Fabrication of capacitive yarn torsion sensors based on an electrospinning coating method

Abstract

A yarn‐based capacitive torsion sensor was produced using a simple electrospinning coating method. It was expected that nonwoven nanofiber mats, as a coating layer, would exhibit excellent performance owing to their high surface area and porous three‐dimensional nonwoven structure, which is more deformable than that of films. The electrospinning process was investigated by image analysis to generate a suitable structure of the nanofiber coating layer. The thickness of the layer was controlled by varying the electrospinning coating time (10, 20 and 30 min). Yarn sensors with coating layers of different thicknesses were manufactured by twisting two coated fibers, while simultaneously measuring the capacitance. The best sensitivity was observed with the 10 min coated yarn, due to the largest valid twist level range. It is proposed that the distance between the electrodes and the dielectric constant of the material play an important and complex role in the capacitive response of the twisted yarn, caused by the porous three‐dimensional nonwoven structure of the coated layer and the molecular mobility of the polymer. This simple coating method is expected to be useful in a wide range of applications, such as wearable devices, by facilitating convenient fabrication and repair of the flexible sensors. Moreover, high performance of the sensor could be realized due to the structural advantage of the sensing layer. © 2019 Society of Chemical Industry

Determination of polycyclic aromatic hydrocarbons in non-alcoholic beer by mechanical stir bar sorptive extraction-gas chromatography

“…The electrospinning time was increased from 7 to 13 min. The thicker coating was obtained by increasing the electrospinning time as reported in previous studies (Choi et al 2019;Jang et al 2019). In lower electrospinning time, the fabricated coating was too thin; consequently, the mechanical strength of the coating was not enough, and it was deformed during the extraction by MSBSE.…”

“…The low coating thickness causes less amount of the adsorbate to adsorb and consequently the preconcentration factor to decrease. In higher electrospinning time, the uniformity of the coating thickness decreased (Choi et al 2019;Jang et al 2019). In electrospinning time of 10 min, a coating with relatively uniform thickness and a strong structure was obtained; as a result, 10 min was selected as the optimum electrospinning time.…”

Preparation of environment‐friendly hydrophilic rubber from natural rubber grafted with sodium acrylate by reactive melt mixing

“…Furthermore, the polymerization of NaAA monomers to create homopolymers of poly(sodium acrylate), [P(NaAA)], gives an advantage for enhancing the level of water swelling, forming superabsorbent polymers (SAPs), which are used in personal healthcare products and in agriculture. [28,29] Besides, the NaAA monomer is one of several suitable choices used to improve the water swelling and synthesis of hydrogels by copolymerization with other polymers, such as N-isopropylacrylamide, sodium methacrylate, [29] 2-acrylamido-2-methylpropane sulphonate, [30] poly(vinyl alcohol), [31] acrylamide copolymer, graphene oxide, [32] and so on. However, to the best of our knowledge, graft copolymers of NaAA monomer as a solid monomer onto the NR polymer to improve its hydrophilicity and to be applied as a control-release membrane have rarely been reported.…”

State-of-the-art review of advanced electrospun nanofiber yarn-based textiles for biomedical applications

“…Besides various resistivity sensors, capacitance sensors based on electrospun NYs have also been widely explored [ 221 – 223 ]. For example, one study electrospun one layer of GO/PU nanofibers onto Ni-coated cotton yarns and further interlaced the GO/PU/Ni/cotton yarns into a capacitive sensor with a textile weaving structure [222] .…”