Metal Patterns Research Articles

Well-defined in-textile photolithography towards permeable textile electronics

Textile-based wearable electronics have attracted intensive research interest due to their excellent flexibility and breathability inherent in the unique three-dimensional porous structures. However, one of the challenges lies in achieving highly conductive patterns with high precision and robustness without sacrificing the wearing comfort. Herein, we developed a universal and robust in-textile photolithography strategy for precise and uniform metal patterning on porous textile architectures. The as-fabricated metal patterns realized a high precision of sub-100 µm with desirable mechanical stability, washability, and permeability. Moreover, such controllable coating permeated inside the textile scaffold contributes to the significant performance enhancement of miniaturized devices and electronics integration through both sides of the textiles. As a proof-of-concept, a fully integrated in-textiles system for multiplexed sweat sensing was demonstrated. The proposed method opens up new possibilities for constructing multifunctional textile-based flexible electronics with reliable performance and wearing comfort.

Charge‐Programmable Photopolymers for 3D Electronics via Additive Manufacturing

AbstractCharge‐programmed 3D printing enables the fabrication of 3D electronics with lightweight and high precision via selective patterning of metals. This selective metal deposition is catalyzed by Pd nanoparticles that are specifically immobilized onto the charged surface and promises to fabricate a myriad of complex electronic devices with self‐sensing, actuation, and structural elements assembled in a designed 3D layout. However, the achievable property space and the material‐performance correlation of the charge‐programmed printing remain unexplored. Herein, a series of photo‐curable resins are designed for unveiling how the charge and crosslink densities synergistically impact the nanocatalyst‐guided selective deposition in catalytic efficiency and properties of the 3D printed charge‐programmed architectures, leading to high‐quality 3D patterning of solid and liquid metals. The findings offer a wide tunability of the structural properties of the printed electronics, ranging from stiff to extreme flexibility. Capitalizing on these results, the printing and successful application of an ultralight‐weight and deployable 3D multi‐layer antenna system operating at an ultrahigh‐frequency of 19 GHz are demonstrated.

Quantification of toxic metals in chicken egg and chicken feed via SOM-artificial neural network.

Poultry products such as meat and eggs are rich sources of proteins, vitamins, and minerals. It is a good indicator of healthy food. Keeping in view, the present study is designed to evaluate the prevalence of toxic heavy metals (lead, nickel, cadmium, and chromium) in chicken eggs and feed. For this purpose, five samples of egg and feed were collected from five different commercial markets in Skardu City. Each sample was prepared using the wet digestion method and analyzed using a flame atomic absorption spectrophotometer. The results showed that lead, nickel, and chromium were present in varying amounts in the feed and egg, with nickel being the most concentrated metal, followed by lead and chromium in egg samples, while the feed samples showed the highest concentration of chromium followed by lead and nickel. However, concentrations of selected heavy metals except cadmium were all above the permissible limit of the World Health Organization. The self-organizing map-artificial neural network is employed for the identification of patterns of heavy metals in chicken feed and egg samples. The lower left neurons of the maps showed higher heavy metal concentrations found in samples taken from Bazar, whereas the rest of the samples showed varied concentrations. A comparison of feed and egg concentrations showed that nickel concentration was lower in feed samples than in egg samples. The lead concentration decreased in eggs except in the Krasmathang feed sample. Chromium concentration presented a negative correlation due to the extremely high concentration found in the Bazar feed sample.

