommendation structure and Blockchain technology make online shopping more convenient and private. We propose a blockchain-related recommender system using the “movielens” data. The case study includes a smart contract model that recommends movies to buyers. Initially, we tested the model on a small “movielens dataset” and extended it to a 3M movielens dataset. We developed a classifier model for movielens and proposed a Dual light graph convolutional network for movielens data classification. Our results, including ablation analysis, show that blockchain strategies and Dual light graph convolutional networks can effectively improve recommender systems’ privacy. Furthermore, the suggested blockchain technique can be stretched by similar procedures.

Momentum Fourier ptychographic topography

Reflective Fourier Ptychographic Microscopy (FPM) has demonstrated the potential as a technology for semiconductor metrology and inspection applications, offering both a wide field-of-view (FOV) and high resolution with nanoscale height reconstruction accuracy. However, to enhance resolution, the wavelength of the illumination source has been shortened to the ultraviolet (UV) range, leading to a significant decrease in height calculation accuracy due to low signal-to-noise issues. Additionally, the time-consuming aspect persists as a challenge. To address these issues, we introduce Momentum Fourier Ptychographic Topography (MFPT). MFPT can overcome the problem of getting trapped in local minima due to noise, and it does not require an iterative process of total variant regularization, allowing for significant computational time savings. Using UV illumination with MFPT, we measure a United States Air Force (USAF) 1951 target and two step-height samples, providing evidence that MFPT is robust to noise and accurately reconstructs nanoscale height. As a result, utilizing UV illumination with MFPT allows us to achieve a resolution of 173 nm, and we can rapidly and accurately calculate the height of step-height samples with nominal heights of 30 nm and 70 nm.

Sensitivity enhanced flexible capacitive pressure sensor microstructure optimization for biomedical applications

Abstract This paper explores the design and optimization of Flexible Capacitive Pressure Sensors (FCPS) using microfabrication technology for applications in the emerging field of flexible electronics, with a particular focus on measuring bio-signals characterized by lower pressure ranges. Sensitivity, a critical parameter for effective FCPS performance, is investigated through a comprehensive series of simulation analyses employing finite element modeling. The study involves varying geometrical and mechanical parameters that influence FCPS performance, individually adjusting each parameter while keeping others constant. Microstructures such as cuboids, truncated pyramids with an aspect ratio of 0.5, cylinders, pyramids, and cones are modeled on the dielectric material surface. The parameters considered include inter-space, base length, height, and elastic modulus, to enhance FCPS sensitivity and linearity. Among the different shapes modeled, the cone exhibits the highest sensitivity, followed by the pyramid structure. Comparative analysis indicates that the cone and pyramid shapes demonstrate 15- and 10-times higher sensitivity, respectively, compared to the cuboid structure under an applied pressure of 10 Pa. Simulation results suggest that sensitivity can be finely tuned, with higher inter-space and microstructure height, as well as lower base length and Young's modulus of the dielectric material, contributing to increased sensitivity. However, it is noted that these conditions may lead to decreased capacitance in the absence of applied pressure due to air occupation relative to the dielectric material. The findings are further compared with existing literature, and the FCPS response analysis provides valuable insights for the future design of FCPS, particularly in the context of biomedical applications requiring precise low-pressure signal measurements. This research contributes to advancing the understanding of FCPS performance optimization and lays the groundwork for the development of sensors with enhanced sensitivity for bio-medical applications.

A Dual-FSM GI LiDAR Imaging Control Method Based on Two-Dimensional Flexible Turntable Composite Axis Tracking

