Nanomanufacturing

The development of flexible thin-film transistors (TFTs) is crucial for the advancement of wearable electronics, bendable displays, and the Internet of Things (IoT). A key challenge in this field is the fabrication of high-performance gate dielectric layers that combine excellent electrical properties with mechanical robustness and low-temperature processability. In this work, we report flexible TFTs based on CdS and hybrid PVPh/PMMA-ZrO₂ as semiconductor and gate dielectric layers, respectively. The hybrid gate dielectric films were deposited on flexible PEN substrates via a facile spin-coating process at a low temperature of 150 °C. On the other hand, CdS layers were deposited through photo-assisted chemical bath deposition at room temperature. Both correspond to deposition methods in solutions, fulfilling the low-temperature condition. The electrical properties of the hybrid gate dielectric layers were characterized by using metal–insulator–metal (MIM) capacitors, which presented excellent insulating properties, low leakage current density and suitable gate capacitance for transistor operation. From the analysis of the electrical response of flexible TFTs, reliable device characteristics and key electrical metrics were extracted. Furthermore, the MIM and TFTs were tested under mechanical bending, demonstrating stable performance. The MIM capacitors showed outstanding mechanical stability, retaining low leakage and stable capacitance after 1000 bending cycles, with changes attributed to reversible interfacial charge redistribution rather than bulk degradation. Meanwhile the TFTs kept full electrical functionality under repeated bending and tight bending radii (down to 0.6 cm), demonstrating reasonable mechanical durability. These results validate the solution-processed PVPh/PMMA-ZrO₂/CdS system as a promising, mechanically robust platform for flexible electronics. Full article

Bismuth oxybromide (BiOBr), a layered semiconductor with good photogenerated carrier separation, is valuable for visible-light organic pollutant degradation. However, traditional hydrolysis-synthesized BiOBr has uneven particles, agglomeration, and insufficient active sites, limiting performance. This study used a microwave–hydrothermal method (adjusting time, temperature, power, pH) to prepare nanosheet-assembled BiOBr, characterized via XRD, SEM, Raman, and XPS. Under light irradiation, BiOBr primarily degrades Rhodamine B through direct oxidation by highly oxidative photogenerated holes, supplemented by the auxiliary oxidation of superoxide radicals. While maintaining a consistent catalyst loading, the optimal experimental conditions were applied (140 °C, 400 W, 10 min); 50–60 nm thick BiOBr achieved 95.4% RhB degradation (k = 0.03174 min⁻¹) in 100 min, far better than traditional BiOBr (61.16%, k = 0.00917 min⁻¹). This proves the method optimizes BiOBr performance. Full article

This study explores the direct synthesis of carbon nanostructures on AISI 1018 low-carbon steel via spray pyrolysis, using α-pinene—a turpentine-derived terpene—as a sustainable carbon source. Two synthesis routes were evaluated: a catalyst-aided approach using ferrocene and a catalyst-free approach. Both methods yielded homogeneous coatings; however, the addition of ferrocene produced carbon nanotube (CNT) films (~70 μm), while the catalyst-free method resulted in carbon nanofiber (CNF) films (~50 μm). Tribological testing revealed that CNF coatings maintained a consistently low friction coefficient of ~0.12. In contrast, CNT coatings exhibited higher friction, increasing from 0.15 to 0.35 under loads of 2–5 N. SEM and Raman spectroscopy of the wear tracks suggest that CNFs retain their crystalline structure during friction, whereas CNTs become increasingly defective, leading to higher friction levels. Full article

This paper describes a three-dimensional simulation of electron transmission through a nanoscale transistor using the finite-difference time-domain (FDTD) method. The simulation begins by defining a wave packet that represents an electron at the transistor’s source, followed by modeling the electron’s interaction as it traverses the transistor’s channel to the drain. The software tools employed in this study implement a fully three-dimensional solution to the time-dependent Schrödinger equation, using finite-difference approximations for both temporal and spatial derivatives. The analysis of electron transmission enables the generation of current-voltage (I–V) characteristics under various gate and drain-source voltage conditions. Although the simulations focus on the dynamics of a single electron, the methodology can be extended to accommodate multi-electron systems through the incorporation of density functional methods. Full article