Wide-Angle Beam Steering Closed-Form Pillbox Antenna Fed by Substrate-Integrated Waveguide Horn for On-the-Move Satellite Communications

Wide-angle mechanical beam steering for on-the-move satellite communications is presented in this paper based on a closed-form pillbox antenna system. It includes three main parts: a fixed-feed part, which is a substrate-integrated waveguide (SIW) horn with an extended aperture attached to a parabolic reflector; a novel quasi-optical system, which is a single coupling slot alongside and without spacing from the parabolic reflector; and a radiating disc, which is a leaky-wave metallic pattern. To make the antenna compact, pillbox-based feeding is implemented underneath the metallic patterns. The antenna is designed based on a substrate-guided grounded concept using leaky-wave metallic patterns operating at 20 GHz. Beam scanning is achieved using mechanical rotation of the leaky-wave metallic patterns. The proposed antenna has an overall size of 340 × 335 × 2 mm3, a gain of 23.2 dBi, wide beam scanning range of 120°, from −60° to +60° in the azimuthal plane, and a low side lobe level of −17.8 dB at a maximum scan angle of 60°. The proposed antenna terminal is suitable for next-generation ubiquitous connectivity for households and small businesses in remote areas, ships, unmanned aerial vehicles, and disaster management.

Fabrication of Porous Non‐Enzymatic Glucose Sensing Electrodes Through Nanosecond‐Laser Patterning of Metal–Organic Frameworks

AbstractNanosecond laser patterning of Copper Metal–Organic Framework (Cu‐MOF) coated substrates is performed to fabricate non‐enzymatic glucose sensing electrodes. The Cu‐MOF coated glass substrate with a cover glass is subjected to a laser patterning process; the amount of MOF, laser fluence, and scan speeds mainly influenced the patterning process. The electrodes are fabricated on coated and covered glass with varying electrical conductivity due to the high laser energy absorptivity. The patterned electrodes consist of graphitic carbon incorporated with nano‐Cu and show a stable electrical conductivity on the coated substrates. The electrodes are chemically active in the Fe2+/Fe3+ redox system; however, their activity varies with patterning conditions. The electrochemical studies in alkaline electrolytes reveal that the as‐fabricated electrodes can sense the glucose molecule in the linear concentration range of 0.025–1.0 and 1.0–10.0 mm, with a maximum sensitivity of 3260.3 µA mM−1 cm−2 and a response time of no more than 5 s, and a limit of detection (LOD) of 0.25 µm. The current recovery rate is higher (> 80%) when adding glucose molecules than when adding other interference molecules, confirming that the electrode is selective toward glucose sensing. The results reveal that the fabricated electrodes act as stable, reusable, non‐enzymatic glucose‐sensing electrodes.

A polarization conversion metasurface for reducing radar cross section and enhancing radiation performance of circularly polarized array antennas

In this paper, we present a metasurface for ultra-wideband polarization conversion. The unit structure of the PCM consists of a metallic pattern layer, an air layer, and a grounded dielectric layer, which can achieve a polarization conversion bandwidth (PCR) from 6.17 GHz to 19.5 GHz (103.9%). According to the phase cancellation principle, the PCM cells and their mirror cells are arranged in a checkerboard fashion to form a metasurface. Applying it to a circularly polarized patch array antenna for RCS reduction. With the addition of PCM, the impedance matching (S11) bandwidth of the antenna is broadened from 7.2 to 8.3 GHz (14.2%) to 6.2–8.4 GHz (30.1%), the axial ratio (AR) bandwidth is broadened from 6.9 to 8.25 GHz (17.8%) to 6.75–8.32 GHz (20.1%), the peak gain to 11.1 dBi and the antenna's monostatic RCS achieves more than 5 dB reduction from 6.4 to 18.6 GHz (97.6%) under x- and y-polarized plane wave irradiation.The current distribution of the antenna is used to explain the gain improvement. Finally, we fabricated and tested a prototype of the proposed metasurface antenna.