In this study, a tracking and pointing control system with a dual-FSM (fast steering mirror) two-dimensional flexible turntable composite axis is proposed. It is applied to the target-tracking accuracy control in a GI LiDAR (ghost imaging LiDAR) system. Ghost imaging is a multi-measurement imaging method; the dual-FSM GI LiDAR tracking and pointing imaging control system proposed in this study mainly solves the problems of the high-resolution remote sensing imaging of high-speed moving targets and various nonlinear disturbances when this technology is transformed into practical applications. Addressing the detrimental effects of nonlinear disturbances originating from internal flexible mechanisms and assorted external environmental factors on motion control’s velocity, stability, and tracking accuracy, a nonlinear active disturbance rejection control (NLADRC) method based on artificial neural networks is advanced. Additionally, to overcome the limitations imposed by receiving aperture constraints in GI LiDAR systems, a novel optical path design for the dual-FSM GI LiDAR tracking and imaging system is put forth. The implementation of the described methodologies culminated in the development of a dual-FSM GI LiDAR tracking and imaging system, which, upon thorough experimental validation, demonstrated significant improvements. Notably, it achieved an improvement in the coarse tracking accuracy from 193.29 μrad (3σ) to 87.21 μrad (3σ) and enhanced the tracking accuracy from 10.1 μrad (σ) to 1.5 μrad (σ) under specified operational parameters. Furthermore, the method notably diminished the overshoot during the target capture process from 28.85% to 12.8%, concurrently facilitating clear recognition of the target contour. This research contributes significantly to the advancement of GI LiDAR technology for practical application, showcasing the potential of the proposed control and design strategies in enhancing system performance in the face of complex disturbances.

Temperature-dependent thermal buckling and free vibration behavior of smart sandwich nanoplates with auxetic core and magneto-electro-elastic face layers

AbstractThis article addresses the thermomechanical thermal buckling and free vibration response of a novel smart sandwich nanoplate based on a sinusoidal higher-order shear deformation theory (SHSDT) with a stretching effect. In the proposed sandwich nanoplate, an auxetic core layer with a negative Poisson’s ratio made of Ti-6Al-4V is sandwiched between Ti-6Al-4V rim layers and magneto-electro-elastic (MEE) face layers. The MEE face layers are homogenous volumetric mixtures of cobalt ferrite (CoFe2O4) and barium titanate (BaTiO3). The mechanical and thermal material properties of the auxetic core and MEE face layers are temperature-dependent. Using Hamilton’s principle, governing equations are constructed. To characterize the size-dependent behavior of the nanoplate, governing equations are adapted with the nonlocal strain gradient theory (NSGT). By applying the principles of Navier’s technique, closed-form solutions are obtained. Parametric simulations are carried out to examine the effects of auxetic core parameters, temperature-dependent material properties, nonlocal parameters, electric, magnetic, and thermal loads on the free vibration and thermal buckling behavior of the nanoplate. According to the simulation results, it is determined that the auxetic core parameters, temperature-dependent material properties, and nonlocal factors significantly affect the thermomechanical behavior of the nanoplate. The outcomes of this investigation are expected to contribute to the advancement of smart nano-electromechanical systems, transducers, and nanosensors characterized by lightweight, exceptional structural integrity and temperature sensitivity. Also, the auxetic core with a negative Poisson’s ratio provides a metamaterial feature, and thanks to this feature, the proposed model has the potential to be used as an invisibility technology in sonar and radar-hiding applications.

Customer-centric virtual reality applications adoption in the hospitality industry: quality-value-based adoption model

PurposeThe massive adoption of virtual reality (VR) applications has started since the COVID-19 pandemic, and until now, VR applications are still being used. However, there is limited research that analyses the consumer's perspective on the adoption of VR applications. Thus, this study discovers the adoption of VR applications in the hospitality sector by integrating the value-based adoption model (VAM) and VR quality.Design/methodology/approachThe data were gathered through a survey of 500 respondents and evaluated through the structural equation model-partial least squares (SEM-PLS).FindingsEmploying SEM-PLS and importance-performance map analysis (IPMA), the findings revealed that VR quality and perceived value are essential determinants in the adoption of VR applications in the hospitality industry.Practical implicationsPractically, this study encourages the hospitality industry to create and develop high-quality VR application technology to benefit visitors. Through this study, hospitality marketing managers, governments and others concerned with the hospitality industry’s future development can create effective ways to increase the adoption of VR applications in this industry.Originality/valueThis study offers novel perspectives into the theory and application of VR quality and VAM in the adoption of VR applications in the hospitality industry.