Recent demand for reliable, low-power, and cost-effective gas sensors has spurred research into chemiresistive materials that operate under ambient conditions. PEDOT and PEDOT:PSS combined with semiconductor metal oxides (SMOs) have attracted attention due to their complementary properties: polymer flexibility and stability, alongside oxide reactivity and robustness. This review highlights the integration of PEDOT and PEDOT:PSS with n- and p-type SMOs, concentrating on fabrication techniques, sensing mechanisms, and performance indicators, such as sensitivity, selectivity, and response time. Emphasis is placed on heterojunction engineering, morphology control, and the influence of particle size and environmental factors. Despite notable progress, challenges persist in long-term stability, selectivity in mixed gases, and performance under varying conditions. Interface engineering and composite optimisation show promise, with potential applications in environmental monitoring, industrial safety, and wearable diagnostics. Full article

This study investigates the enhancement of electrical conductivity in poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) thin films through the incorporation of few-layer graphene (mG). Nanocomposite films were prepared by spin coating from liquid dispersions containing approximately 10 wt% mG. The resulting films exhibited high optical transmittance (~80%) and significantly reduced sheet resistance, reaching values as low as 1.8 kΩ/□. These improvements in electrical and optical performance are attributed to enhanced charge transport arising from π–π interactions between graphene and PEDOT:PSS, as well as conformational changes in the polymer chains. The PEDOT:PSS/mG composites were successfully applied both as conductive inks, forming conductive trails capable of powering a light-emitting diode (LED), and as hole transport layers in organic light-emitting diodes (OLEDs). Comprehensive optical and electrical characterization of the composite films and the corresponding OLED devices demonstrates the strong potential of PEDOT:PSS/mG nanocomposites for use in flexible and printed electronic applications. Full article

The increasing demand for materials with enhanced properties and high-performance devices has driven substantial research into nanomanufacturing, particularly using carbon nanotubes (CNTs), because of their exceptional properties and high sensitivity to chemical doping. In this way, this work summarizes nanomanufacturing methods for CNT-based devices developed in Brazil, covering the complete cycle from nanocomposite production to functional device assembly across cellulosic, polymeric, and metallic matrix systems. For cellulosic matrices, vacuum filtration enables the production of buckypaper, which is subsequently assembled into chemiresistive, thermoresistive, and thermoelectric devices. For polymeric matrices, 3D printing combined with surface functionalization techniques (spray coating, inverted immersion, and direct immersion) produces piezoresistive robotic sensors, metal-free thermal sensors, and biomedical scaffolds for tissue engineering. For metallic matrices, electrodeposition can produce Cu-CNT-coated aluminum comparable to traditional copper power transmission cables, while arc welding produces stainless steel composites with properties comparable to commercial high-grade steels. These devices have commercial and industrial applications, with low-cost and scalable production methods in comparison with conventional materials. Characterization results demonstrate that CNT integration into diverse matrices successfully bridges nanoscale properties to macroscopic functional devices. Current challenges include uniform CNT dispersion and structural defect control, laboratory to industry scale transition, and long-term device stability under environmental conditions. Future perspectives encompass lab-on-chip systems, wearable devices, 3D-printed smart structures, Internet of Things integration, and machine learning-enhanced analytics. Full article

Polydiacetylene (PDA) nanovesicles are widely recognized as versatile chromatic sensing platforms, exhibiting a visible blue-to-red colorimetric transition in response to external stimuli such as temperature, pH, and molecular recognition events. In contrast to the conventional goal of amplifying this chromatic response, this work presents a supramolecular approach to inhibit the α-cyclodextrin (α-CD)-induced colorimetric transition in PDA systems. α-CD is known to interact with PDA vesicles through host–guest inclusion at the vesicle interface, triggering the characteristic chromatic change. Here, we show that the incorporation of an EO–PO–EO triblock copolymer (L64) into PDA suspensions enables controlled modulation of the α-CD-induced chromatic response, leading to a progressive attenuation of the blue-to-red transition as the L64 concentration increases. Isothermal titration calorimetry reveals a stronger affinity of α-CD for L64 (K = 11,300) than for PDA vesicles (K = 4000), with both interactions being spontaneous (ΔG° ≈ −21 kJ mol⁻¹) and predominantly entropy-driven. Copolymer aggregation and phase separation occur without compromising the PDA vesicles, indicating that the observed chromatic modulation arises from supramolecular competition. This study introduces a strategy to regulate PDA affinity chromism using biocompatible triblock copolymers, offering a tunable and robust pathway for the design of responsive and safe chromatic sensing platforms. Full article