Total oxidation of toluene at low temperatures in air using sono-impregnated Mn/Cu bimetal over activated clinoptilolite as a nanocatalyst: Designing the oxidation reaction rate with the optimization of the fixed bed reactor CFD model

A series of manganese-copper oxides on clinoptilolite with various impregnation sequences were synthesized using ultrasonic irradiation. Their properties were characterized by XRD, BET, FTIR, FESEM, and EDX techniques. The XRD patterns confirmed the formation of Mn2O3/MnO and CuO as the crystalline phase on clinoptilolite. FESEM images confirmed that manganese and copper dispersed on support in nano-range size. EDX results indicated uniform dispersion of the elements. FTIR patterns demonstrated that surface groups of nanocatalysts agree with the patterns of metals and support applied in nanocatalysts synthesis. Catalysts were investigated in the oxidation of toluene from the polluted air. Results showed that bimetallic nanocatalysts are more active than single metal oxide nanocatalysts) Mn2O3/MnO/CuO(causing the synergism effect of active phases. The highest catalytic activity was observed on the Mn/Cu/CLT nanocatalyst in which excess manganese oxide as active sites existed on the support and led to a decreased complete oxidation temperature of toluene. The result of toluene oxidation from the polluted air demonstrated that the prepared nanocatalyst was very active and stable. Also, the Mars–Van Krevelen kinetic model and the calculated kinetic parameters of this model were used to develop and express the toluene catalytic oxidation reaction rate on newly synthesized catalysts using the combination of CFD method with an intelligent genetic optimization algorithm. All results obtained using this method have an RMSE less than 0.1. Also, the activation energy based on the Arrhenius law for the toluene oxidation reaction using the Mn/Cu/CLT optimal nanocatalyst was calculated by this method equal to 98480 J/mol with RMSE 0.0248.

Optical enhancement of perovskite solar cells by metallic nano-patterns

The integration of metallic nanoparticles (MNPs) with plasmonic effects is an alternate approach for managing photons and charge carriers, and is considered a promising method for advancing solar cell technologies. Plasmonic-enhanced solar energy harvesting involves three mechanisms: hot-electron injection, light trapping, and modulation of energy flow direction through dipole-dipole coupling. These phenomena have been observed to significantly enhance the performance of silicon, gallium arsenide, dye-sensitized, and organic solar cells. However, for emerging perovskite solar cells, the light trapping effect, specifically, the far-field scattering via MNPs, has been seldom reported. The anomalous phenomenon is primarily attributed to the size constraints imposed on MNPs by the thickness of the functional layers in cell devices. According to the theory of localized surface plasmon resonance (SPR), the characteristic size of the MNPs needs to be larger than 90 nm to achieve optimal photon scattering. Conversely, charge transport layers like NiO<sub>x</sub> and SnO<sub>2</sub> in perovskite solar cells are typically thin, ranging from a few to several tens of nanometers in thickness. Therefore, the community of perovskite solar cells still faces a great challenge in harvesting light through plasmonic scattering.<br>Compared to MNPs, the shape, size, periodicity, and other characteristic parameters of two-dimensional metal patterns within the horizontal plane are not limited by the thickness of the device's functional layer, thus enabling a more flexible regulation of the SPR response band, vibration intensity, and dissipation method of plasmonic energy. In this study, based on the finite-difference time-domain (FDTD) method and rigorous coupled-wave analysis (RCWA), we systematically investigated the SPR spectra of different metal patterns. The results demonstrate that by optimizing characteristic parameters such as pattern shape, thickness, and periodicity, a significant SPR phenomenon can be observed in the near-infrared region, with scattering dominating over extinction. For the optimal metal ring pattern, the SPR peak corresponds to a wavelength of 772 nm, with relative absorption, scattering, and extinction cross-sections of 0.54, 1.39, and 1.93, respectively. The weighted average absorption of the perovskite response layer in the range of 700-850 nm increased from 53.61% to 65.36%. Correspondingly, the photocurrent density of the device increased from 20.39 to 22.72 mA/cm<sup>2</sup>, and the photoelectric conversion efficiency was relatively improved by 11.45%. This research provides a novel path for light trapping design in perovskite solar cells in the near-infrared region, and serves as a "spectrum-based" reference for SPR regulation in other similar devices.

