A facile approach to fabricate highly sensitive, flexible strain sensor based on elastomeric/graphene platelet composite film

This work developed a facile approach to fabricate highly sensitive and flexible polyurethane/graphene platelets composite film for wearable strain sensor. The composite film was fabricated via layer-by-layer laminating method which is simple and cost-effective; it exhibited outstanding electrical conductivity of 1430 ± 50 S/cm and high sensitivity to strain (the gauge factor is up to 150). In the sensor application test, the flexible strain sensor achieves real-time monitoring accurately for five bio-signals such as pulse movement, finger movement, and cheek movement giving a great potential as wearable-sensing device. In addition, the developed strain sensor shows response to pressure and temperature in a certain region. A multifaceted comparison between reported flexible strain sensors and our strain sensor was made highlighting the advantages of the current work in terms of (1) high sensitivity (gauge factor) and flexibility, (2) facile approach of fabrication, and (3) accurate monitoring for body motions

Mechanical, Toughness and Thermal properties of 2D Material- Reinforced Epoxy Composites

Developing epoxy composites with high thermal conductivity and excellent mechanical properties becomes imperative in electronic and aerospace industries. This study investigates and compares the effect of adding boron nitride (BN) sheets and graphene platelets (GnPs) on the mechanical properties and thermal conductivity of epoxy resin. The study shows that incorporation of BN or GnPs into epoxy matrix significantly enhanced both mechanical properties and thermal conductivity of epoxy composites. At fractions ranging 1–4 wt%, GnPs/epoxy composites provide higher Young’s modulus, fracture toughness (K1c) and critical stress energy release rate (G1c) compared to BN/epoxy composites. The thermal conductivity of the epoxy composites is up to the maximum of 0.33 Wm 1 K 1 at 4 wt% of GnP loading, which is much higher than that of the composites filled with the same loading of BN (0.23 Wm 1 K 1 ). The study emphasizes the importance of adding thin nanosheets (thickness 3–5 nm) at low loadings in developing epoxy composites to achieve desired mechanical and thermal properties

Differential Requirement for Utrophin in the Induced Pluripotent Stem Cell Correction of Muscle versus Fat in Muscular Dystrophy Mice

Duchenne muscular dystrophy (DMD) is an incurable degenerative muscle disorder. We injected WT mouse induced pluripotent stem cells (iPSCs) into mdx and mdx∶utrophin mutant blastocysts, which are predisposed to develop DMD with an increasing degree of severity (mdx <<< mdx∶utrophin). In mdx chimeras, iPSC-dystrophin was supplied to the muscle sarcolemma to effect corrections at morphological and functional levels. Dystrobrevin was observed in dystrophin-positive and, at a lesser extent, utrophin-positive areas. In the mdx∶utrophin mutant chimeras, although iPSC-dystrophin was also supplied to the muscle sarcolemma, mice still displayed poor skeletal muscle histopathology, and negligible levels of dystrobrevin in dystrophin- and utrophin-negative areas. Not only dystrophin-expressing tissues are affected by iPSCs. Mdx and mdx∶utrophin mice have reduced fat/body weight ratio, but iPSC injection normalized this parameter in both mdx and mdx∶utrophin chimeras, despite the fact that utrophin was compromised in the mdx∶utrophin chimeric fat. The results suggest that the presence of utrophin is required for the iPSC-corrections in skeletal muscle. Furthermore, the results highlight a potential (utrophin-independent) non-cell autonomous role for iPSC-dystrophin in the corrections of non-muscle tissue like fat, which is intimately related to the muscle

Mechanically robust, corrosion and impact resistance polyimide nanofiber/epoxy composite by mechanochemical fabrication

This study aimed to explore the application of a mechanochemical method for effectively integrating polyimide nanofibers, which are widely recognized for their outstanding thermal and mechanical properties, into an epoxy resin matrix. The researchers observed an 87.5% reduction in the diameter of polyimide nanofibers after mechanical treatment. The dispersion, compatibility, and interface between the nanofibers and epoxy matrix were analyzed using molecular dynamics simulations and scanning electron microscopy. The addition of polyimide nanofibers significantly increased the binding energy of the composite, resulting in a 52.8% improvement. Moreover, compared to pure epoxy resin, the inclusion of modified polyimide nanofibers led to a 21.9% increase in tensile strength and an 18.8% increase in impact strength. The PI/epoxy composite also exhibited a 15.6% increase in tensile strength and a 16.4% increase in impact strength. Additionally, electrochemical corrosion analysis showed that the PI/epoxy composite had excellent corrosion resistance. In conclusion, due to the exceptional mechanical properties and strong interfacial adhesion of polyimide nanofibers, the PI/epoxy resin composite demonstrated significant overall performance improvement compared to pure epoxy resin. Highlights: Mechanochemical method to disperse polyimide fiber, shorter and finer fibers were obtained Improve performance by adding small amounts Microscopic analysis of composites by Materials Studio, PIENFs efficiently improved the interaction on the phase interface Experiments have verified that PIENFs could make the mechanical properties and corrosion resistance.</p