Atomic Force Microscopy Analysis Research Articles

Unlocking the power of Inula Viscosa essential oil: A green solution for corrosion inhibition in XC48 steel within acidic environments

A sustainable corrosion inhibitor for XC48 steel in a 1 M HCl environment was effectively formulated using the essential oil of Inula viscosa (IVEO), as corroborated by gas chromatography-mass spectrometry (GC-MS) results. This novel application was assessed via multiple techniques: mass loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), Fourier-transform infrared spectroscopy with an attenuated total reflectance accessory (FT-IR/ATR), X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) and Atomic Force Microscopy (AFM) for surface examination. The plant extract’s inhibitory capacity raised in proportion to its concentration, as confirmed by both mass loss and electrochemical investigations. This trend reached a high point at a 97% inhibitory efficiency at a concentration of 400 ppm at 298 K. FTIR, XRD, SEM/EDS, and AFM analyses further validated the binding of this eco-friendly inhibitor onto the steel surface, which exhibited mixed-type characteristics, thus elucidating its exceptional inhibitory performance. The Langmuir isotherm model aptly fitted the adsorption analysis, indicating the development of an organic protective layer. Advances computational calculations of various quantum chemical parameters for the key ingredients of the essential oil added to the understanding of the link between adsorption and corrosion inhibition.

A Multidisciplinary Evaluation of Three-Dimensional Polycaprolactone Bioactive Glass Scaffolds for Bone Tissue Engineering Purposes.

In the development of bone graft substitutes, a fundamental step is the use of scaffolds with adequate composition and architecture capable of providing support in regenerative processes both on the tissue scale, where adequate resistance to mechanical stress is required, as well as at the cellular level where compliant chemical-physical and mechanical properties can promote cellular activity. In this study, based on a previous optimization study of this group, the potential of a three-dimensional construct based on polycaprolactone (PCL) and a novel biocompatible Mg- and Sr-containing glass named BGMS10 was explored. Fourier-transform infrared spectroscopy and scanning electron microscopy showed the inclusion of BGMS10 in the scaffold structure. Mesenchymal stem cells cultured on both PCL and PCL-BGMS10 showed similar tendencies in terms of osteogenic differentiation; however, no significant differences were found between the two scaffold types. This circumstance can be explained via X-ray microtomography and atomic force microscopy analyses, which correlated the spatial distribution of the BGMS10 within the bulk with the elastic properties and topography at the cell scale. In conclusion, our study highlights the importance of multidisciplinary approaches to understand the relationship between design parameters, material properties, and cellular response in polymer composites, which is crucial for the development and design of scaffolds for bone regeneration.

Isotactic-polypropylene (iPP) wettability modified by surface DBD plasma

Abstract In this paper, atmospheric pressure plasma of ambient air was generated by surface dielectric barrier discharge (SDBD) device for the purpose of modifying the surface of isotactic-polypropylene (iPP). The effect of SDBD treatment time on the chemical and physical properties of iPP was studied using various analytical techniques including water contact angle (WCA), attenuated total reflection (ATR), Raman spectroscopy, X-ray diffraction (XRD), and atomic force microscopy (AFM). The results indicate that the hydrophilicity and the C=O bonds of the treated iPP were improved as observed, respectively, through WCA and FTIR analysis. The crystal structure was evaluated by Raman spectroscopy and XRD. It was found that the iPP chain was under microscopic stress, which affects its crystallinity degree depending on the duration of the treatment. Furthermore, the AFM analysis revealed that the surface roughness was substantially modified.

Impact of PCBM as a Third Component on Optical and Electrical Properties in Ternary Organic Blends.

This paper investigates the influence of constituent weight ratios on optical and electrical properties, with a particular focus on the intrinsic properties (such as electrical mobility) of ternary organic blends, highlighting the role of a third component. The study explores novel donor:acceptor1:acceptor2 (D:A1:A2) matrix blends with photovoltaic potential, systematically adjusting the ratio of the two acceptors in the mixtures, while keeping constant the donor:acceptor weight ratio (D:A = 1:1.4). Herein, depending on this adjustment, six different samples of 100-400 nm thickness are methodically characterized. Optical analysis demonstrates the spectral complementarity of the component materials and exposes the optimal weight ratio (D:A1:A2 = 1:1:0.4) for the highest optical absorption coefficient. Atomic force microscopy (AFM) analysis reveals improved and superior morphological attributes with the addition of the third component (fullerene). In terms of the electrical mobility of charge carriers, this study finds that the sample in which A1 = A2 has the greatest recorded value [μmax=1.41×10-4cm2/(Vs)]. This thorough study on ternary organic blends reveals the crucial relationship between acceptor ratios and the properties of the final blend, highlighting the critical function of the third component in influencing the intrinsic factors such as electrical mobility, offering valuable insights for the optimization of ternary organic solar cells.