A Low RCS Waveguide Slot Antenna array with Metamaterial Absorber

We propose a novel design to reduce the radar cross section (RCS) of ridged waveguide slot antenna array with metamaterial absorber (MMA). The MMA consists of metallic pattern and solid metal on sides of a dielectric slab, of which the absorbing characteristics and mechanism are analyzed. The PEC ground plane of a ridged waveguide slot antenna array is covered by MMA. Both the simulated and measured results show that compared with the waveguide slot antenna array with a PEC ground plane, the RCS of proposed antenna array are reduced dramatically without degradation of antenna performance. Combining with the bandpass frequency selective surfaces technology, the guideline illustrated by the proposed examples will serve as a good candidate for the future design of low RCS antenna.

Design of broadband metamaterial absorber utilized by flower-shaped unit loaded with lumped-resistor

A metamaterial broadband absorber is designed by means of metal pattern and lumped resistance. The optimal structural parameters and resistance are scanned in certain steps to determine. The maximum absorbing bandwidth can achieve up to 8.2 GHz with 3 mm thickness. Subsequently, the angle stability of the absorber can be improved by adding vertical metal through holes. After optimization, the maximum absorbing bandwidth can be further increased to 9.1 GHz (8.3–17.4 GHz), and the effective absorption bandwidth of 3.7 GHz (9.53–13.25 GHz) can still be achieved when the incident angle is 60°. Further analysis reveals that the dissipation of the electromagnetic wave is achieved by ohmic loss caused by the resistive element and magnetic resonance caused by the induced circular current, rather than by temperature or other factors. Finally, to verify the real performance of the designed metamaterial absorber, a 30 cm × 30 cm sample was fabricated, and the reflection coefficient was tested by the NRL arch test method. The results showed that the measured return loss of the absorber was consistent with the simulation results.

Reactive Aerosol Jet Printing of 2D and 3D Ag Patterns

Printed electronics is a rapidly growing field that involves the use of printing technologies to create electronic devices such as sensors, displays, and solar cells 1. Unlike traditional electronics, which rely on rigid and bulky components, printed electronics can be obtained on flexible and lightweight substrates such as plastic and paper, allowing the development of novel applications such as wearable electronics, smart packaging, and medical sensors. Printing technologies uniquely feature miniaturization and patterning capability at low-cost and high-throughput production. Among them, screen-printing, inkjet printing (IJP) and aerosol jet printing (AJP) are the most employed to fabricate conductive metallic patterns of Ag, Au, Cu and other metal nanoparticles (NPs). These printing techniques typically requires concentrated ink of metal NPs. However, specially in the case of IJP and AJP the synthesis of very small NPs (d < 100 nm) as well as proper ink formulation and long-time stability are major limitations to printing conductive metallic patterns 2.In this work, we propose an innovative method to produce 2D and 3D patterns and structures of Ag NPs by reactive Aerosol Jet Printing (r-AJP) on different substrates, using a custom-built aerosol jet printer. Ag NPs were in-situ reduced coupling two aerosol streams carrying the Ag precursor and a reducing agent, respectively. The process is fast, scalable and cheap. The electrical properties, in terms of both linear and areal electrical conductivity, of the r-AJP silver structures metallization patterns were investigated. Furthermore, the effect of both process parameters and precursor solution physical properties on printed Ag structure and morphology was assessed by x-ray diffraction (XRD) and scanning electron microscopy (SEM) in order to define the optimized condition for high definition 2d and 3D patterns by r-AJP. Bibliography P. Martins et al., Advanced Functional Materials, 33, 2213744 (2023).Y. Sui and C. A. Zorman, J. Electrochem. Soc., 167, 037571 (2020).

