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This paper develops four novel warp-knitted structures with two bars of the one-in one-out threading mode and describes the investigation of electromagnetic interference (EMI) shielding metal meshes composed of contiguous ultra-fine metal wires fabricated using warp-knitting technology. The mechanical properties, electrical conductivity, and microwave shielding effectiveness (SE) of the flexible meshes are assessed in terms of the mesh structure, mesh material, and warp run-in parameter. The results reveal that the metal mesh has a flexible and stable mechanical property, good electrical conductivity, and optimal EMI performance when the mesh structure is open lap atlas. The gold-coated molybdenum mesh exhibits the lowest electrical resistivity (5.18 × 10−5 ohm/sq) and optimal average EMI SE (–21.04 dB), making it a candidate for EMI shields for intelligent wearable electronic devices. The warp run-in can adjust the EMI SE, and the optimum average EMI SE (–25.52 dB) can be obtained when the warp run-in is set at the 2580 rack. Moreover, the warp-knitted metal meshes show desirable EMI shielding efficiency persisting at >70% even at large strain deformations and under cyclic bending and twisting deformations. Conductive warp-knitted meshes with a millimeter period and micron-scale wire diameter exhibit an adequately large scale, satisfactory mechanical stability, excellent flexibility, permanent conductivity, and strong microwave reflection, simultaneously. Moreover, the EMI SE of warp-knitted metal mesh reaches the protection level (–20 dB) prescribed by standard electronic devices. Therefore, the warp-knitted metal meshes show great potential in flexible and wearable EMI shielding devices. [ABSTRACT FROM AUTHOR]

Multifunctional flexible pressure sensors with high sensitivity and a wide sensing range can meet the requirements of various complex applications. Herein, metal (Au or Ag) nanoparticles (NPs) are introduced onto a MXene-coated nonwoven fabric (MNWF) using a self-reduction strategy to build a "brick–mortar" hierarchical structure (AuNPs or AgNPs@MNWF). This method is green and environmentally friendly because the self-reduction properties of MXene endow noble metal NPs with uniform sizes and controlled densities to be introduced without using reducing agents or surfactants. The introduction of metal NPs and the construction of composites considerably improve the piezoresistive properties of MNWF, resulting in a 4-fold increase in sensor sensitivity (a linear sensitivity of 24.5 kPa−1 at 0–100 kPa). Moreover, the excellent electrical conductivity and unique plasmonic effect of metal NPs also contribute toward enhancing the heating performance and expanding the antibacterial applications of MNWF. In particular, compared to MNWF, AgNPs@MNWF as a dual energy-driven flexible wearable heater exhibits an electrothermal enhancement of 25.3 °C (at 7.5 V) and a photothermal enhancement of 5.6 °C (at 100 mW cm−2). Notably, the antibacterial efficiency of AgNPs@MNWF is as high as 99.9%, indicating the potential of this material for applications in the medical and health field, such as in intelligent mattresses. Overall, noble metal NPs can enhance the sensing performance as well as the Joule heating, and photothermal and antibacterial properties of MNWF. Thus, this work extends the applicability of the self-reduction strategy, providing a general strategy for expanding the applications of multifunctional fabric-based flexible sensors. [ABSTRACT FROM AUTHOR]

Highly conductive, flexible, stretchable and lightweight electrode substrates are essential to meet the future demand on supercapacitors for wearable electronics. However, it is difficult to achieve the above characteristics simultaneously. In this study, ultrafine stainless-steel fibers (with a diameter of ≈30 μm) are knitted into stainless-steel meshes (SSMs) with a diamond structure for the fabrication of textile stretchable electrodes and current collectors. The electrodes are fabricated by utilizing an electrodeposited three-dimensional network graphene framework and poly(3,4-ethylenedioxythiophene) (PEDOT) coating on the SSM substrates via a two-step electrodeposition process, which show a specific capacitance of 77.09 F g−1 (0.14 A g−1) and superb cycling stability (91% capacitance retention after 5000 cycles). Furthermore, the assembled flexible stretchable supercapacitor based on the PEDOT/reduced graphene oxide (RGO)@SSM electrodes exhibits an areal capacitance (53 mF cm−2 at 0.1 mA cm−2), a good cycling stability (≈73% capacitance retention after 5000 cycles), rate capability (36 mF cm−2 at 5 mA cm−2), stretchable stability (≈78% capacitance retention at 10% strain for 500 stretching cycles) and outstanding flexibility and stability under various bending deformations. The assembled supercapacitors can illuminate a thermometer and a light-emitting diode, demonstrating their potential application as stretchable supercapacitors. This simple and low-cost method developed for fabricating lightweight, stretchable and stable high-performance supercapacitors offers new opportunities for future stretchable electronic devices. [ABSTRACT FROM AUTHOR]