Investigations on the Impact of a Series of Alkoxysilane Precursors on the Structure, Morphology and Wettability of an Established Zirconium-Modified Hybrid Anticorrosion Sol-Gel Coating.

The current study reports on the impact of a series of functional alkoxysilanes on the wettability and structure of a well-established silicon/zirconium hybrid anticorrosion sol-gel coating. The selected functional alkoxysilanes comprise tetra ethylorthosilicate (TEOS), 3-glycidyloxypropyltrimethoxysilane (GPTMS), 3-aminopropyltriethoxysilane (APTES) and vinyltriethoxysilane (VTES) and are incorporated at various concentrations (1, 5, 10 and 20%) within the silicon/zirconium sol-gel material. The prepared materials are successfully processed as coatings and cured at different temperatures in the range of 100-150 °C. The characterisation of the structures and surfaces is performed by dynamic light scattering (DLS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), silicon nuclear magnetic resonance spectroscopy (29Si-NMR), atomic force microscopy (AFM) and static water contact angle (WCA). Structural characterisations (DLS, FTIR,29Si-NMR) show that the functional alkoxysilanes effectively bind at the surface of the reference sol-gel material, resulting in the formation of functional core-shell nanoparticles. WCA results show that the hydrophobic properties of all materials decrease with curing temperature, and AFM analysis demonstrated that this behaviour is associated with a decrease in roughness. The physico-chemical processes taking place are critically assigned and discussed.

Surface topography and surface morphology of graphene nanocomposite by FESEM, EDX and AFM analysis

The analyzed nanocomposites of this research have been fabricated by the sintering method, where different percentages of boron nitride, zinc oxide, aluminum oxide and titanium oxide have reinforced graphene. The percentages of additives were varied from 0 % to 5 %. An investigation of nanostructural observation, phase identification and structural analysis of graphene nanoparticles has been performed using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX) analysis and X-Ray Diffraction (XRD) analysis. The morphology of the synthesized materials was investigated by examining the FESEM pictures at different magnifications. The micrographs depict the hetero-materials' amalgamation, resulting in the formation of compacted particles that collectively exhibit a prominent bulbous morphology. The size and shape of different particles in the nanocomposites are visible from the FESEM images. The assays conducted by EDX have verified the presence of the necessary components, exhibiting a high degree of purity. Further insights about the nanocomposites have been obtained from Atomic Force Microscopy (AFM) analysis. AFM analysis revealed the surface roughness, which increased to 11.9 from 4.4 µm due to the addition of BN. The crystalline structure has been confirmed from the XRD analysis.

Enhancement of Low-Zinc Phosphate Coatings with addition Ni2+ and Mn2+ Cations: Structure, Corrosion Resistance and Paint Adhesion

Multi-cation phosphate coatings are used in various industries today to enhance the properties of the painting process. This study explored the impact of adding nickel and manganese ions to the low-zinc phosphating process on the properties of the resulting coating. The first step of the research examined the influence of the bath phosphating agents’ concentration, temperature and immersion time and pH on the phosphate coating on the steel 41Cr4 substrate. The second step explored the impact of varying concentrations of Zn, Ni and Mn cations in the phosphating bath and the third step compared the characteristics of zinc (single-cation), Zn-Ni (two-cation) and Zn-Ni-Mn (three-cation) phosphate. The surface thickness and weight per unit area of the phosphate coating, the total and free acid values, and the coating morphology and microstructure were measured; corrosion resistance tests including alkali solubility and salt spray tests were conducted. In addition, scratch, impact, hardness and bending tests of the paint layer were performed. The results indicated that introducing Ni2+ and Mn2+ cations into the low-zinc phosphating bath enhances the structure, corrosion resistance and paint adhesion of the phosphate coating. Scanning electron microscope images revealed that the optimal three-cation coating has a cubic and sheeted structure. Atomic force microscope analysis also demonstrated that in the tri-cation phosphate coating, compared to the zinc phosphate coating, the roughness (Ra) decreases by up to 50% and reaches 8.92 nanometers. The optimal three-cation coating has the highest corrosion resistance, which is attributed to the higher uniformity, lower porosity, fine crystalline structure, and high percentage of corrosion-resistant phases in the coating composition. The time to the onset of initial corrosion signs in the salt spray test, both without and with paint, increases by 50% and 225%, respectively, resulting in 11 and 180 hours.