(Invited) Fabriations and Applications Using Liquid Metal Towards Stretchable Electronics

Highly deformable devices have many potential applications, including wearable electronics, robotics and health monitoring. Mechanically deformable devices and sensors can conformally cover electronic systems on curved or soft surfaces. Liquids deform more easily than solids, so sensors and actuators that utilise liquids trapped in soft templates as sensing components are ideal platforms for such applications. Such highly deformable electronics using ultra-flexible conductive materials are called stretchable electronics. Liquid metals (LMs) are one of the leading materials. In the last few years, liquid metals have steadily gained interest, especially in the field of flexible soft electronics and related applications. The term liquid metal has several definitions and many research efforts are underway to utilise liquid metals in various fields. The simplest definition can be given as 'a composite of low-melting alloys that retain their liquid state at room temperature, are easily deformable and have high electrical conductivity'. Here, an overview of liquid metals, new processing methods, sensors and actuators, batteries and smart devices are reported in focus.To date, we have adopted a patterned method using microfluidic channels with regard to processing methods for liquid metals such as EGaIn and Galinstan. Microfluidic channels are one of the most accurate and reliable method of producing electrode patterns among the three processing methods, although they are limited by the substrate material and pattern design for pattern fabrication. The creation of microfluidic channels follows the method used in Micro Electro Mechanical Systems (MEMS) and micro Total Analysis Systems (microTAS). In practice, the molds are fabricated by photolithography using SU-8 photoresist. Rubber materials such as polydimethylsiloxane (PDMS) are poured into the mold and allowed to cure. Microfluidic channels are fabricated by chemically bonding the flat PDMS with the PDMS to which the pattern has been transferred. We have succeeded in fabricating a two-dimensional pattern of liquid metal by the method described above. Furthermore, we have successfully fabricated microfluidic channels by 3D printing of rubber materials and constructed 3D circuits by using liquid metal. As liquid metal is a liquid material, processing methods centred on "printing" processing can be used, and the most suitable processing method can be selected according to the device and application.Physical sensors such as strain sensors and chemical sensors such as oxygen gas sensors have been reported using liquid metal wiring. By optimising the wiring of the liquid metal, capacitor structures and resistors can be fabricated. By encapsulating these in a flexible material, PDMS, it is possible to realize sensors that can measure displacements such as strain. Indeed, by optimising three sensor structures, we have reported a physical sensor capable of sensing three sensing modes: two-dimensional tension and vertical compression. However, taking into account the actual application in wearable devices for healthcare applications such as pulse rate, a detection sensitivity below 1 k Pa is required. The authors realized a high-sensitivity pressure sensor by using a Wheatstone bridge circuit structure for the liquid metal wiring in the PDMS to form a Diaphragm sensor. In fact, a pulse rate sensing device was realized based on the developed device. Furthermore, a PDMS glove capable of measuring 16 points simultaneously was realized by attaching the developed pressure sensor to a hand mold using 3D printing5).Such physical sensors are very easy to construct and can be realized with one type of liquid metal. While there are many different types of liquid metals as described above, liquid metals easily mix when they come into contact with each other. Therefore, the authors proposed a "liquid" state heterojunction using ionic liquids and liquid metals with extremely low vapor pressure. By using ionic liquids [EMIM][Otf], [EMIM][PF6] and [EMPYR][NTf2], sensors for temperature, humidity and oxygen gas were realized. Furthermore, with regard to their sensitivity, the detection sensitivity was 10 times higher than that of normal metal temperature and humidity sensors for temperature and humidity sensors. In this study, heterojunctions were realized using microfluidics. Due to the low Reynolds number of the microfluidics, the robustness of the liquid state heterojunction with respect to deformation was also very high due to the high viscosity effect, making the configuration suitable for stretchable sensors. In addition to electrodes and sensors, development of batteries and smart devices has also been initiated and will be reported in this presentation.