Rapid detection of heavy metals is vital for monitoring surface water contamination and preventing environmental and health risks. Traditional detection methods for metals such as lead and copper often require sophisticated, costly instrumentation, limiting their use in routine analyses. To address this challenge, we developed a cost-effective fluorescence-based approach using semiconductor quantum dots (QDs) as nanosensors for metal ion detection. The QDs were synthesized directly in aqueous medium through a reflux-assisted process employing cadmium precursors, selenium, thioglycolic acid (TGA), and branched polyethyleneimine (PEI, Mw ~25,000) as stabilizing agents. Structural analysis revealed nanoparticles with diameters below 5 nm, spherical morphology, and a zinc blende (face-centered cubic) crystalline structure. Optical characterization by UV–Vis, photoluminescence (PL), and FTIR spectroscopy confirmed effective surface functionalization and strong quantum confinement. PEI-capped QDs exhibited enhanced colloidal stability and showed pronounced fluorescence quenching in the presence of Pb²⁺ ions, indicating high sensitivity and selectivity toward lead. Both TGA- and PEI-capped QDs also demonstrated moderate responses to Co²⁺ but negligible interaction with Sn²⁺, confirming ion-specific detection. Overall, this study demonstrates that surface-engineered QDs constitute a simple, accessible platform for selective detection of toxic metals, with promising applications in environmental monitoring and water quality assessment. Full article

Additive manufacturing by stereolithography (SLA) is widely used for fabricating complex polymeric parts. However, photocurable resins typically exhibit brittle behavior. In this context, the incorporation of nanofillers has emerged as a strategy to tailor mechanical performance, although challenges related to dispersion and processability remain. This work investigates the co-incorporation of graphene oxide (GO) and kraft lignin, including a low-molecular-weight fraction (FKL), into acrylate-based photocurable resins processed by SLA. Pre-curing dispersion and viscosity were evaluated by optical microscopy and rotational rheometry. The mechanical, viscoelastic, and fracture behavior of the printed nanocomposites was assessed by tensile testing, dynamic mechanical analysis, and scanning electron microscopy. The results show that all formulations exhibited viscosities suitable for SLA processing. The presence of FKL promoted improved GO dispersion and more stable rheological behavior compared with unfractionated lignin. At low lignin contents, a pronounced synergistic effect with GO led to enhanced tensile strength, whereas increasing lignin content reduced stiffness and glass transition temperature while significantly increasing elongation at break, particularly for FKL-based systems. Overall, these findings demonstrate that lignin fractionation is an effective strategy to modulate dispersion, mechanical response, and toughness in GO-containing photocurable resins. Full article

Since the first successful synthesis of borophene in 2015, this atomically thin boron allotrope has attracted extensive attention due to its polymorphic structures, metallic conductivity, and outstanding mechanical flexibility. As a new member of the two-dimensional (2D) materials family, borophene exhibits a unique triangular lattice with tunable hexagonal vacancies, leading to rich structural diversity and anisotropic physical properties. Recent breakthroughs in synthesis—particularly molecular beam epitaxy (MBE), chemical vapor deposition (CVD), and solvothermal-assisted liquid-phase exfoliation (S-LPE)—have significantly expanded the accessible structural phases and improved control over film quality and stability. Meanwhile, borophene’s distinctive combination of structural and electronic characteristics has enabled its rapid development in both energy and biomedical applications. In energy storage, borophene serves as a promising anode material for lithium/sodium-ion batteries and a lightweight medium for hydrogen storage and supercapacitors, owing to its metallic conductivity, high surface charge density, and large adsorption capacity. In biomedicine, borophene-based nanoplatforms exhibit excellent photothermal conversion efficiency, enabling multifunctional roles in cancer diagnosis and therapy. Despite these advances, several challenges—such as environmental instability, oxidation susceptibility, and limited scalable synthesis—continue to restrict practical implementation. Future progress will depend on chemical functionalization, surface passivation, and machine-learning-assisted materials design to achieve oxidation-resistant, large-area, and biocompatible borophene derivatives. This review summarizes recent advances in borophene synthesis, structural engineering, and multifunctional applications, while outlining key scientific challenges and future opportunities for the realization of borophene-based materials in next-generation energy and biomedical systems. Full article

Electrospun composites are desirable materials for drug delivery applications. Regarding microbial infections as a case study, the antibacterial effect is enhanced by physical attributes of electrospun meshes, namely, a high surface area-to-volume ratio and porosity, 3D topography, and customized surface functions. Beyond mimicking nanostructured fibers, the delivery of antibiotics from such composites enhances antibacterial efficacy, sustained release kinetics, and reduced wound infection while minimizing side effects. Concern over antibiotic resistance and the insufficient availability of pharmaceutical agents for effective infection treatment is increasing worldwide. A significant number of publications have reported the fabrication of electrospun composites to mitigate bacterial pathogenesis. However, from a structural and morphological perspective, the implications of electrospinning approaches for antibiotic delivery have not been reviewed. This proposal presents a comparative study of the different assemblies induced by electrospinning, enabling the development of platforms for administering antibacterial agents. The primary objective is to conduct a comprehensive examination of the considerations involved in electrospinning-based manufacturing of drug delivery systems and antibiotic loading, ensuring a thorough design process that accounts for composite processability, monitoring methods for kinetic behavior analysis and modeling, and biological considerations for pre-clinical in vitro characterization. Full article

