The present competition of graphene electronics demands an efficient route which produces high quality and large area graphene. Chemical vapour deposition technique, where hydrocarbons dissociate in to active carbon species and form graphene layer on the desired metal catalyst via nucleation is considered as the most suitable method. In this study, single layer graphene with the presence of few layer single crystal graphene grains were grown on Pt foil via chemical vapour deposition. The higher growth temperature changes the surface morphology of the Pt foil so a delicate process of hydrogen bubbling was used to peel off graphene from Pt foil samples with the mechanical support of photoresist and further transferred to SiO2/Si substrates for analysis. Optical microscopy of the graphene transferred samples showed the regions of single layer along with different oriented graphene domains. Two type of interlayer stacking sequences, Bernal and twisted, were observed in the graphene grains. The presence of different stacking sequences in the graphene layers influence the electronic and optical properties; in Bernal stacking the band gap can be tunable and in twisted stacking the overall sheet resistance can be reduced. Grain boundaries of Pt provides low energy sites to the carbon species, therefore the nucleation of grains are more at the boundaries. The stacking order and the number of layers in grains were seen more clearly with scanning electron microscopy. Raman spectroscopy showed high quality graphene samples due to very small D peak. 2D Raman peak for single layer graphene showed full width half maximum (FWHM) value of 30cm−1. At points A, B and C, Bernal stacked grain showed FWHM values of 51.22, 58.45 and 64.72cm−1, while twisted stacked grain showed the FWHM values of 27.26, 28.83 and 20.99cm−1, respectively. FWHM values of 2D peak of Bernal stacked grain showed an increase of 20–30cm−1 as compare to single layer graphene which showed its dispersive nature and confirmed Bernal sequence. On the other hand, the slightest decrease in FWHM values of 2D peak in twisted grain comparing to single layer confirmed the twisted sequence of grains. Atomic force microscopy analysis showed an increasing trend in grain height profile with an increase in the number of layers

We studied the density and aggregation behavior of virions on TCPS and glass substrates, surface functionality, coffee ring effect on both surfaces and the effect of ethanol-based disinfectant on the virion structure using atomic force microscopy.

Reduced graphene oxide (rGO) reinforced copper (Cu) matrix composites were produced using arc induction melting (AIM) to investigate the microstructural, mechanical, tribological, and electrical responses of the system. rGO additions of 0.5 and 1.0 wt% were introduced to clarify interfacial strengthening and functional synergies within the Cu matrix. Characterization through X‐ray Diffraction, Scanning Electron Microscopy, Energy‐Dispersive X‐ray Spectroscopy, Atomic Force Microscopy, and Lateral Force Microscopy confirmed homogeneous rGO dispersion, refined grain structure, and the absence of undesirable secondary phases. Incorporating rGO led to a significant increase in hardness, rising from 65 ± 4HV30 for pure Cu to 225 ± 3HV30 for the composite containing 1 wt% rGO. This improvement is associated with Hall–Petch strengthening, Orowan looping, and effective interfacial load transfer. Tribological evaluations demonstrated up to 78% reduction in wear rate and more than 60% decrease in friction coefficient, linked to the formation of a stable, self‐lubricating carbonaceous tribofilm. SEM/EDX analyses of worn surfaces confirmed the presence of a continuous protective carbon layer. Electrical conductivity showed a slight improvement, maintaining the structural integrity of the Cu–rGO interface. Overall, AIM proved to be a scalable and energy‐efficient approach for fabricating dense and multifunctional Cu–rGO nanocomposites suitable for electromechanical and thermal management applications.