Enhanced stability and bioavailability of mulberry anthocyanins through the development of sodium caseinate-konjac glucomannan nanoparticles

This study was carried out to improve the stability of anthocyanins (ACNs) by developing MA-SC-KGM nanoparticles using a self-assembly method that involved the combination of sodium caseinate (SC) and konjac glucomannan (KGM) with mulberry anthocyanin extract (MA). Atomic force microscopy (AFM) analysis showed SC encapsulated MA successfully. Multispectral techniques demonstrated the presence of hydrogen bonds and hydrophobic interactions in the nanoparticles. MA-SC-KGM ternary mixture improved storage stability, color stability and anthocyanin retention better compared to the MA-SC binary mixture. Notably, MA-SC-KGM nanoparticles significantly inhibited the thermal degradation of ACNs, improved pH stability, and showed stability and a slow-release effect in gastrointestinal digestion experiments. In addition, MA-SC-KGM nanoparticles were effective in scavenging DPPH· and ABTS+ free radicals, with enhanced stability and antioxidant capacity even during the heating process. This study successfully developed a novel MA-SC-KGM protein-polysaccharide composite material that effectively stabilized natural ACNs, expanding the application of ACNs in various industries.

Design and Analysis of Composite Biomaterial Bone Graft Plate

The mixing technique was applied in this study to enhance the strength performance of the cement. The addition of 3% by weight of hydroxyapatite (HA) nanoparticles were mixed with 97% polymethyl methacrylate (PMMA) acrylic polymer, which has a nano size to serve as the matrix material. The surface roughness and continuous porosity of the bone cement were found to be slightly increased by the incorporation of nanoparticles, which enhanced bone-implant osseointegration and ingrowth. Atomic force microscopy (AFM) analysis revealed that the addition of hydroxyapatite (HAp) nanoparticles resulted in a surface roughness value (Sa) of 16.25 nm, which is similar to that of natural bone. The energy-dispersive X-ray spectroscopy (EDS) mapping results discover precentor material and uniform distribution. The Sample exhibited promising results in the antibacterial test, showing efficacy against bacteria both with and without sterilization, confirming its antibacterial properties. The mechanical tests conducted on the sample, including tensile, compression, bending and Vickers hardness tests, yielded favorable results and indicated that the sample is suitable for its intended application. In the theoretical works the design of the bone, screw, and bone plate was conducted using SolidWorks, followed by an analysis using ANSYS under both axial and bending load conditions. The theoretical analysis revealed that the safety factor was less than 1 when an axial load of 13 N was applied and a bending load of 2 N was applied, indicating that the structure may not be able to withstand these loads safely. Under both ambient and physiologically relevant conditions in the human body, HA and PMMA have demonstrated to be excellent choices for enhancing the clinical performance of bone cement. This, in turn, can lead to increased longevity of implants, decreased patient risk, and lower healthcare costs

Influence of Stacking Order on the Structural and Optical Properties of Cu2ZnSnS4 Absorber Layer Prepared from DC-Sputtered Oxygenated Precursors