Ethylene Glycol Co‐Solvent Enables Stable Aqueous Ammonium‐Ion Batteries with Diluted Electrolyte

AbstractAqueous ammonium‐ion batteries (AAIBs) are considered as one of the most promising technologies for large scale energy storage applications, due to their intrinsic safety, environmental friendliness and low cost. Nevertheless, the practical application of AAIBs is impeded by hydrogen evolution reaction (HER) occurring in diluted aqueous electrolyte. Highly concentrated electrolytes can improve electrochemical stability but lead to higher costs and increased hydrolysis of NH4+. In this work ethylene glycol (EG) is proposed as co‐solvent, which can act as H‐bond modulating agent, to increase the stability of AAIBs with diluted electrolytes. The perturbation of water H‐bond network regulated by EG is proved by spectroscopic methods, while the suppressed HER is confirmed by differential electrochemical mass spectrometry (DEMS) results. As a result, full cells with 3,4,9,10‐perylenebis(dicarboximide) (PTCDI) anode and FeFe(CN)6 (FeHCF) cathode and EG‐added electrolyte exhibit stable cycling performance with capacity retention of 77% after 1950 cycles.

DEVELOPMENT OF THE DERMAL EFFECT OF PESTICIDES ON PROFESSIONAL CONTINGENTS USING INNOVATIVE 3RIVE 3D TECHNOLOGY

The skin is the most vulnerable organ when spraying pesticides on fields. Farmers are also exposed to pesticides during mixing, loading of pesticides, and when cleaning equipment and disposing of empty containers. The aim. To study and analyze the features of the risk of pesticides dermal exposure to professional contingents during treatments using the innovative 3RIVE 3D pesticide application technology. Materials and methods. The 3RIVE 3D innovative technological system of introducing was used to applicate Brigade 3Rive 3D, SC formulation. Field experiments on the study of working conditions when using the pesticide were conducted in various soil and climatic regions of Eastern Europe. Statistical processing of the results was carried out using a package of licensed statistical programs IBM SPSS StatisticsBase v.22 and MS Excel. Research results and discussion. During the conducted research, no bifenthrin contamination was found on the open skin of the operator and the tractor driver, who were processing corn crops with the Brigade 3Rive 3D, SC formulation. However, the operator's gloves were found to contain 0.025 mg of bifenthrin. Calculation of the unitless CASd value on the possibility of skin acute effects when applying the formulation showed that bifenthrin and the Brigade 3Rive 3D, SC formulation based on it are characterized by sufficient selectivity of action on the target object (CASd – 645 and 162, respectively, i.e. > 100) and a low level of danger acute dermal toxic effects for workers, which is due to low values of effective consumption rates. The real dermal risk of bifenthrin exposure when using the Brigade 3Rive3D, SC formulation was significantly lower compared to the risk of workers involved in “traditional” air treatment and treatment with unmanned aerial vehicles (UAVs) (p=0.009-0.048 according to Wilcoxon's W-criterion); in comparison with rod and fan processing – it is non-significantly lower (р=0.262-1.000). There was a similar picture in comparison with the dermal aggravated risk – significantly lower in comparison with the risk of workers involved in “traditional” air treatment and processing with the help of UAVs (p=0.009 according to Wilcoxon's W-criterion); in comparison with rod and fan treatment – non-significantly lower (р=0.262-1.000). Conclusion. It was established that the studied active substance bifenthrin and the Brigade 3Rive 3D, SC formulation based on it are characterized by sufficient selectivity of dermal action on the target object and a low probability of acute dermal effects. A higher probability of acute inhalation poisoning than dermal exposure was revealed.

