Nanomanufacturing, Volume 6, Issue 3 (September 2026) – 10 articles

Historically, TEM prep has been an artisan craft without a systematic workflow that ensures quantified control over TEM sample thickness. Over- and under-thinning is a significant problem in the TEM prep process. A direct measurement process was demonstrated to control the final thickness of the TEM lamella. Final lamella thickness was controlled by directly measuring lamella thickness in real time using a 10–15 kV SEM while performing secondary electron imaging at the mill position, allowing for (human-mediated) closed-loop processing. We demonstrated the utility of this technique by systematically thinning five TEM samples to discretely target thicknesses ranging from 100 nm down to 28 nm. We demonstrated the repeatability and simplicity of the process by fabricating 10 STEM lamella with a targeted thickness of 32 nm. We demonstrate the ability to fabricate an engineered multi-layered structure that acts as a lamella thickness measurement feature that is independent of sample type, allowing a broader implementation of in-line lamella thickness monitoring. We applied our thickness measurement technique to three thin-film materials (Au, Ag, and Cu) to obtain TEM lamella thickness target values needed to achieve electron transparency for each material. Having knowledge of a target thickness parameter prevents the over- and under-thinning problem in TEM prep. Full article

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