Biosensors, while holding immense promise for biomarker detection, face substantial challenges in analytical performance, fabrication intricacies, and complex applications, hindering their seamless integration into point-of-care (POC) settings. Metamaterial-based plasmonic biosensors offer tremendous potential for biomarker detection; however, their widespread adoption in POC diagnostics remains hampered by limitations in sensitivity, fabrication complexity, and production cost. Herein, we introduce, for the first time, in situ-controlled spatial designs on metamaterial-based plasmonic sensors, demonstrating unprecedented sensitivity in detecting extracellular vesicles (EVs). In the fabrication process, commercially available optical disks were repurposed as nanostructured substrates, yielding a cost reduction of up to 260-fold ($0.90 per sensor) and a fabrication time reduction of approximately 960-fold, compared to conventional e-beam lithography. Leveraging inherent nanogratings, measurements are conducted on a compact, palm-sized platform, addressing challenges in usability and portability associated with bulky optical designs. Through ex situ immobilization of gold nanoparticles (AuNPs) or in situ formation of nanoislands (NIs), we have engineered plasmonic hotspots that substantially enhanced local electric field intensities, thereby amplifying the bulk refractive index sensitivity of the sensors. Finite-difference time-domain simulations confirmed that the spatial arrangement and interparticle distances of spatial designs enhance near-field effects. The optimized platform exhibits up to a 5.5-fold enhancement in refractive index sensitivity. Moreover, based on data obtained from nanoparticle tracking analysis (NTA), fluorescence-enhanced NTA (fNTA), and recent literature benchmarks, the platform demonstrated detection limits of 10⁴ particles/μL (as determined by raw NTA measurements), approximately 330 fg/μL (estimated via literature-based EV mass calculations), and 138 EVs/μL (quantified via fNTA using marker-specific labeling). Herein, we anticipate that repurposing disks as metamaterial sensors has the potential to address pressing challenges in usability, portability, cost, and complexity. Besides, 3D configurations on sensors would improve the analytical performance, offering highly sensitive and facile platforms for diverse applications in the future.

Polymeric microparticles have triggered critical advancements in drug delivery systems, offering significant improvements in therapeutic efficacy by controlling the delivery while minimizing adverse side effects of the pharmaceuticals. However, conventional microparticle fabrication techniques face several limitations, such as particle size variability, early drug degradation, and production inefficiencies. In this study, we developed a microparticle production system (MPS) in which a precision spraying technology was integrated with a microfabricated nozzle array-based piezoelectric transducer. High-throughput microparticle production was achieved using Poly(D,L-lactide-co-glycolide) (PLGA) dissolved in dichloromethane (DCM) and dimethyl carbonate (DMC). The resulting PLGA microparticles exhibited remarkable consistency in size uniformity with an average diameter of 8.9 ± 1.7 μm. Detailed characterization through scanning electron microscopy (SEM) and focused ion beam (FIB) analyses revealed distinct surface and internal structures and demonstrated the effect of solvent volatility on microparticle morphology. Chloramphenicol (CHL) was used as a model drug, and an encapsulation efficiency of 38.7% and a loading efficiency of 16.2% were achieved. The PLGA microparticles showed sustained CHL release and demonstrated effective antibacterial activity against Escherichia coli (E. coli), highlighting their potential for controlled therapeutic applications. This developed MPS system offers a scalable and efficient approach for producing PLGA-based microparticles with controlled drug release profiles, making it valuable in the industrial-scale production of advanced drug delivery technologies.

The constructs of lipid molecules follow self-assembly, driven by intermolecular interactions, forming stacking of lipid bilayer films. Achieving designed geometry at nano- to micro-levels with packing deviating from the near-equilibrium structure is difficult to achieve due to the strong tendency of lipid molecules to self-assemble. Using ultrasmall (<fL) droplets containing designed molecules, our prior work has demonstrated that molecular assembly, in principle, is governed mainly by transient inter-molecular interactions under their dynamic spatial confinement, i.e., tri-phase boundaries during drying. As a result, the assemblies can deviate, sometimes significantly, from the near-equilibrium structures of self-assembly. The present work applies the approach and concept to lipid molecules using 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Taking advantage of the high spatial precision and the minute size of the delivery probe in our combined atomic force microscopy and microfluidic delivery, the transient shape of each liquid droplet is regulated. In doing so, the final geometry of the POPC assemblies has been regulated to the designed geometry with nanometer precision. The results extend the concept of controlled assembly of molecules to amphiphilic systems. The outcomes exhibit high potential in lipid-based biomaterial science and biodevice engineering.