Enabling Low Pressure, Low Temperature, and Particle Control for Anisotropic Conductive Adhesives

AbstractAnisotropic conductive adhesives (ACAs) are the preferred interconnection technology for applications that employ large dies, flexible substrates, and ultra fine‐pitch interconnects. Conventional ACAs require relatively high bonding pressures and temperatures, and ultra fine‐pitch applications challenge the trade‐off between low interconnect resistance and risk of short circuits. This study introduces an ACA‐like interconnection technology that addresses these limitations, allowing for low‐pressure, low‐temperature assembly processes with enhanced particle control at the interconnects. Conductive particles are deposited onto a patterned carrier and subsequently transferred to electrical pads using either non‐conductive film or Ag sintering. The Ag sintering process is performed at a low temperature (140 °C) and low bonding pressure (1 N for a 10 × 10 mm2 chip). The capability of controlling the position and number of conductive particles within individual interconnects is demonstrated. This presents possibilities for achieving ultra‐fine pitch interconnects with negligible risk of short circuits, without compromising electrical resistance. It is demonstrated that interconnect resistance can be tuned by varying the number of conductive particles (achieving a resistance as low as 33 mΩ with 25 particles per interconnect). This approach is applicable to scenarios where the bonding force and temperature must remain low due to the nature of substrate materials.

Exploring Nanomaterials for Hydrogen Storage: Advances, Challenges, and Perspectives.

Hydrogen energy heralded for its environmentally friendly, renewable, efficient, and cost-effective attributes, stands poised as the primary alternative to fossil fuels in the future. Despite its great potential, the low volumetric density presents a formidable challenge in hydrogen storage. Addressing this challenge necessitates exploring effective storage techniques for a sustainable hydrogen economy. Solid-state hydrogen storage in nanomaterials (physically or chemically) holds promise for achieving large-scale hydrogen storage applications. Such approaches offer benefits, including safety, compactness, lightness, reversibility, and efficient generation of pure hydrogen fuel under mild conditions. This article presents solid-state nanomaterials, specifically nanoporous carbons (activated carbon, carbon fibers), metal-organic frameworks, covalently connected frameworks, nanoporous organic polymers, and nanoscale metal hydrides. Furthermore, new developments in hydrogen fuel cell technology for stationary and mobile applications have been demonstrated. The review outlines significant advancements thus far, identifies key barriers to practical implementation, and presents a perspective for future sustainable energy research. It concludes with recommendations to enhance hydrogen storage performance for cost-effective and long-lasting utilization.

Effect of the component and the concentration ratio on the removal of volatile organic compound mixtures by non-thermal plasma

Abstract The feasibility and efficiency of the degradation of volatile organic compounds (VOCs) by non-thermal plasmas(NTP) has been extensive investigated and proved in laboratory experiments with single target component. In practical, multicomponent VOCs are emitted during industrial production. It is urgent need to study the abatement of multicomponent VOCs to evaluate the effectiveness of NTP technology in application, and explore the impact of interactions between VOCs components on degradation efficiency. This study focused on the degradation of VOCs mixtures composed of toluene (TOL), acetone (AC), and ethyl acetate (EA) by dielectric barrier discharge (DBD) plasma in room temperature. Through changing the target gas in turn and the concentration ratio of additive gas in binary mixture, the influence of the composition and the concentration ratio of the additive gases on the target gas degradation have been investigated by comparing the decomposition of the single compound. The results showed that AC and EA had little or no inhibitory effect on degradation of TOL. When AC was added and degraded together with TOL, the degradation rate of TOL remained almost unchanged with slight fluctuations in the range of 75.3 ± 1.0% as the ratio of added AC increased. However, TOL significantly inhibited the degradation of EA, and AC, and more seriously on AC. When the ratio of added TOL increased, the degradation rates of EA or AC changed from 41.1% or 34.5% to 29.8% or 12.2%, which were 11.3% or 22.3% reduced respectively. It’s indicated that there was a mutual inhibitory effect between the AC and EA when they were degraded together, and a stronger inhibitory effect of EA on AC was observed. When the ratio of added AC to EA changed from 0:1 to 3:1, the degradation rate of EA decreased by 9.5%, from 49.8% to 40.3%. When the ratio of added EA to AC changed from 0:1 to 3:1, the degradation rate of AC decreased by 16.0%, from 37.9% to 21.9%.