Several studies have attempted to overcome the sudden volume expansion of the precursor during sulfurization by the use of oxygen-containing precursors when growing the CZTS absorber. This work demonstrates the influence of precursor stacking orders on the properties of the CZTS thin film absorber layer from DC-sputtered oxygenated precursors for solar cell applications. CZTS absorber layers were prepared from three types of DC-sputtered stacks, namely, Zn-O/Sn/Cu, Sn/Zn-O/Cu, and Sn/Cu/Zn-O. The precursors were sequentially deposited on a soda lime glass (SLG) using DC-magnetron sputtering and annealed in a sulfur and nitrogen ambient. X-ray diffractometry (XRD) and Raman spectroscopy analyses reveal the formation of crystalline kesterite CZTS structure regardless of the precursor stacking order. Atomic force microscope (AFM) analysis showed that CZTS thin films grown from precursor stacks SLG/Zn-O/Sn/Cu and SLG/Sn/Zn-O/Cu had improved morphological properties with densely packed large grains compared to that with stack SLG/Sn/Cu/Zn-O. SLG/Zn-O/Sn/Cu is the best stack among the studied stacking orders since it exhibits large grains in the absorber layer, which is preferential for high-efficiency thin film solar cells. The use of oxygenated precursor with order Sn/Zn-O/Cu promises improved CZTS absorber properties as it exhibits better morphological properties.

High Potential Electrochemical Synthesis of Thermally Reduced Graphene Nanomaterial

In this study, we provide electrochemical techniques for synthesizing thermally reduced graphene nanomaterial that have high potential, low defects, cost-effectiveness, and ecological sustainability. The electrochemical exfoliation is carried out by employing a 195 W DC (voltage = 60[Formula: see text]V and current = 3.25 A) power source at a maximum electrolyte temperature of about 92.5∘C within the aqueous suspension of 2[Formula: see text]M of sulfuric acid (H2SO[Formula: see text]. Thereafter, the synthesized nanomaterial was treated in the weak piranha [combination of sulfuric acid and hydrogen peroxide (H2O[Formula: see text]] solution using an electrochemical technique inside the water bath sonicator at 80∘C. X-ray diffraction (XRD) analysis shows the peak of diffraction to the (002) plane of the reduced graphene oxide (RGO) samples emerges at around 2[Formula: see text] and 26.56∘ with an interplanar distance of 3.40 Å and 3.54 Å. According to the XRD data, after the high-temperature thermal reduction phase, the structure of the crystals and interplanar separation were recovered. The size of the crystallite of RGO produced under H2SO4 conditions was discovered to be greater than the crystallite size of graphene oxide produced under piranha solution conditions. The Raman analysis results show that the degree of disorder of the graphene synthesized within the H2O2 was higher than in comparison to the graphene synthesized in H2SO4. Field emission scanning electron microscopy (FE-SEM) results show that graphene synthesized in the presence of H2O2 has a thin and porous microstructure in comparison to H2SO4 with no significant effect on the presence of the availability of the C/O ratio. The atomic force microscopy (AFM) analysis indicates that the surface roughness of the graphene synthesized in the H2O2 was higher than that of the H2SO4. The Fourier transform infrared spectroscopy (FT-IR spectroscopy) analytical results show that the majority of the functional groups have been eliminated within the samples.

UV-mediated photochemical synthesis and investigation of the antiviral properties of Silver nanoparticle-polyvinyl butyral nanocomposite coatings as a novel antiviral material with high stability and activity

Effectively developing new antimicrobial surfaces for viral diseases requires considerable research, money, and time. Moreover, new species of microorganisms and pathogens are constantly appearing or entering from other regions, which can cause epidemics or pandemics. The ongoing presence of SARS-CoV-2 underscores the need to develop new antimicrobial materials. In this context, a novel UV-irradiated photochemical in-situ synthesis method is introduced for producing durable, long-lasting antiviral silver-polymer (AgNP-PVB) nanocomposite coatings. These coatings are intended to mitigate infectious disease transmission across various frequently touched surfaces, such as door handles, keypads, bank encoders, telephone locks, lift buttons, etc. Additionally, the significance of the size and concentration of AgNP in influencing the physical and antiviral properties of these nanocomposite coatings is illustrated. Detailed studies of AgNP-PVB coatings were conducted using X-ray diffraction, Raman spectroscopy, atomic force microscopy (AFM), and ultraviolet-visible-near-infrared spectroscopy, and contact angle measurements. The antiviral properties of the coatings were evaluated by a one-step reverse transcription real-time polymerase chain reaction (one-step qRT‒PCR) using synthetic SARS-CoV-2 RNA. Raman spectra signatures confirm AgNPs in the PVB matrix by matching identified peaks in X-ray diffractograms. AFM analysis revealed a reduction in AgNP size in the nanocomposite with an increase in the irradiation duration from 5 to 30 min. Spectroscopic results corresponding to AFM measurements highlighted specific wavelengths related to different AgNP size ranges. Contact angle measurements suggest that antiviral activity can be predicted by calculating the surface free energy (SFE) of the sample. As the SFE value increases, antiviral activity decreases. Nanocomposite coatings (with concentrations of 150, 200, 500, and 1000 ppm AgNP) are effective in reducing the activity of SARS-CoV-2, indicating their potential as long-acting preventive agents against viral infections. A methodology incorporating a specialized algorithm was devised for the application of the investigated coatings, which also integrates 3D scanning and printing techniques for fabricating complex geometry flexible protective cover. Subsequently, this coating was applied to produce a protective cover for the widely utilized public object, the door handle, employing 3D printing technology. As a result of the work, a long-term, durable antiviral AgNP-PVB nanocomposite coating with varying AgNP sizes (ranging from 15 to 118 nm) and concentrations (150, 200, 500, and 1000 ppm) was successfully developed.