The distinct electronic and optical properties of gold nanoparticles (NPs) have made them innovative assets for biomolecular sensing. This review outlines the various gold nanoparticle-based biosensing techniques centred on biomolecule detection and signal relay. We discussed the physical, chemical (Turkevich, Brust, seed-mediated growth, and digestive ripening) and biological syntheses involving bacteria, fungi, and plant extracts. Also discussed were the various ways these techniques affect the shape and functionality of the nanoparticles. Detection techniques are typically classified as the following: colourimetric, fluorescence-based, electrochemical, and surface plasmon resonance (SPR). Colourimetric assays enable visual detection of proteins and oligonucleotides by monitoring gold NP aggregation, while molecular beacons enable precise fluorescent-based detection. Quantitative detection of small molecules and gold NPs can be performed using electrochemical sensing, and biomolecular interactions can be analysed in real time using SPR. With the review focusing on the integration of gold NPs with microfluidics and wearable sensors, this synthesis aims to support the design of more practical, real-world applications of the described techniques. Full article

Aerogels represent an extraordinary class of materials characterized by remarkable properties, including an exceptionally high porosity (approximately 99.8%), minimal weight, extraordinarily low density, low thermal conductivity, a diminished dielectric constant, and a reduced refractive index. These attributes arise from their extensive micro-meter-sized pores. In recent years, there has been a notable surge of interest in carbon or carbon nanotube (CNT) based aerogels due to their compelling potential across various applications, encompassing sensors, energy systems, and catalysis, among others. In the context of our ongoing investigation, we have successfully synthesized lightweight aerogels by incorporating copper and carbon nanotubes (Cu-CNT) through electrospinning. Intriguingly, these aerogels exhibit an electrical conductivity of approximately 0.5 × 103 S/cm, positioning them within the realm of semiconductors. Concurrently, their density measures approximately 1.669 g/c.c (similar to CNTs), underscoring their notably low mass. These semi-conductive aerogels, uniquely characterized by their lightweight nature and expansive surface area (approximately 442 m²/g), manifest considerable potential across a spectrum of applications. This includes catalytic processes, energy storage mechanisms, bio-sensing technologies, thermoelectric systems, and the burgeoning domains of micro and wearable electronics. The distinctive combination of properties within these aerogels augments their suitability for these diverse applications, offering the prospect of innovative and impactful advancements in various scientific and technological arenas. Full article

Hyperspectral sensing allows for the capture of spatially resolved spectral data, a capability critical for applications spanning from remote sensing to biomedical diagnostics. Nevertheless, the widespread adoption of this technology is hindered by the bulk and complexity of traditional systems based on diffractive optics. To overcome these hurdles, substantial research efforts have been dedicated to system miniaturization via component scaling and computational imaging. This review outlines the technological progression of compact hyperspectral imaging, ranging from miniaturized dispersive elements and tunable filters to computational snapshot designs using optical multiplexing. Although these approaches decrease system volume, they generally treat the sensor as a passive intensity recorder requiring external encoding. Therefore, we focus here on the rising paradigm of sensor-level integration made possible by nanomanufacturing. We examine optics-free architectures where spectral discrimination is embedded directly into the pixel, distinguishing between pixel-level nanophotonic filtering and intrinsic material-based selectivity. We specifically highlight emerging platforms such as compositionally engineered and cavity-enhanced perovskites, as well as electrically tunable organic or two-dimensional (2D) material heterostructures. To conclude, this review discusses persistent challenges regarding fabrication uniformity and stability, providing an outlook on the future of scalable and fully integrated hyperspectral vision systems. Full article

