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Flexible electronic devices have attracted considerable attention in recent years. Textile fabrics have been widely used to fabricate flexible strain sensors owing to their high flexibility. However, the elasticity of ordinary textile fabrics is low, which limits their strain sensing range. In this article, we used a simple method to fabricate flexible strain sensing fabrics (FSSFs) through the coating of graphene oxide (GO) nanosheets on elastic nylon/polyurethane (nylon/PU) fabric, followed by reduction of GO with sodium borohydride. The reduced graphene oxide (RGO) nanosheets were adsorbed on the elastic fabrics to impart electrical conductivity to the fabrics. The coated fabrics were characterized with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Raman scattering spectroscopy. The electromechanical performance and strain sensing properties of the FSSF were investigated. The fabricated strain sensor exhibited high sensitivity, a large workable strain range (0–30%), fast response and great stability. The mechanical property of fabrics did not change remarkably after the treatment with RGO. The surface resistance of the RGO/nylon/PU only increased from ∼112 KΩ/m 2 to ∼154 KΩ/m 2 after 8 washing cycles, exhibiting good washability. Furthermore, real-time monitoring of human motions, such as bending of finger and rotation of wrist, was achieved by the as-prepared FSSF. The RGO/nylon/PU fabrics as flexible strain sensors have potential applications in wearable electronic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • The expandable graphite-based cement composite (GCC) was fabricated. • The GCC exhibits with accurate and sensitive temperature sensing performance. • The GCC exhibits excellent mechanical and sensing stability when exposed to flame. • The GCC can be easily integrated into a building and transmit a fire alert. Fire alarms in buildings are essential for safety. However, due to the poor conductivity of cement, it remains a challenge to detect fire without the assistance of other monitoring equipment. In this study, a fire alarm cement composite containing expandable graphite, carbon fiber, and ordinary Portland cement that can achieve ultrasensitive temperature monitoring and indoor climate control in a building is developed. Homogeneously distributed expandable graphite in this smart cement rapidly expands under high temperatures, forming new electrically conductive pathways. This results in excellent temperature sensing performance, with a temperature coefficient of resistance of − 0.467 %/°C in the range of 220 °C–400 °C. The smart cement can be easily integrated into a building to transmit a fire alert to a computer, mobile phone, or visual alarm device in a timely manner. Furthermore, this smart cement exhibits higher flexural strength in harsh environments compared to ordinary cement. This smart cement exhibits potential to considerably broaden cement applications and be highly desirable for next-generation smart building materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A flexible and highly sensitive strain sensor was developed by using carbonized biomass Juncus effusus fiber. • The 3D fractal composite structure showed robust mechanical strength and excellent sensitivity. • Reliable sensing performance was achieved with mechanism revealed. • Potential applications include health care monitoring and human motion monitoring were demonstrated. • The promising potential of energy conversion and harvesting was demonstrated. Fabricating strain sensors with environmental-friendly, stretchable, and highly sensitive properties remains challenging. Nature has designed an abundance of biomaterials with distinctive biological structures, which may promote the development of ideal strain sensors. Herein, we present a carbonized Juncus effusus (CJE) fiber-based wearable electronic for strain sensing and energy harvesting. The CJE strain sensor demonstrated a combined superiority of large tolerable strain (over 80%), high sensitivity (GF 4.5–31.0), low detection limit (0.1% strain), fast response (within 100 ms), and excellent durability (3500 cycles), which benefit from the self-similar and homogenous three-dimensional (3D) networks of CJE fibers. Moreover, CJE-based woven fabrics exhibited enhanced sensing characteristics (GF up to 101.9, over 110% strain) and great application prospects as triboelectric nanogenerators (TENGs). Finally, the applications in detecting human activities and energy transformation were evaluated in detail. The structural advantages made CJE as a promising candidate for the feasible integration of flexible strain sensors and portable power source in wearable electronics. [ABSTRACT FROM AUTHOR]