Assessment of sealing efficacy, radiopacity, and surface topography of a bioinspired polymer for perforation repair.

Root perforation repair presents a significant challenge in dentistry due to inherent limitations of existing materials. This study explored the potential of a novel polydopamine-based composite as a root repair material by evaluating its sealing efficacy, radiopacity, and surface topography. Confocal microscopy assessed sealing ability, comparing the polydopamine-based composite to the gold standard, mineral trioxide aggregate (MTA). Radiopacity was evaluated using the aluminium step wedge technique conforming to ISO standards. Surface roughness analysis utilized atomic force microscopy (AFM), while field emission scanning electron microscopy (FESEM) visualized morphology. The polydopamine-based composite exhibited significantly superior sealing efficacy compared to MTA (P < 0.001). Radiopacity reached 3 mm aluminium equivalent, exceeding minimum clinical requirements. AFM analysis revealed a smooth surface topography, and FESEM confirmed successful composite synthesis. This study demonstrates promising properties of the polydopamine-based composite for root perforation repair, including superior sealing efficacy, clinically relevant radiopacity, and smooth surface topography. Further investigation is warranted to assess its clinical viability and potential translation to endodontic practice.

Development of VEGF mimetic QK peptide on polycaprolactone nanofiber for vascular tissue engineering

Electrospinning allows promoting vascular tissue formation. Polycaprolactone (PCL) is a promising polymer for vascular tissue engineering because of its great mechanical strength and efficient fabrication. However, PCL shows limited biocompatibility owing to its hydrophobic structure. PCL nanofibers can be modified by peptides to improve biological activity. KLTWQELYQLKYKGI (QK) is a peptide that mimics the Vascular Endothelial Growth Factor (VEGF) by organizing endothelial cells. It is critically important to identify the optimum concentration of QK peptide conjugation onto PCL nanofiber for vascularization. Thus, PCL nanofibers were conjugated by different QK peptide concentrations (10 µM, 100 µM and 1000 µM). QK conjugated nanofibers were characterized by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) analysis. The vascularization was evaluated by Live and Dead staining assay, real time PCR of platelet/endothelial cell adhesion molecule (PECAM-1), VEGF and vascular endothelial-cadherin (VE-cadherin) genes and VEGF immunofluorescence analysis. The surfaces of PCL nanofibers were modified by different concentrations of QK peptide. The roughness of nanofibers increased depending on the increased concentration of QK peptide. The higher cell attachment and cell viability were observed in 1000 µM of QK peptide. 1000 µM of QK peptide showed higher vasculogenic potential in terms of PECAM, VEGF, and VE-cadherin gene expression than all the other experimental groups. In the same on gene expression analysis by qPCR, 1000 µM concentration of QK peptide showed the higher VEGF protein than the other experimental groups. 1000 µM concentration of QK peptide can be used to improve the vasculogenic property of PCL nanofibers.

