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Microfluidic paper-based analytical devices (μPADs) and microfluidic thread-based analytical devices (μTADs) have recently been introduced as a new class of on-site monitoring devices. Creating hydrophilic channels with hydrophobic barriers on papers/threads produces μPADs/μTADs. Fabrication is a crucial step in creating durable μPADs/μTADs that can withstand various liquids and impact the device's performance. Fabrication materials with distinct physicochemical properties allow microfluidic systems with sophisticated functions to be customized for specific applications. We present flexible and low-cost fabrication methods for μPAD and μTAD platforms. Platform designs and fabrications were implemented using a trial-and-error method for various designs with varying parameters. All production methods presented in the method section were used in |PAD production. For comparison studies, only the dipping method was used in μTAD production due to its ease of application. In this study, we tried to reveal the strengths and weaknesses of the production techniques and the resulting microfluidic platforms. A leaching test was performed with water solutions containing red ink. The compatibility of the hydrophobic walls of the platforms was tested with several solvents (isopropanol, methanol, and acetone), deionized (DI) water, and phosphate buffer solution PBS and compared. Patterning paper with polydimethylsiloxane (PDMS), white glue, alkyl ketene dimer (AKD), beeswax, and paraffin are much more flexible and simpler than traditional photoresist-based fabrications. The advantages and disadvantages of fabrication techniques; solvent resistance and wicking behaviors of platforms were discussed in the last part. The fabricated microfluidic platforms can be functionalized and used in many areas where analytical tests are applied. Studies on diversifying channel geometries and increasing resolution need to be continued. It should be investigated which devices can be used to obtain qualitative and quantitative results. To make simple and cheap production techniques suitable for mass production, studies should be carried out from different branches. [ABSTRACT FROM AUTHOR]

In this study, graphene‐loaded electrospun recycled poly(ethylene terephthalate) (rPET) nanofibrous mats were produced and characterized morphologically, spectrally, mechanically and thermally. Particularly, the effects of graphene nanoplatelets (GNP) and multilayer graphene (GML) in improving the thermal conductivity and heat dissipation abilities of rPET‐based composite nanofibers were investigated. The morphological analyzes pointed out that 1% graphene loading led to smooth nanofibers while 5 and 10% of GNP‐loading resulted in coarser nanofibers with rougher surfaces and agglomerations. The differential scanning calorimetry results pointed out that the crystallization temperature increased with increasing graphene content as a result of the pronounced nucleation effect. The thermogravimetric analysis demonstrated an improvement in the thermal stability of the composite nanofibers. The thermal conductivity coefficients increased to 25.422 W/mK‐35.842 W/mK for rPET/GNP nanofibers and up to 62.669 W/mK for rPET/GML nanofibers, compared to that of 12.753 W/mK for neat rPET nanofibers which correspond to an increase between 99 and 391%. Heat dissipation capability of the graphene‐loaded composite nanofibers was illustrated with infrared thermography data, displaying an increase in the average surface temperature of the nanofibrous mats between 2 and 19°C at 30 s of heating. The results suggest the use of the graphene‐loaded rPET composite nanofibers as textile materials for thermoregulating applications. Highlights: Recycled poly(ethylene terephthalate)/graphene composite nanofibers are electrospun.Thermal conductivity of graphene‐loaded nanofibers increases by up to 391%.Graphene loading in nanofibers leads to faster and more uniform heat dissipation.Mechanical properties of composite nanofibers improve.Value‐added recycled polyester materials for thermal management are foreseen. [ABSTRACT FROM AUTHOR]

Cadmium-based quantum dots (QDs) are amongst the most studied nanomaterials due to their excellent photophysical properties, which can be controlled by controlling the size and/or composition of the nanocrystal. However, the ultraprecise control over size and photophysical properties of Cd-based quantum dots and developing user-friendly techniques to synthesize amino acid-functionalized cadmium-based QDs are still the on-going challenges. In this study, we modified a traditional two-phase synthesis method to synthesize cadmium telluride sulfide (CdTeS) QDs. CdTeS QDs were grown with an extremely slow growth-rate (growth saturation of about 3 days), which allowed us to have an ultraprecise control over size, and as a consequence, the photophysical properties. Also, the composition of CdTeS could be controlled by controlling the precursor ratios. The CdTeS QDs were successfully functionalized with a water-soluble amino acid, L -cysteine, and an amino acid derivative, N-acetyl- L -cysteine. Red-emissive L -cysteine-functionalized CdTeS QDs interacted with yellow-emissive carbon dots. The fluorescence intensity of carbon dots increased upon interaction with CdTeS QDs. This study proposes a mild method that allows to grow QDs with an ultraprecise control over the photophysical properties and shows the implementation of Cd-based QDs to enhance the fluorescence intensity of different fluorophores with fluorescence wavelength at higher energy bands. [ABSTRACT FROM AUTHOR]

In particle separation applications, conventional syringe pumps are widely used to supply fluid flow into microchannels at a controlled flow rate. However, their bulky structures lack the development of compact particle separation systems which is essential for all LoC (Lab on a Chip) systems. In this study, we designed and fabricated a peristaltic micropump which can be integrated into an inertial particle separation microchannel at the same layer with a compact design. Since inertial particle separation can be done without a need for an external force field, we aimed to develop a μTAS (Micro Total Analysis Systems) system which is able to realize particle separation in an integrated micropump-microchannel system. The circular micropump channel made of two PDMS layers and its width is optimized. The 3D-Printed micropump is actuated by a stepper motor, and the rate of pumped fluid is monitored by an LCD screen connected and programmed to system according to the system parameters. Micropump has a theoretical capacity of supplying particle carrying fluid at the flow rate of 25.47 ml/min when the stepper motor is rotated at 330 rpm.