(Invited) Electrodeposition of In and Ga from Non-Aqueous Electrolytes

Indium and gallium are metals whose applications have increased during the last decades. Both metals are primarily used in the form of binary, tertiary or quaternary (semi)conductor compounds in integrated circuits, photovoltaics, liquid crystal display devices, lasers and light-emitting diodes.In the past, the electrodeposition of indium and gallium has been investigated from both aqueous and non-aqueous electrolytes. Due to the negative standard reduction potentials of the two metals (E°In(III)/In(0) = −0.34 V and E°Ga(III)/Ga(0) = −0.53 V), their electrodeposition from aqueous electrolytes is hampered. This is especially true for gallium. In this talk, the electrodeposition of indium and gallium was investigated from several organic solvents. The investigated electrolytes are 1,2-dimethoxyethane (DME), polyethylene glycol (PEG), dimethyl sulfoxide (DMSO), and acetonitrile, containing chloride, bistriflimide, or methanesulfonate-based indium or gallium precursors.The electrochemistry and the electrodeposition of indium and gallium was studied using various electrochemical methods in combination with quartz crystal microbalance (QCM) and rotating (ring) disk electrodes. DMSO-based electrolytes enabled the electrodeposition of indium at room temperature and above its melting point (159.6 °C), while DME electrolytes gave rise to gallium electrodeposits composed of small liquid gallium spheres (Fig 1). In all the investigated electrolytes, the formation of intermediate monovalent indium(I) or gallium(I) species during reduction and oxidation was demonstrated. These species are unstable and react away via disproportionation reactions. Yet, it was found that the extent of their formation and their stability depends on the nature of the electrolyte. In addition, the electrodeposition of indium antimonide (InSb) films and eutectic gallium indium (EGaIn) liquid metal lines and patterns will be discussed, as well as the electrochemical synthesis of spherical indium nanoparticles.

(Invited) Plasma-Enhanced Atomic Layer Etching for Metals and Dielectric Materials

The critical dimensions of semiconductor devices are continuously shrinking with 3D device structure and are approaching to nanometer scale. The demand for dimension control in angstrom level is drastically increasing also in etching processes. Atomic layer etching (ALE) processes are being actively studied and developed for various semiconductor, dielectric materials as well as metals. In this talk, various plasma-enhanced ALE (PEALE) processes will be discussed for isotropic and anisotropic patterning of metals and dielectric materials such as molibdenum, ruthenium, cobalt, titanium nitride, tantalum nitride, halfnium oxide, zirconium oxides.[1-7] Typical ALE processes consist of surface modification step and removal step. For the surface modification, various fluorination, chlorination and oxidation schemes are applied through fluorocarbon deposition, halogenation, oxidation with radicals generated plasmas. For the removal or etching step, various schemes were applied including ion-bomardment, heating, ligand volatilization, ligand exchange, and halogenation. The surface characteristics and requirements of plasma-enhanced ALE will be also discussed.1) K. Koh, Y. Kim, C.-K. Kim, H. Chae, J. Vac. Sci. Technol. A, 36(1), 10B106 (2017)2) Y. Cho, Y. Kim, S. Kim, H. Chae, J. Vac. Sci. Technol. A, 38(2), 022604 (2020)3) Y. Kim, S. Lee, Y. Cho, S. Kim, H. Chae, J. Vac. Sci. Technol. A, 38(2), 022606 (2020)4) D. Shim, J. Kim, Y. Kim, H. Chae, J. Vac. Sci. Technol. B., 40(2) 022208 (2022)5) Y. Lee, Y. Kim, J. Son, H. Chae, J. Vac. Sci. Technol. A., 40(2) 022602 (2022)6) J. Kim, D. Shim, Y. Kim, H. Chae, J. Vac. Sci. Technol. A., 40(3) 032603 (2022)7) Y. Kim, S. Chae, H. Ha, H. Lee, S. Lee, H. Chae, Appl. Surf. Sci. 619, 156751 (2023)