Simultaneous hydrogen fuel and value-added chemical production from renewable resources is a key strategy in sustainable catalysis. This work presents a novel strategy employing metal–organic frameworks (MOFs) as precursors for synthesizing advanced titanium dioxide (TiO₂) photocatalysts with enhanced structural and optical properties. Two photocatalysts, M-BDC and M-2,5PDC, were synthesized via controlled calcination of MIL-125(Ti) using terephthalic and 2,5-pyridinedicarboxylic acids, respectively. Characterization confirmed the formation of mixed anatase/rutile TiO₂ phases with mesoporous structures. Notably, nitrogen incorporation in M-2,5PDC reduced the optical band gap to 2.94 eV compared with 3.08 eV for M-BDC, enhancing visible-light absorption. Photocatalytic experiments conducted at near-neutral pH (6.0) demonstrated effective simultaneous glycerol oxidation and hydrogen evolution without the use of alkaline additives. M-BDC achieved 30% glycerol conversion with 78.85% selectivity toward dihydroxyacetone and 21.15% toward glyceraldehyde, while M-2,5PDC exhibited selectivities of 71.55% and 28.45%, respectively. Glycerol underwent partial oxidation without complete mineralization, generating high-value products in parallel with hydrogen production. Both catalysts displayed excellent reuse stability across three consecutive cycles, with M-BDC showing enhanced dihydroxyacetone selectivity (78.85% to 84.42% between cycles). This MOF-derived TiO₂ platform integrates controlled synthesis, near-neutral pH operation, high selectivity, and catalytic stability, thereby establishing a viable strategy for the simultaneous production of clean fuel and value-added chemicals from renewable resources. Full article

TiO₂ films with a thickness of 20 nm were obtained by anodizing a titanium film with an aluminum sublayer on a glass substrate. The I–V characteristics were studied in a temperature range of 100–300 K. Three linear sections can be distinguished on the I–V curves in logarithmic coordinates with a bias voltage of up to 2.5 V. The first section is an ohmic section with a bias voltage sweep from 0 V. The second section is associated with the space-charge-limited currents. The third section is characterized by the flow of Poole–Frenkel currents. In the third section, the slope of the approximating line is greater than in the second one due to the flow of higher currents. This is explained by the transition of electrons from donor centers to trap levels, which leads to a decrease in the number of free traps available for capturing electrons injected from the contacts into the conduction band. The obtained values of the Fermi energy of 0.032 and 0.028 eV for temperatures from 100 to 300 K, respectively, indicate that the electron traps in the forbidden zone of TiO₂ are shallow. The value of the donor level energy E = 0.082 eV is close to the values of the activation energy of thermal conductivity. This indicates the formation of donor centers in anodic TiO₂ by the mechanism of donor vacancies. In anodic TiO₂ films, the concentration of electron traps is 10¹⁵ cm⁻³, which is approximately three orders of magnitude less than their concentration in anodic TiO₂ films obtained by vacuum deposition. Full article

In recent years, antiferromagnetic kagome materials have attracted considerable attention in condensed matter physics owing to their distinctive lattice geometry. In this work, high-quality single crystals of D019-structured Mn_2.16Ga were grown using the flux method, and their magnetotransport properties were systematically studied. Measurements of magnetization versus field (M–H), temperature-dependent magnetization (M–T), and the anomalous Hall effect confirm that the crystal undergoes a magnetic-structural transition driven by both temperature and the magnetic field. Remarkably, a coexistence of positive and negative longitudinal magnetoresistance (MR) is observed in Mn_2.16Ga. The MR shows a field-induced sign change from negative to positive. The negative MR is attributed to field-modified magnetic ordering, whereas the positive MR originates mainly from interlayer electron conduction in the kagome lattice and distortion of the in-plane triangular arrangement of Mn magnetic moments. These results offer valuable insights into the electronic and magnetic transport behavior of Mn-based antiferromagnetic single crystals. Full article

Although recycled poly(ethylene terephthalate) (rPET) is an attractive, sustainable feedstock for electrospinning, optimization of processing variables for filtration performance remains limited. This study quantifies how polymer concentration, flow rate, and applied voltage govern fiber morphology and key filtration metrics—collection efficiency (η), pressure drop (ΔP), quality factor (Q_f), and porosity—in rPET membranes. A fractional factorial design was employed to model interactions and identify trade-offs in filtration performance. The optimal condition was obtained at 16 wt.% PET, 1.2 mL·h⁻¹, and 22 kV, yielding uniform fibers with an average diameter of 328.6 nm and high filtration efficiencies (95.65–99.99%). The permeability constants were 1.07 × 10⁻¹² m² (20 wt.% PET) and 1.15 × 10⁻¹³ m² (8 wt.% PET), indicating an increase in permeability with increasing polymer concentration and fiber diameter. The 20 wt.% PET membrane delivered the highest Q_f of 0.0646 Pa⁻¹ with a low ΔP of 48.5 Pa at 4.8 cm·s⁻¹, reflecting a favorable balance between collection and airflow resistance. In summary, higher PET concentrations reduce flow resistance and improve Q_f, whereas lower concentrations yield finer fibers and high η at the expense of permeability. rPET nanofiber membranes, therefore, represent a sustainable and versatile route to high-efficiency, lower-pressure-drop air filters for residential, industrial, and commercial environments. Full article