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Fiber flexible strain sensors have the characteristics of small volume, light weight, good flexibility, easy deformation/recovery, and easy weaving. They can conform to various complex surfaces and endure various deformations, such as twisting and bending. Furthermore, the simple preparation process of fiber sensors lowers the production cost significantly. These features make them promising candidates for applications in motion monitoring, human-machine interface, and flexible intelligent products. However, the low sensitivity and narrow sensing range of existing sensors are still major challenges for their further development. To address these challenges, this paper proposes a MXene/MXene:MWCNTs@TPU fiber sensor, which adopts a two-step pre-stretching strategy to modify the porous TPU fiber surface with MXene and MWCNTs. The graded porous TPU fibers obtained by wet spinning can achieve 805 % stretching, providing a reliable substrate support for the fiber sensor, the combination of multi-dimensional conductive materials and the introduction of cracks and wrinkles enhance the sensitivity 277 and sensing range 510 % of the fiber sensor. The fiber sensor can detect various human motions and gestures by directly attaching to the skin or weaving into textiles, and can also be applied to information encryption transmission, demonstrating its huge potential in human health monitoring, intelligent flexible electronic products and encrypted communication. [Display omitted] [ABSTRACT FROM AUTHOR]

With the development of wearable intelligent devices, flexible textiles integrate high-performance sensing, electromagnetic shielding and Joule heating show broad application prospects. However, it is still difficult to improve all the performance simultaneously through simple methods. Here, we have prepared MXene/PU composite fiber film with multilayer porous network structure by using the electrospinning spraying alternate operation process. This film has ultra-high sensitivity (GF= 77,751), super large detection range (400%) and ultra-low detection limit (0.05%). Secondly, the multilayer fiber film has excellent EMI shielding performance (EMI SE=38 dB), and the EMI shielding capacity of the multilayer film can still exceed the commercial standard when it is stretched to 20%. Finally, the multilayer fiber film shows better Joule heating performance, including lower voltage drive (2 V) and faster thermal response (12 s). The excellent performance of the composite come from the synergistic effect of MXene and the unique multi-layer porous network structure. Among them, MXene provides excellent conductivity, electrothermal and electromagnetic shielding performance. The layered porous network structure can store the strain in advance and form a parallel circuit, which improves the sensing range, increases the transmission path of electromagnetic waves, and realizes the homogeneity of Joule heating. In addition, the outer PU slows down the invasion of oxygen, thus slows down the oxidation of MXene, and ensures the performance of materials in a long time. The multilayer fiber film has been proved to be suitable for sensing at low temperature, and has broad application prospects in wearability. [Display omitted] [ABSTRACT FROM AUTHOR]

Noble metal nanostructures with localized surface plasmon resonance (LSPR) effect can be employed to enhance the light absorption ability of photocatalysts. However, it has been a challenge to control the size and morphology of noble metal nanostructures to manipulate the LSPR wavelength and improve the performance of photocatalysts. Herein, an Ag dendrite (AgD) composed of Ag nanorods with different sizes was facilely constructed by a displacement reaction, and sunlight-driven LSPR-enhanced core-shell AgD/g-C 3 N 4 composite photocatalysts (AgD-CN) were synthesized by thermal polymerizing mixtures of melamine and different amounts of AgD. This core-shell AgD-CN improved the stability of AgD and made full use of the near-field enhancement effect of AgD's LSPR, resulting in a broad light absorption band. AgD-CN-15 showed the highest photogenerated electron-hole pair separation rate and the best photocatalytic performance when the addition amount of AgD was 3 wt%. The degradation rate of RhB by AgD-CN-15 reached 95.20% after sunlight irradiation for 60 min, and its reaction rate constant was 5.2 times that of the pristine g-C 3 N 4. Moreover, ·OH, h+ and ·O 2 - were found to be the main active species. AgD is easy to prepare and can broaden the light absorption wavelength range and significantly enhance light absorption ability of photocatalysts, which provides a new method to improve the performance of LSPR-enhanced photocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

Wearable flexible sensors have a broad applications prospect in human motion and health monitoring. However, designing and manufacturing ultra-stable sensors with wide operating ranges and extremely low detection limits remain a challenging task. In this paper, a heterogeneous-structured fibrous membrane was constructed using the electrospinning process and subsequent ultrasonic homogenizer treatment. The fibrous membrane is composed of brush-like thermoplastic polyurethane (TPU) fibers, which are embedded with carbon nanotubes decorated with silver nanoparticles (AgNPs@CNTs). A dual-function sensor for strain and humidity based on the fiber membrane was designed. As a strain sensor, it has an ultra-low detection limit (0.05 %), an ultra-wide sensing range of 600 %, and excellent stability (100,000 cycles of stretch/release operation at 50 % strain). As a humidity sensor, it can achieve fast response as low as 1 s. With excellent sensing capabilities in terms of strain and humidity, the fiber membrane can be used to monitor breathing, pulse, and limb movement, as well as non-contact sensing, such as sensing the vibration of guitar strings or monitoring footsteps. The versatility and manufacturability of fiber membranes provide a new way for the application of wearable sensors in health monitoring and motion tracking. [Display omitted] • A brush-like TPU fibrous membrane decorated with AgNPs@CNTs was constructed by ultrasonic homogenizer process. • As a strain sensor, it has a large sensing range (0.05 - 600 %) and ultra-high cycle stability (100,000 cycles), which can be used for non-contact sensing. • As a humidity sensor, it exhibited a fast humidity response time as low as 1 s due to the hydrophobic surface and heterogeneous structure. [ABSTRACT FROM AUTHOR]