Stretchable Electrodes for Medical Devices

[Key topics: ElectrodesElectrodeposition techniquesElectrochemical propertiesStructure – physical properties relationships] The fabrication of electrodes on polymers, and especially on elastomers, is relevant in several fields. Among them, the medical field can benefit a lot from these kinds of electrodes. The human body uses electrical signaling in the muscles as well as in the nervous system to transfer energy and information between the brain and the rest of the body. Cardiac pacemakers, neuromodulation systems, neuromonitoring systems, brain machine interfaces are all examples where electrodes play a key role. Most of the body tissues are soft with unique shapes. When it is required to transfer electrical signals between the soft tissues and hard electronic systems, having soft and conformable interfaces might be particularly advantageous to increase the efficacy of the therapies, the energy consumption of the medical devices and the patient’s quality of life.We have developed several solutions to obtain metal patterns on elastomers that are stretchable, strongly adhered and with high charge-storage capacity. The methods are based on SCBI (Supersonic Cluster Beam Implantation) that allows to form a nanocomposite made of metal nanoparticles embedded in the elastomer, which acts as seed where thin film electrodes are created either through physical vapor techniques or by electro or electroless deposition.Here we compare electrodes made of Pt, Pt-Ir, Ir and IrOx obtained via electrochemical and physical vapor techniques. We present how, by tuning the process parameters, is possible to control the electrodes properties such as the charge-storage capacity, the corrosion under electrical stimulation and stability to tensile and compressive stresses. We show how the electrochemical and mechanical properties are correlated to the micro-structure, the grain morphology, and the stoichiometry. It is also shown how obtaining the electrodes with the right specific surface area is essential to guarantee stability against corrosion under high currents input.

The Impact of Measurement Conditions on Solar Cell Efficiency

Precise solar cell measurements become more and more challenging due to the increasing complexity of metallization patterns and the sensitivity to rear side illumination for bifacial cell concepts. In this context, the measurement conditions under which conversion efficiencies are determined need to be closely examined: Different efficiency values can occur for the same solar cell because of different measurement conditions. To provide more transparency, a notation has recently been published, which unambiguously characterizes the measurement conditions used and which is included in the calibration documents of the calibration laboratories ISFH CalTeC and Fraunhofer ISE CalLab PV Cells. As this notation is held rather technical and no quantitative assessment is given so far, herein, the effects associated with different measurement conditions are analyzed and quantified in detail for typical industrial‐type solar cells. It is shown that varying the measurement conditions as well as the busbar concept can lead to significant differences in measured efficiency of 0.5%abs. The power gains coming from different cell measurement configurations do not occur in the same manner on the module level though and can lead to considerable variations in cell‐to‐module power factors. Several hints to increase the significance of solar cell measurements are given.

Occurrence and patterns of metals in mangrove forests from the Oman Sea, Iran

Concentrations of selected metals were investigated in roots, stems, leaves and sediments from mangrove forests situated along the coast of the Oman Sea, Iran. Results showed that the overall average concentrations of lead, nickel, copper, and zinc in sediments were 47.90, 54.12, 42.13 and 44 μg/g dry weight (dw) and 3.81, 16.41, 29.23 and 25 μg/g dw in plant tissues, respectively. In addition, the bioconcentration factors (BCFs) of root, stem and leaf ranged from 0.5 to 1.7, 0.2 to 1.5, and 0.4 to 1.3, respectively. Pollution indices showed that all investigated sites were in the category of low to moderate pollution (pollution load index: 1.5–0.11), with a 21 % probability of biological toxicity.

Assessment and computational bioevaluation of heavy metals from selected cosmetic products.