Low-temperature direct diffusion bonding of Zr702 alloys via electric current assistance

Integrated zirconium (Zr) alloy fuel claddings require low-temperature and high-efficiency joining technologies for nuclear applications. However, conventional direct-joining technologies make it challenging to satisfy critical requirements at relatively low temperatures in a short time. As a promising alternative, the electric-current-assisted joining (ECAJ) method was studied to reduce the joining temperature and time required for the direct joining process. ECAJ was performed on a spark plasma sintering apparatus, with the specimens assembled with and without graphite dies in the two models. The microstructural evolution and mechanical properties of Zr/Zr joints were investigated at 600 − 900 °C for 1 s to 30 min under a pressure of 30 MPa using different configurations with or without a graphite die. While the joint quality varied with the joining conditions, no significant phase transformation, abnormal grain growth, or preferential orientation was observed at the interface. The maximum shear strength of 404 ± 78 MPa and hardness of 370.9 ± 49.8 HV were achieved at 600 °C for 10 min using a die-less configuration. The joining mechanism was discussed in terms of the potential thermal and electric effects inside the specimen, with the low-temperature joining mechanism attributed to the combined effect of transient overheating and electric-field-accelerated element self-diffusion at the interface, with the latter playing a leading role.

An innovative molecular approach towards the cost-effective entomological authentication of honey

Honey authentication and traceability are crucial not only for economic purposes but also for ensuring safety. However, the widespread adoption of cutting-edge technologies in practical applications has been hampered by complex, time-consuming sample pre-treatment processes, the need for skilled personnel, and substantial associated expenses. This study aimed to develop a simple and cost-effective molecular technique to verify the entomological source of honey. By utilizing newly designed primers, we successfully amplified the mitochondrial 16S ribosomal RNA gene of honey bees from honey, confirming the high quality of the extracted DNA. Employing RFLP analysis with AseI endonuclease, species-specific restriction patterns were generated for honey derived from six closely related honey bees of the Apis genus. Remarkably, this method was proven equally effective in identifying heat-treated and aged honey by presenting the same RFLP profiles as raw honey. As far as we know, this is the initial research of the simultaneous differentiation of honey from closely related honey bee species using the restriction endonuclease AseI and mitochondrial 16S rRNA gene fragments. As a result, it holds tremendous potential as a standardized guideline for regulatory agencies to ascertain the insect origins of honey and achieve comprehensive traceability.

Wetting and interfacial behavior of aqueous Deep eutectic solvents on Graphite, silica and calcite surfaces: Molecular dynamics study

Understanding the wetting behavior of liquids/fluids on solid surfaces at the nanoscale can help develop more effective and efficient technologies in various applications, including microfluidics, biomedical, enhanced oil recovery, and many others. Deep eutectic solvents (DESs) have recently gained attention due to their physical and chemical properties and tunability, making them useful in many applications. This article reports the investigation of the wetting behavior of aqueous deep eutectic solvent (DES) on graphite, silicon dioxide (SiO2), and calcite (CaCO3) using molecular dynamics (MD) simulation. The study's main objective is to understand the interfacial behavior of aqueous DES on these surfaces. In the current study, two different DESs, choline-chloride (ChCl) as hydrogen bond acceptor (HBA) and two different hydrogen bond donors (HBD), urea (U) and ethylene glycol (EG) with molar ratio 1:2are used. Aqueous DES has been studied for three different concentrations of10, 20, and 30 wt% of DES molecules to explore the effect of concentration.AqueousDES system on the graphite makes a finite contact angle for all concentrations of DES.In contrast, for SiO2 and CaCO3, droplets spread and attain a contact angle below ∼ 10° due to high hydrophilicity. We confirmed that our simulation had attained equilibrium by computing the interaction energy with the substrate and system molecules. The wetting behavior of aqueous DES thin film on the surfaceis characterizedby a density profile along the z-axis (normal to the surface). Furthermore, hydrogen bond (HB) analysisis performedto elucidate the structural relationship of these aqueous-DES systems. Overall, this study provides insights into the wetting behavior of nanodroplets/film of aqueous DES on different surfaces and illustrates the structural characteristics of these systems through various properties such as contact angle, density profiles, and hydrogen bonds.