Flexible wearable strain sensors with excellent sensing performance have received widespread interest due to their superior application capability in the field of human-computer interaction, sports rehabilitation, and disease diagnosis. But at present, it is still a considerable challenge to exploit a flexible strain sensor with high sensitivity and wide sensing range that is easily manufactured, low-cost, and easily integrable into clothing. MXene is a promising material sensitive enough for flexible sensors due to its superior conductivity and hydrophilicity. The warp knitting weft insertion textile structure gives the fabric excellent elasticity, making it suitable as a flexible, stretchable substrate. Therefore, utilizing a polyester elastic fabric with a warp knitting weft insertion structure, a fabric strain sensor with high sensitivity and wide sensing range prepared by layer-by-layer self-assembly of polyvinyl alcohol layers and MXene layers is reported in this study. The strain sensor exhibits high sensitivity (up to 288.43), a wide sensing range (up to 50%), fast response time (50 ms), ultra-low detection limit (a strain of 0.067%), excellent cycle stability (1000 cycles), and good washability. Besides, affixing the MXene/polyvinyl alcohol/polyester elastic fabric strain sensor on the joints can detect the movement of limbs. Therefore, the MXene/polyvinyl alcohol/polyester elastic fabric strain sensor demonstrates potential application opportunities in smart wearable electronic devices, and the researcher can also apply this method in the production of other flexible, intelligent wearable devices. [ABSTRACT FROM AUTHOR]

One-dimensional high-performance yarns with excellent conductivity and flexibility are of considerable interest in the energy and aerospace industries. However, how to achieve highly conductivity, excellent flexibility, extreme condition durability and high mechanical performance in one fiber material is still a great challenge using economically viable materials and synthesis technologies. Herein, we report electrically conductive yarns (modified polyimide (M-PI)/reduced graphene oxide (RGO) yarns) consisting of RGO coated on the surface of nitrogen plasma M-PI yarns, which are fabricated by combining the N2 plasma pre-treatment and repeated dip-coating and reducing technique. N2 plasma treatment is used to roughen the surface of the PI yarn and introduce functional groups, contributing to improve wettability, which can provide a stronger adhesion of the graphene coating. The dip-coating and reducing process was repeated 10 times to enhance the loading mass of RGO on the PI yarns, then M-PI/RGO yarns with better conductivity property can be obtained. The effects of N2 plasma treatment power and time on the M-PI yarns and M-PI/RGO yarns are investigated and discussed. The results demonstrate that the graphene layer is uniformly and densely coated on the PI yarn when being treated at 200 W for 8 min, and the conductivity of the M-PI/RGO yarn reaches 1.51 × 102 S/m. The M-PI/RGO yarn combine the advantages of RGO and PI yarns, retaining the mechanical properties and thermal stability of PI yarn while exploiting the conductive property of RGO. In addition, the enhanced adhesion between the PI yarn and graphene coating endows the composite yarns with excellent fastness and superior flexibility. This work describes an environmentally friendly, controllable and facile method to develop flexible and conductive functional graphene-coated PI yarns with high-performance properties. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the anti-ageing effect of Yisui moxibustion on regulating the klotho protein and insulin (INS)/IGF-1 signalling cascade in d-galactose mice. Sixty male Kunming mice were randomly divided into five groups after the Morries test: the normal sodium, model, moxa cone moxibustion 1 and 2, and sham groups. The treatment and model were given d-galactose injection for 70 days, while mice in the normal sodium group were injected the same dosage of normal sodium. From day 13 after the first injection, the three treatment groups were treated every day for 58 days. The INS and klotho in the cerebral tissues were measured. p-Akt, p-FoxO3a, Klotho, SOD2 expression were observed immunohistochemically. The escape latency of mice in the model and sham were significantly prolonged, and the spanning original platform times were significantly decreased compared with the normal sodium and moxa cone moxibustion 1 and 2 (p < 0.01). The content of INS and klotho in the model was significantly lower than the normal sodium, moxa cone moxibustion 1 and 2 (p < 0.01). Compared with the model and sham, p-Akt and p-FoxO3a expression in moxa cone moxibustion 1 and 2 were markedly decreased (p < 0.05), and the expressions of klotho and SOD2 were significantly increased (p < 0.05) in hippocampal CA1. Yisui moxibustion could exert the antioxidative effect on klotho protein, which negatively regulated the insulin signalling pathway and its downstream elements in cerebral tissue and hippocampal CA1, so as to enhance learning and memory capacities, delay brain ageing. [ABSTRACT FROM AUTHOR]