Heavy metal toxicity in environment has been an increasing issue for last decades, though now the attention has diverted to presence of heavy metals in cosmetic products. The aim of this study was to determine the concentration of selected heavy metals in cosmetic products (lipsticks and foundations) using ICP-OES. Health risk assessment was done by using hazard quotient (HQ) and hazard index (HI). HQ for lipsticks was below the safe limit (HQ = < 1) while for foundations it exceeded the safe limit (HQ = >1). Mostly, mercury (Hg) and iron (Fe) were found to be exceeding the permissible limit, the allowed limits are Hg, 1 ppm; Fe, 10 ppm; Cd, 0.3 ppm; and Cr, 1 ppm. Iron was found to be highest in lipsticks (123.86 ± 1.05 ppm) as well as in foundations (34.52 ± 0.08 ppm). Health risk assessment was done by using hazard quotient (HQ) and hazard index (HI). HQ for lipsticks was below the safe limit (HQ = < 1) while for foundations it exceeded the safe limit (HQ = >1). To understand the binding pattern of heavy metals to skin targets, molecular docking studies were carried out. This revealed the potentially harmful behavior of these heavy metals on the skin. This will provide new direction for the structural changes of consistence and activity of macromolecules in our body. Research proved that prolonged use of cosmetic products containing heavy metals can be harmful and sometimes fatal to human life as these heavy metals can penetrate through the skin and target the skin enzymes, disrupting their normal function leading to various skin related issues such as dermatitis (itching, redness, burning) hence the monitoring of cosmetic products is necessary for safety of human being.

Heavy Metal Pollution Assessment in the Agricultural Soils of Bonao, Dominican Republic

Heavy metal content in agricultural soils potentially impacts the food chain and human health. The present study assessed the levels of heavy metals in topsoil samples collected within an agricultural region situated in Bonao, Dominican Republic. The Energy-Dispersive X-ray Fluorescence (EDXRF) technique was utilized to measure the concentrations of iron (Fe), manganese (Mn), chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), lead (Pb), and arsenic (As) in the samples. The assessment of soil pollution status and potential ecological risk (RI) involved the utilization of various soil pollution indices, such as the single pollution index (PI), integrated pollution index (IPI), and enrichment factor (EF). The average total concentrations of Fe, Mn, Cr, Cu, Ni, Zn, Pb, and As were 103,000, 2000, 347, 36, 92, 32, 9.6, and 4.2 mg·kg−1, respectively. The results showed that the Mn, Ni, Cu, and As levels exceeded the Food and Agriculture Organization (FAO)’s recommended levels for healthy agricultural soils. The distribution pattern of each individual metal was different, indicating they had different sources of origin. The average pollution indices indicated low-to-moderate pollution, and the potential ecological risk obtained was low. This study emphasizes the need for soil management practices to mitigate heavy metal contamination for food safety and environmental health.

Cu Distribution Pattern Controlled Active Species Generation and Sulfamethoxazole Degradation Routes in a Peroxymonosulfate System

The distribution pattern of metals as active centers on a substrate can influence the peroxymonosulfate (PMS) activation and contaminants degradation. Herein, atomic layer deposition is applied to prepare Cu single atom (SA-Cu), cluster (C-Cu), and film (F-Cu) decorated MXene catalysts by regulating the number of deposition cycles. In comparison with SA-Cu-MXene (adsorption energy (Eads) = −4.236 eV) and F-Cu-MXene (Eads = −3.548 eV), PMS is shown to adsorb preferably on the C-Cu-MXene surface for activation (Eads = −5.435 eV), realizing higher utilization efficiency. More SO4− are generated in C-Cu-MXene/PMS system with steady-state concentration and 1–3 orders of magnitude higher than those in the SA-Cu-MXene and F-Cu-MXene activated PMS systems. Particularly, the contribution of SO4− oxidation to sulfamethoxazole (SMX) degradation followed the order, C-Cu-MXene (97.3%) > SA-Cu-MXene (90.4%) > F-Cu-MXene (71.9%), realizing the larger SMX degradation rate in the C-Cu-MXene/PMS system with the degradation rate constants (k) at 0.0485 min−1. Additionally, SMX degradation routes in C-Cu-MXene/PMS system are found with fewer toxic intermediates. Through this work, we highlighted the importance of guided design of heterogeneous catalysts in the PMS system. Appropriate metal distribution patterns need to be selected according to the actual water treatment demand. Metal sites could be then fully utilized to produce specific active species to improve the utilization efficiency of the oxidants.