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Textile-based wearable electronics have drawn increasing attention in recent years, but stable and durable conductive mechanism on textiles has been the challenge. In this study, we propose to fabricate a liquid metal circuit on textile substrates for flexible antennas and wearable sensors via screen printing method. The breakage of liquid metal circuit on cotton/lycra elastic fabrics can be repaired by pressing or heating, and the patterned liquid metal circuits can be removed using sodium hydroxide solution. Furthermore, the liquid metal circuit was designed as a pressure switch for thermal management system with the temperature precisely controllable by tuning the applied pressure. The liquid metal circuit was further designed as a flexible near field communication (NFC) antenna, providing identification capacity such as replacing campus card and protecting children. The maximum bending angle and effective distance of the NFC tag are determined to be 150 and 17.8 mm, respectively. In addition, the as-prepared liquid metal-based fabric sensors can accurately human motion detection in real time, exhibiting great potential in flexible wearable electronics. [ABSTRACT FROM AUTHOR]

The development of wearable electronic devices has greatly stimulated the research interest of textile-based strain sensors, which can effectively combine functionality with wearability. In this work, the fabrication of highly stretchable and compressible strain sensors from weft-knitted spacer fabric was reported. Carbon nanotubes and polypyrrole were deposited on the surface of fabric via an in situ polymerization approach to reduce the electrical resistance. The as-fabricated WSP-CNT-PPy strain sensor exhibits high electrical conductivity and stable strain-sensing performance under different stretching deformations. The WSP-CNT-PPy strain sensor can be stretched up to 450% and compressed to 60% with a pressure of less than 50 KPa, which can be attributed to the unique loop and interval filament structures. The distinguishing response efficiency of WSP-CNT-PPy can effectively detect faint and strenuous body movements. In addition, the electrochemical behavior of WSP-CNT-PPy was also characterized to study the comprehensive properties. The electro-heating performance was also evaluated for feasible Joule heater applications. This work demonstrates the practicability of WSP-CNT-PPy strain sensor fabric for real-time monitoring in promising wearable garments. [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]