• A core-sheath sensing yarns was fabricated via scalable friction spinning. • The yarn exhibited excellent heat resistance and stretchability simultaneously. • High-temperature alarm could be transmitted through stretching and thermosensation. Electronic textiles with functions of temperature monitoring and human motion detection have attracted considerable interest, especially those which can be operated under extreme conditions such as high temperature. However, the restricted working conditions and poor stretchability have limited the practical application of most reported electronic textiles. Herein, we report a facile and scalable strategy to fabricate flame-resistant sensing yarn with a core–sheath structure for temperature monitoring and strain sensor applications via a large-scale spinning technique. The hierarchical yarn comprises a spandex filament as the core, carbon nanotube (CNT)-coated aramid fibers as the middle layer, and aramid fibers as the sheath. The obtained spandex/CNT@Aramid/Aramid (SCAA) yarn exhibited stretchability up to 160 % with excellent thermal resistance, outstanding thermal insulation performance, and temperature monitoring ability within a wide-range of 50–400 °C. Additionally, SCAA-based textiles showed excellent strain sensing performance in a wide operating temperature range (0–300 °C). Based on the above, a SCAA-based textiles which can transmit high-temperature alarms through active (stretching) and passive (thermosensation) modes was designed, enabling temperature monitoring presenting at extremely high temperatures. We believe this work will contribute to the development of practical sensing e-textiles towards applications in harsh environment. [ABSTRACT FROM AUTHOR]

• Durable core-sheath electro-thermochromic CNT/cotton composite yarn was fabricated. • The yarn shows excellent mechanical properties and thermochromic performance. • The yarn exhibits excellent electrified heating performance with stability. • The yarn is durable against mechanical deformations, washing and chemicals. • The color of the yarn can be tuned by changing the applied current for design. A core-sheath nanocomposite yarn, with CNT/cotton composite yarn (CCY) as the core and nanofibrous polyurethane/temperature sensitive ink as the sheath, was fabricated to generate highly robust and durable electro-thermochromic performance. Due to its novel core-sheath nanocomposite structure, the as-fabricated electro-thermochromic composite yarn (ECCY) brought together the excellent mechanical properties and electrothermal properties together with electrochromic performance. The ECCY exhibited excellent electrified heating performance with stability even after 100 cycles of heating/cooling. Moreover, the ECCY showed excellent durability against repeated bending, twisting and stretching, washing and even soaking in acid and alkali solutions. The color of ECCY was successfully tuned via changing the applied current. In addition, the ECCY was used to design different patterns and to form a fabric, resulting in color conversion patterns/fabrics when applying/releasing a current. This work provides a novel strategy of developing electro-thermochromic composite yarn by designing the core-sheath micro-nano fibrous composite structure. The highly robust and durable performance of yarn will benefit its applications as wearable electronics. [ABSTRACT FROM AUTHOR]

• Implementing in situ hydrothermal growth of Cu NPs on textiles. • Introducing polydopamine as a template to facilitate growing nanoparticles. • Fibrous structure has been preserved with nanoparticles deposited on fibers. • Durable and highly-flexible textile based wearable sensor was developed. Incorporating conductive components into fibrous structure for wearable applications has attracted research attention recently. However, utilizing the flexibility and wearability of textiles to maintain a stable and durable wearable performance is a big challenge, as the intrinsic properties of textiles and the conductivity of the incorporated components have to work synergically in the fibrous system without compromising. In this work, polydopamine-templated PET fabrics were prepared to grow copper nanoparticles (Cu NPs) on the surface of the knitted PET fabrics. The surface morphology, chemical composition and crystalline structure of the Cu NP-coated PET fabrics were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results showed that Cu NP layer was successfully deposited onto the polydopamine-templated PET fabrics. The fabrics showed excellent electrical conductivity due to the loading of Cu NPs. The unique knitted structure together with the durable deposition of Cu NPs resulted in negative change in electrical resistance of the fabrics under strains, granting the fabrics the potential in wearable applications. The Cu NP-coated PET fabrics were demonstrated to be applicable as wearable strain sensors and electrical heaters. [ABSTRACT FROM AUTHOR]