Enhancing CFRP laminates with plasma jet arrays: A study of interlaminar mechanical properties

AbstractThis study delves into the efficacy of plasma jet array treatment in bolstering the interlaminar toughness of Carbon Fiber Reinforced Polymer (CFRP) prepregs, a crucial parameter for their deployment in high‐performance domains. Employing high‐frequency pulsed microsecond plasma jet arrays for surface modification, this research not only demonstrated a 19.49% upsurge in peak load capacity but also a remarkable 29.94% enhancement in Mode I interlaminar fracture toughness, as evident from Double Cantilever Beam (DCB) tests. Furthermore, the surface wettability improvements were underscored by a substantial decrease in water contact angle from 108.33° to 31.45° and a total surface energy augmentation from 12.20 to 64.16 mN/m, post a 1‐min plasma treatment. X‐ray Photoelectron Spectroscopy (XPS) results indicated an appreciable rise in oxygen functionalities, suggesting enhanced resin‐fiber bonding. Additionally, Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) analyses revealed notable decreases in surface roughness and microscale defects, contributing to smoother surfaces conducive to better adhesive bonding and reduced manufacturing defects. These multifaceted improvements, stemming from alterations in surface chemistry and topography, underpin the significant potential of plasma treatment in advancing CFRP laminate applications requiring superior durability and mechanical resilience.Highlights A plasma jet arrays method to enhance CFRP's interlaminar properties was studied. The influence mechanism of plasma modification was revealed in detail. The interlayer toughening mechanism of CFRP after plasma modification is proposed.

Fundamental Origin of Si Surface Defects Caused by Laser Irradiation and Prevention of Suboxide Formation through High Density Ultrathin SiO2

This research investigates surface damage in electronic devices from laser irradiation, particularly focusing on voids, cracks, and vacancies. We discovered that applying a high-density ultrathin SiO2 layer effectively prevents such defects. Atomic Force Microscopy (AFM) analysis showed a significant reduction in surface roughness, with the Rq factor value dropping to 0.158 nm in samples coated with this SiO2 layer. Additionally, X-ray Photoelectron Spectroscopy (XPS) was used to study suboxide formation in the Al2O3/Si structure, revealing insights into defect origins. Electrical tests indicated a substantial decrease in laser-induced damage, evidenced by a leakage current density reduction to 2.4 × 10−6 A/cm2, markedly lower than uncoated samples. Post-metallization annealing (PMA) further improved results, with the interface state density decreasing to 0.63 × 1012 atoms eV−1 cm−2. Our findings highlight the effectiveness of the high-density ultrathin SiO2 layer in mitigating surface defects caused by continuous wave (CW) laser irradiation, promising significant advancements in electronic device manufacturing through potential application in CW laser annealing processes.

Correlating macroscopic plant growth parameters to nanomechanical properties of cellulose microfibrils

The plant cell wall, a vital component in providing structural integrity and facilitating growth, comprises cellulose microfibrils among its major constituents. This study employed Atomic Force Microscopy (AFM) to investigate the intricate relationship between genetic mutation, cellulose microfibril organization, nanomechanical properties of cellulose microfibrils and plant growth. Focusing on the Arabidopsis thaliana wild type (WT) and ixr1–2 mutant population (known for resistance to herbicide ISOXABEN), we utilized AFM to scrutinize cellulose microfibrils on the newly synthesized cell wall in 5-day-old dark-grown hypocotyls. Our macroscopic analysis revealed significant differences in plant growth, prompting a detailed examination at the nanoscale using AFM to discover if the macroscopic disparity between these two populations gets translated in structural details, orientation, and mechanical properties of cellulose microfibrils at the nanoscale too. AFM analysis highlighted distinct organizational disparities in cellulose microfibrils between the WT and mutant population. Our results revealed that the WT manifests a more aligned and oriented microfibril structure in contrast to the mutant population that shows significantly less aligned cellulose microfibrils in the plant growth direction. Also, the WT and mutant population demonstrate nuanced differences in height, width, roughness, deformation, and stiffness. The observed nanoscale alterations in microfibril structure and nano-mechanical properties contribute to an improved understanding of the intricate dynamics governing plant cell wall structure and its pivotal role in growth and development.

Modeling Nonlinear Dynamics of Functionalization Layers: Enhancing Gas Sensor Sensitivity for Piezoelectrically Driven Microcantilever.