Soft robots are those that can move like living organisms and adapt to the surrounding environment. Compared with traditional rigid robots, the advantages of soft robots, in terms of material flexibility, human–computer interaction, and biological adaptability, have received extensive attention. Flexible actuators based on light response are one of the most promising ways to promote the field of cordless soft robots, and they have attracted the attention of scientists in bionic design, actuation implementation, and application. First, the three working principles and the commonly used light-responsive materials for light-responsive actuators are introduced. Then, the characteristics of light-responsive soft actuators are sequentially presented, emphasizing the structure strategy, actuation performance, and emerging applications. Finally, this review is concluded with a perspective on the existing challenges and future opportunities in this nascent research frontier. [ABSTRACT FROM AUTHOR]

Interface issues urgently need to be addressed in high-performance fiber reinforced composites. In this study, different periods of O2 plasma treatment are proposed to modify twist-free polyimide (PI) filaments to improve hydrophilicity and mechanical and interfacial properties. Feeding O2 produces chemically active particles to modify the filament surface via chemical reactions and physical etching. According to the X-ray photoelectron spectroscopy (XPS) results, the PI filaments exhibit an 87.16% increase in O/C atomic ratio and a 135.71% increase in the C–O functional group after 180 s O2 plasma treatment. The atomic force microscope (AFM) results show that the root mean square roughness (Rq) of the treated PI filaments increases by 105.34%, from 38.41 to 78.87 nm. Owing to the increased surface oxygenic functional groups and roughness after O2 plasma treatment, the contact angle between treated PI filaments and water reduces drastically from the pristine state of 105.08° to 56.15°. The O2 plasma treated PI filaments also demonstrate better mechanical properties than the pristine PI filaments. Moreover, after O2 plasma treatment, the adhesion between PI filaments and poly(amic acid) (PAA) is enhanced, and the tensile strength of the polyimide/poly(amic acid) (PI/PAA) self-reinforced composites increases from 136 to 234 MPa, even causing the failure mode of the composite changes from adhesive failure to partly cohesive failure. [ABSTRACT FROM AUTHOR]

Although Ti 3 C 2 T x MXene/fabric composites have shown promise as flexible pressure sensors, the effects of MXene composition and structure on piezoresistive properties and the effects of the textile structure on sensitivity have not been systematically studied. Herein, impregnation at room temperature was used as a cost-effective and scalable method to prepare composite materials using different fabrics [plain-woven fabric, twill-woven fabric, weft plain-knitted fabric, jersey cross-tuck fabric, and nonwoven fabric (NWF)] and MXene nanosheets (Ti 3 C 2 T x , Ti 2 CT x , Ti 3 CNT x , Mo 2 CT x , Nb 2 CT x , and Mo 2 TiC 2 T x ). The MXene nanosheets adhered to the fabric surface through hydrogen bonding, resulting in a conductive network structure. The Ti 3 C 2 T x @NWF composite was found to be the optimal flexible pressure sensor, demonstrating high sensitivity (6.31 kPa -1 ), a wide sensing range (up to 150 kPa), fast response/recovery times (300 ms/260 ms), and excellent durability (2000 cycles). Furthermore, the sensor was successfully used to monitor full-scale human motion, including pulse, and a 4 × 4 pixel flexible sensor array was shown to accurately locate pressure and recognize the pressure magnitude. These findings provide a basis for the rational design of MXene/textile composites as wearable pressure sensors for medical diagnosis, human-computer interactions, and electronic skin applications.