Robust and durable superlubricity enabled by carboxylated graphene quantum dots in lubricated steel contacts

Achieving macroscale superlubricity on engineering steel by utilizing aqueous green lubricants has gained growing interest, given its substantial potential to reduce energy consumption and carbon footprint. However, maintaining superlubricity under diverse sliding conditions over a prolonged duration is a major obstacle for real-scale applications. Herein, we report that a robust and durable tribofilm enabled by a unique lubrication mechanism based on carboxylated graphene quantum dots (CGQDs) in aqueous glycerol triggers macroscale superlubricity in self-mated steel contacts. A dedicated intermittent test was designed to show the superlubricity's robustness and the ability of the tribofilm to adapt to a variety of relevant sliding conditions. Moreover, the boundary film provides an average coefficient of friction of around 0.007 and up to 69 % wear reduction (compared to the base lubricant), resulting in the maintenance of superlubricity at a real final contact pressure of 123 MPa, which increases the upper limit of the contact pressure compared to current aqueous-lubricated steel contacts. The new superlubricity mechanism was enabled by the chemical adsorption of the CGQDs onto the worn metal surface, coupled with the tribo-induced structural degradation and transformation of the CGQDs into layered graphitic structures that generate an adaptable low-shear interface. This work provides new insights into the role of chemical adsorption and structural transformation of CGQDs in achieving superlubricity and is an important step forward for implementing energy-efficient and green lubrication technologies for industrial applications.

Optimising fundamental knitting parameters for wearable triboelectric nanogenerators

During the past decade, Triboelectric Nanogenerators (TENG) have demonstrated their potential as an energy harvesting and self-powered sensing technology for future wearable applications. Among various TENG architectures, knitted textile TENGs have become increasingly popular in recent times, as they provide advantages such as high electrical outputs, very good mechanical properties and excellent wearability. However, there is still a lack of understanding on how to engineer the knitting parameters to maximize the electrical output generation of knitted textile TENGs. Herein, for the first time, we bridge this gap by mapping the relationship between basic knit parameters and the fundamental TENG parameters which govern their electrical outputs. In this work, the loop length, yarn count, number of yarns per loop and the loop structure of a knitted textile TENG are empirically varied and its impact on the charge, current and voltage outputs is studied. The observed output trends are then analysed in-depth using the distance-dependent electric field theory, thus, explaining the root causes of the observed output trends. Consequently, several new strategies on the design and optimisation of more efficient knitted textile TENGs are uncovered. Further, the impact of these optimisation strategies on the wearable properties of the knitted textile TENGs is studied, paving the way for practically applicable textile TENG designs with balanced electrical output generation and long-term wearability.

Microfluidic paper analytic device (μPAD) technology for food safety applications.

Foodborne pathogens, food adulterants, allergens, and toxic chemicals in food can cause major health hazards to humans and animals. Stringent quality control measures at all stages of food processing are required to ensure food safety. There is, therefore, a global need for affordable, reliable, and rapid tests that can be conducted at different process steps and processing sites, spanning the range from the sourcing of food to the end-product acquired by the consumer. Current laboratory-based food quality control tests are well established, but many are not suitable for rapid on-site investigations and are costly. Microfluidic paper analytical devices (μPADs) are a fast-growing field in medical diagnostics that can fill these gaps. In this review, we describe the latest developments in the applications of microfluidic paper analytic device (μPAD) technology in the food safety sector. State-of-the-art μPAD designs and fabrication methods, microfluidic assay principles, and various types of μPAD devices with food-specific applications are discussed. We have identified the prominent research and development trends and future directions for maximizing the value of microfluidic technology in the food sector and have highlighted key areas for improvement. We conclude that the μPAD technology is promising in food safety applications by using novel materials and improved methods to enhance the sensitivity and specificity of the assays, with low cost.