This article presents a parametrized response model that enhances the limit of detection (LOD) of piezoelectrically driven microcantilever (PD-MC) based gas sensors by accounting for the adsorption-induced variations in elastic properties of the functionalization layer (binder) and the nonlinear motional dynamics of the PD-MC. The developed model is demonstrated for quantifying cadaverine, a volatile biogenic diamine whose concentration is used to assess the freshness of meat. At low concentrations of cadaverine, an increase in the resonance frequency is observed, contrary to the expected reduction due to mass added by adsorption. The study explores the variations in the elastic modulus vis-à-vis the adsorbed mass of cadaverine and derives the resonance frequency to the adsorbed mass response function. We advance a blended technique involving the analysis of atomic force microscopy (AFM) force-distance (f-d) curves and fitting of the quartz crystal microbalance (QCM) impedance response spectrum to deduce the adsorption-induced changes in the viscoelastic properties of the functionalization layer. The findings obtained are subsequently employed in modeling the response function for a structurally nonhomogenous PD-MC, highlighting the significance of the functionalization layer to the global elastic properties. The structural composition of the PD-MC beam adopted herein features a trapezoidal base hosting the actuating piezoelectric stratum and a rectangular free end with a functionalization layer. The Euler-Bernoulli beam theory coupled with Hamilton's principle is used to develop the equation of motion, which is subsequently discretized into a set of nonlinear ordinary differential equations via Galerkin expansion, and the solutions to the first fundamental mode of vibration are determined using the method of multiple scales. The obtained solutions provide a basis for deducing the nonlinear response function model to the adsorbed mass. The derived model is validated by recorded resonance frequency changes resulting from exposure to known concentrations of cadaverine. We demonstrate that the increase in resonance frequency for low concentrations of cadaverine is due to the dominance of the variation of the elastic modulus of the functionalization layer originating from the initial binder-analyte interactions over damping due to added mass. It is concluded that the developed nonlinear response function model can reliably be used to quantify the cadaverine concentration at low concentrations with an elevated Limit of Detection.

Effect of In-Situ H Doping on the Electrical Properties of In2O3 Thin-Film Transistors

In this article, this research demonstrates the influence of in-situ introduction of H2 into the working gas on the physical properties of post-annealed In2O3 thin films and the performance of associated devices. A gradual increase in the H2 ratio leads to improved film quality, as indicated by spectroscopic ellipsometry, X-ray photoelectron spectroscopy, and atomic force microscope analyses showing a reduction in defect states such as band-tail states and VO in the film, and a smoother surface morphology with the root mean square roughness approximately 0.446 nm. Furthermore, this hydrogen doping effect results in a distinct shift in the device’s threshold voltage toward the positive direction, and an improvement in the field-effect mobility and subthreshold swing. Consequently, a high-performance In2O3:H TFT is developed, exhibiting a field-effect mobility of 47.8 cm2/Vs, threshold voltage of −4.1 V and subthreshold swing of 0.25 V/dec. These findings highlight the potential of in-situ H doping as a promising approach to regulate In2O3-based TFTs.

Highly Transparent and Flexible Multi‐Walled Carbon Nanotubes‐Polyimide Films with Enhanced Electrical Performance as Promising Electrodes

AbstractTransparent and light films with high electrical conductivity are preferred for flexible electronic applications. In this work, a film exhibiting high transparency, electrical conductivity, and flexibility is produced using a polyimide (PI) substrate and multi‐walled carbon nanotubes (MWCNTs) through spray coating. Cost‐effective MWCNTs are used instead of other electrically conductive materials, including silver nanowire (AgNW) ink, SWCNTs, and other carbon materials. The average sheet resistance of the prepared MWCNT‐PI film is 520.2 Ω/□ (infinite for the bare PI film), which is lower than the sheet resistances of the SWCNT‐PI film reported by another group. This could be attributed to the increase in electrical conductivity of the highly transparent PI film due to the use of MWCNTs. The transparency of the MWCNT‐PI film is 71.834% at 550 nm. When MWCNTs and PI are combined, MWCNTs protrude from the surface of the PI film, creating networks and increasing electrical conductivity. Atomic force microscopy analysis revealed that MWCNT networks formed on the surface of the MWCNT‐PI film. This study suggests the possibility that MWCNTs can also be used as carbon materials for flexible and highly transparent films. Ω/□This article is protected by copyright. All rights reserved